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2026 Vol. 44, No. 4
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2026, 44(4): 1-10.
doi: 10.13205/j.hjgc.202604001
Abstract:
This study systematically investigated the occurrence， multi-dimensional spatial distribution， sources， and ecological risks of 160 pesticides in Dianchi Lake， a typical plateau lake impacted by agricultural activities. The results showed that a total of 37 pesticides were detected in the water of Dianchi Lake， with a total concentration range of 64.2 to 1132.8 ng/L （average concentration： 610.0 ng/L）. Fungicides such as boscalid （BOS）， fluopicolide （FPC）， and dimethomorph （DMM） were the dominant compounds. accounting for up to 65.0% of the total concentration. Spatially， concentrations in the southern lake region （672.5 ng/L） were significantly higher than those in the north due to intensive facility agriculture， and highly hydrophobic pesticides （e.g.， penconazole （PEN）） showed a migration trend of enrichment towards the bottom layer. Source apportionment results indicated that inflowing rivers and wastewater treatment plant effluents were the main input sources of pesticides in Dianchi Lake， with average concentrations being 7 and 9 times higher than those in the lake water， respectively. The ecological risk of pesticides to aquatic organisms in Dianchi Lake was ranked as algae > daphnia > fish. Prometryn （PMT） was identified as a high-risk factor for algae， while profenofos （PFF） and carbendazim （CBD） posed potential threats to organisms at higher trophic levels. These findings provide fundamental data and technical support for understanding the occurrence characteristics， source apportionment， and ecological risks of pesticides in typical plateau lake waters.
This study systematically investigated the occurrence， multi-dimensional spatial distribution， sources， and ecological risks of 160 pesticides in Dianchi Lake， a typical plateau lake impacted by agricultural activities. The results showed that a total of 37 pesticides were detected in the water of Dianchi Lake， with a total concentration range of 64.2 to 1132.8 ng/L （average concentration： 610.0 ng/L）. Fungicides such as boscalid （BOS）， fluopicolide （FPC）， and dimethomorph （DMM） were the dominant compounds. accounting for up to 65.0% of the total concentration. Spatially， concentrations in the southern lake region （672.5 ng/L） were significantly higher than those in the north due to intensive facility agriculture， and highly hydrophobic pesticides （e.g.， penconazole （PEN）） showed a migration trend of enrichment towards the bottom layer. Source apportionment results indicated that inflowing rivers and wastewater treatment plant effluents were the main input sources of pesticides in Dianchi Lake， with average concentrations being 7 and 9 times higher than those in the lake water， respectively. The ecological risk of pesticides to aquatic organisms in Dianchi Lake was ranked as algae > daphnia > fish. Prometryn （PMT） was identified as a high-risk factor for algae， while profenofos （PFF） and carbendazim （CBD） posed potential threats to organisms at higher trophic levels. These findings provide fundamental data and technical support for understanding the occurrence characteristics， source apportionment， and ecological risks of pesticides in typical plateau lake waters.
2026, 44(4): 11-18.
doi: 10.13205/j.hjgc.202604002
Abstract:
A method for the determination of 22 per- and polyfluoroalkyl substances （PFAS） by ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） was developed. The optimized method involves extracting particulate matter from filtered water samples with methanol， followed by combining the particulate methanol extract with the filtrate， thereby enabling efficient capture of PFAS from both dissolved and particulate phases. The samples were concentrated and purified using weak anion exchange （WAX） solid-phase extraction （SPE） columns. After nitrogen blowing， the residue was reconstituted in methanol/water （V/V=8∶2） and filtered prior to analysis by mass spectrometry， with quantification performed via the isotope internal standard method. The linear correlation coefficients （R²） of the standard curves for the 22 PFAS were all greater than 0.995， with linear ranges of 1 to 100 µg/L， detection limits of 0.2 to 0.6 ng/L， and quantification limits of 0.8 to 24 ng/L. The recovery rates of the 22 PFAS in blank water and surface water ranged from 85.3% to 139% and 76.4% to 127%， respectively， with relative standard deviations （RSD） of less than 15% （n=6）. Compared with the methods that do not involve the extraction of particulate PFAS， this method exhibited distinct advantages in the recovery rates of the 22 PFAS in surface water. These results demonstrate that the developed method is sensitive， accurate， and reliable. The incorporation of a methanol extraction step can effectively eliminate the negative bias induced by particulate adsorption， thus significantly enhancing the recovery of PFAS. This method is suitable for the quantitative determination of 22 common PFAS in surface water.
A method for the determination of 22 per- and polyfluoroalkyl substances （PFAS） by ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） was developed. The optimized method involves extracting particulate matter from filtered water samples with methanol， followed by combining the particulate methanol extract with the filtrate， thereby enabling efficient capture of PFAS from both dissolved and particulate phases. The samples were concentrated and purified using weak anion exchange （WAX） solid-phase extraction （SPE） columns. After nitrogen blowing， the residue was reconstituted in methanol/water （V/V=8∶2） and filtered prior to analysis by mass spectrometry， with quantification performed via the isotope internal standard method. The linear correlation coefficients （R²） of the standard curves for the 22 PFAS were all greater than 0.995， with linear ranges of 1 to 100 µg/L， detection limits of 0.2 to 0.6 ng/L， and quantification limits of 0.8 to 24 ng/L. The recovery rates of the 22 PFAS in blank water and surface water ranged from 85.3% to 139% and 76.4% to 127%， respectively， with relative standard deviations （RSD） of less than 15% （n=6）. Compared with the methods that do not involve the extraction of particulate PFAS， this method exhibited distinct advantages in the recovery rates of the 22 PFAS in surface water. These results demonstrate that the developed method is sensitive， accurate， and reliable. The incorporation of a methanol extraction step can effectively eliminate the negative bias induced by particulate adsorption， thus significantly enhancing the recovery of PFAS. This method is suitable for the quantitative determination of 22 common PFAS in surface water.
2026, 44(4): 19-25.
doi: 10.13205/j.hjgc.202604003
Abstract:
This study employed high-resolution mass spectrometry （HRMS）-based non-target screening to systematically identify the composition and spatial distribution characteristics of emerging contaminants （ECs） in wastewater from three functional zones of a metro maintenance station： the storeroom （S1）， the office and residential area （S2）， and the final discharge outlet （S3）. A total of 417 contaminants were detected， covering eight major categories including industrial materials， pharmaceuticals， pesticides， and natural products. Among them， 48 substances were identified with Level 1 confidence based on spectral matching. Pesticides exhibited the highest detection frequency and concentration levels， representing the primary source of contaminant load. Semi-quantitative concentration heatmaps of 24 pesticides revealed significant spatial variation： S2 exhibited the highest number and concentration of contaminants， reflecting pollution from landscaping and vector control activities in the residential area； S1 and S3 showed relatively lower levels， indicating dilution， migration， and attenuation processes within the system. Representative pesticides such as bifenox displayed clear concentration gradients across sampling points， suggesting multiple transport mechanisms such as surface runoff， hydraulic transfer， and sorption. These findings highlight the complexity and diversity of EC sources in urban transportation infrastructure wastewater， underscore the necessity of prioritizing pesticides in regulatory management， and provide fundamental data for understanding the environmental behavior of ECs and informing water environment risk assessment.
This study employed high-resolution mass spectrometry （HRMS）-based non-target screening to systematically identify the composition and spatial distribution characteristics of emerging contaminants （ECs） in wastewater from three functional zones of a metro maintenance station： the storeroom （S1）， the office and residential area （S2）， and the final discharge outlet （S3）. A total of 417 contaminants were detected， covering eight major categories including industrial materials， pharmaceuticals， pesticides， and natural products. Among them， 48 substances were identified with Level 1 confidence based on spectral matching. Pesticides exhibited the highest detection frequency and concentration levels， representing the primary source of contaminant load. Semi-quantitative concentration heatmaps of 24 pesticides revealed significant spatial variation： S2 exhibited the highest number and concentration of contaminants， reflecting pollution from landscaping and vector control activities in the residential area； S1 and S3 showed relatively lower levels， indicating dilution， migration， and attenuation processes within the system. Representative pesticides such as bifenox displayed clear concentration gradients across sampling points， suggesting multiple transport mechanisms such as surface runoff， hydraulic transfer， and sorption. These findings highlight the complexity and diversity of EC sources in urban transportation infrastructure wastewater， underscore the necessity of prioritizing pesticides in regulatory management， and provide fundamental data for understanding the environmental behavior of ECs and informing water environment risk assessment.
2026, 44(4): 26-37.
doi: 10.13205/j.hjgc.202604004
Abstract:
Tire wear particles （TWPs）， as emerging pollutants， constitute the dominant type of microplastics （MPs） in urban stormwater runoff. They are characterized by their small size， high mobility， complex composition， and significant toxicity. Current research on TWPs remains fragmented， lacking a comprehensive and coherent understanding—particularly regarding their key environmental behaviors and pollution control strategies in aquatic environments. This paper systematically analyzes the enrichment and vectoring roles of TWPs for coexisting pollutants， along with their environmental fate. It summarizes their ecotoxicological impacts， detection methodologies， the release of intrinsic additives， and their aggregation and sedimentation processes in water bodies. Drawing on insights from studies of other microplastic contaminants， the paper explores existing control technologies for TWPs across the entire pollution pathway， from source， through transport， to terminal treatment， and proposes feasible management strategies under current conditions. Future research should focus on： 1） elucidating the processes and key influencing factors of both homogeneous and heterogeneous aggregation of TWPs under real aquatic conditions； 2） examining the release extent and mechanisms of various intrinsic additives from TWPs in natural water environments； 3） evaluating the long-term performance of treatment facilities such as constructed wetlands under continuous TWPs exposure； 4） investigating the mechanisms of enzymatic degradation of TWPs； 5） integrating emerging technologies， including artificial intelligence （AI）， big data， and the Internet of Things （IoT）， to develop cost-effective detection and remediation techniques. Additionally， constructing models for TWPs release and migration is essential for assessing environmental risks.
Tire wear particles （TWPs）， as emerging pollutants， constitute the dominant type of microplastics （MPs） in urban stormwater runoff. They are characterized by their small size， high mobility， complex composition， and significant toxicity. Current research on TWPs remains fragmented， lacking a comprehensive and coherent understanding—particularly regarding their key environmental behaviors and pollution control strategies in aquatic environments. This paper systematically analyzes the enrichment and vectoring roles of TWPs for coexisting pollutants， along with their environmental fate. It summarizes their ecotoxicological impacts， detection methodologies， the release of intrinsic additives， and their aggregation and sedimentation processes in water bodies. Drawing on insights from studies of other microplastic contaminants， the paper explores existing control technologies for TWPs across the entire pollution pathway， from source， through transport， to terminal treatment， and proposes feasible management strategies under current conditions. Future research should focus on： 1） elucidating the processes and key influencing factors of both homogeneous and heterogeneous aggregation of TWPs under real aquatic conditions； 2） examining the release extent and mechanisms of various intrinsic additives from TWPs in natural water environments； 3） evaluating the long-term performance of treatment facilities such as constructed wetlands under continuous TWPs exposure； 4） investigating the mechanisms of enzymatic degradation of TWPs； 5） integrating emerging technologies， including artificial intelligence （AI）， big data， and the Internet of Things （IoT）， to develop cost-effective detection and remediation techniques. Additionally， constructing models for TWPs release and migration is essential for assessing environmental risks.
2026, 44(4): 38-46.
doi: 10.13205/j.hjgc.202604005
Abstract:
To elucidate the effects of exogenous antibiotic-resistant bacteria （ARB） exposure on wheat growth and associated bacterial community assembly， the inhibitory impacts of exogenous ARB on wheat seedling root and shoot length， shifts in root endophytic and rhizosphere bacterial communities， and the horizontal transfer of exogenous antibiotic resistance genes （ARGs） to indigenous endophytic bacteria were investigated using plate culture counting and 16S rRNA high-throughput sequencing. The results showed that exogenous ARB exposure significantly suppressed wheat seedling root and shoot growth， with inhibition rates increasing in an ARB concentration-dependent manner. At an exogenous ARB concentration of 108 CFU/mL， the inhibition rates of seedling root and shoot length reached 68.83% and 36.87%， respectively. During the period of ARB exposure， the relative abundance of Clostridium_sensu_stricto_5 in root endophytic bacteria increased rapidly， becoming the most dominant genus （45.02%） by the end of the exposure period. In contrast， Betaproteobacteriales remained the dominant order in the rhizosphere bacterial community throughout the experiment， with its relative abundance increasing continuously over time. The proportion of ARB-carrying endophytic bacteria initially decreased and then increased during exposure， showing a significant positive correlation with the relative abundances of Clostridium_sensu_stricto_5， Clostridium_sensu_stricto_1， Bacillus， and Paenibacillus （P<0.05）. In summary， exogenous ARB exposure significantly inhibits wheat seedling growth and alters the community structure of both root endophytic and rhizosphere bacteria. Sustained ARB exposure leads to the transfer of exogenous ARGs to root endophytes， and Clostridium_sensu_stricto species may act as potential hosts for ARGs in wheat seedling roots.
To elucidate the effects of exogenous antibiotic-resistant bacteria （ARB） exposure on wheat growth and associated bacterial community assembly， the inhibitory impacts of exogenous ARB on wheat seedling root and shoot length， shifts in root endophytic and rhizosphere bacterial communities， and the horizontal transfer of exogenous antibiotic resistance genes （ARGs） to indigenous endophytic bacteria were investigated using plate culture counting and 16S rRNA high-throughput sequencing. The results showed that exogenous ARB exposure significantly suppressed wheat seedling root and shoot growth， with inhibition rates increasing in an ARB concentration-dependent manner. At an exogenous ARB concentration of 108 CFU/mL， the inhibition rates of seedling root and shoot length reached 68.83% and 36.87%， respectively. During the period of ARB exposure， the relative abundance of Clostridium_sensu_stricto_5 in root endophytic bacteria increased rapidly， becoming the most dominant genus （45.02%） by the end of the exposure period. In contrast， Betaproteobacteriales remained the dominant order in the rhizosphere bacterial community throughout the experiment， with its relative abundance increasing continuously over time. The proportion of ARB-carrying endophytic bacteria initially decreased and then increased during exposure， showing a significant positive correlation with the relative abundances of Clostridium_sensu_stricto_5， Clostridium_sensu_stricto_1， Bacillus， and Paenibacillus （P<0.05）. In summary， exogenous ARB exposure significantly inhibits wheat seedling growth and alters the community structure of both root endophytic and rhizosphere bacteria. Sustained ARB exposure leads to the transfer of exogenous ARGs to root endophytes， and Clostridium_sensu_stricto species may act as potential hosts for ARGs in wheat seedling roots.
2026, 44(4): 47-56.
doi: 10.13205/j.hjgc.202604006
Abstract:
Wastewater containing high concentrations of sulfamethoxazole （SMX） significantly inhibits anaerobic microorganisms， leading to reduced organic matter degradation efficiency and decreased methane yield in anaerobic digestion processes. This study investigated the effects of adding short-chain （C6-HSL） and long-chain （C12-HSL） signaling molecules on the construction， performance， and antibiotic resistance genes （ARGs） of anaerobic electroactive biofilm systems within a microbial electrochemically coupled anaerobic digestion （MEC-AD） system. Results indicated that， compared to the control group （without added signaling molecules）， the relative SMX removal rates in the C6-HSL group （T1）， the C12-HSL group （T2）， and the dual-treated group （T3） increased by 9.26%， 7.44%， and 10.67%， respectively， while methane production rates increased by 20.4%， 16.9%， and 23.1%， respectively. The signaling molecule N-acyl-γ-lactones （AHLs） significantly enhanced the attachment of electroactive microorganisms to the anode electrode by promoting extracellular polymer production. Microbial community analysis revealed that AHLs enhanced microbial diversity and regulated the abundance of key functional bacteria. At the genus level， Georgenia exhibited significantly differential responses to different signal molecules： relative abundance increased by 16.77% and 36.47% in T1 and T3 groups， respectively， while decreasing by 15.99% in T2 group. ARGs analysis results showed that single signaling molecules increased the abundance of intl1， sul1， and sul2. However， the T3 group exhibited a milder response， with sul2 abundance decreasing by 4.92% compared to the control group. This finding indicates that the synergistic effect of composite AHLs helps mitigate the amplification of potential ARG-carrying bacteria. This study reveals， for the first time， the role of short-chain and long-chain composite AHLs in promoting electroactive biofilm formation， maintaining microbial community stability， and regulating ARG transmission risks. It can provide a feasible pathway for developing antibiotic wastewater treatment and risk management strategies based on quorum sensing regulation.
Wastewater containing high concentrations of sulfamethoxazole （SMX） significantly inhibits anaerobic microorganisms， leading to reduced organic matter degradation efficiency and decreased methane yield in anaerobic digestion processes. This study investigated the effects of adding short-chain （C6-HSL） and long-chain （C12-HSL） signaling molecules on the construction， performance， and antibiotic resistance genes （ARGs） of anaerobic electroactive biofilm systems within a microbial electrochemically coupled anaerobic digestion （MEC-AD） system. Results indicated that， compared to the control group （without added signaling molecules）， the relative SMX removal rates in the C6-HSL group （T1）， the C12-HSL group （T2）， and the dual-treated group （T3） increased by 9.26%， 7.44%， and 10.67%， respectively， while methane production rates increased by 20.4%， 16.9%， and 23.1%， respectively. The signaling molecule N-acyl-γ-lactones （AHLs） significantly enhanced the attachment of electroactive microorganisms to the anode electrode by promoting extracellular polymer production. Microbial community analysis revealed that AHLs enhanced microbial diversity and regulated the abundance of key functional bacteria. At the genus level， Georgenia exhibited significantly differential responses to different signal molecules： relative abundance increased by 16.77% and 36.47% in T1 and T3 groups， respectively， while decreasing by 15.99% in T2 group. ARGs analysis results showed that single signaling molecules increased the abundance of intl1， sul1， and sul2. However， the T3 group exhibited a milder response， with sul2 abundance decreasing by 4.92% compared to the control group. This finding indicates that the synergistic effect of composite AHLs helps mitigate the amplification of potential ARG-carrying bacteria. This study reveals， for the first time， the role of short-chain and long-chain composite AHLs in promoting electroactive biofilm formation， maintaining microbial community stability， and regulating ARG transmission risks. It can provide a feasible pathway for developing antibiotic wastewater treatment and risk management strategies based on quorum sensing regulation.
2026, 44(4): 57-66.
doi: 10.13205/j.hjgc.202604007
Abstract:
Given the widespread occurrence of low C/N ratios in treated wastewater effluent and the instability of conventional liquid carbon sources， it is necessary to investigate solid-phase carbon sources in terms of composition and design. The goal is to optimize both the quantity and quality of carbon release for denitrification under low C/N conditions and to extend research into the environmental behavior of emerging contaminants. In this study， nine composite solid-phase carbon sources were prepared from straw， sawdust， and corncob as natural cellulose materials with different PHBV-to-cellulose mass ratios. Their carbon release characteristics were evaluated via dynamic release experiments combined with dissolved organic carbon （DOC） analysis， UV-Vis spectroscopy， and excitation-emission matrix （EEM） fluorescence spectroscopy. The results showed that with identical carbon-source components， increasing the proportion of cellulose caused corncob-based solid-phase carbon sources to exhibit release patterns that differed from， and in some cases were opposite to， those of straw- and sawdust-based systems. When the carbon-source composition was the same， increasing the proportion of straw or sawdust accelerated the release rate， increased total release and release duration， reduced the aromaticity and molecular weight of the released dissolved organic matter （DOM）， and promoted the release of protein-like DOM such as tryptophan and tyrosine， indicating that material ratios can synergistically regulate DOM bioavailability. Under identical ratio conditions， corncob-based composite carbon sources outperformed straw- and sawdust-based systems on multiple parameters： they achieved a moderate total carbon release while maintaining release durations exceeding 134 hours， thereby ensuring a stable carbon supply. The DOM they released exhibited lower aromaticity， smaller molecular weight， and a lower proportion of humic substances， indicating higher bioavailability. Overall， the corncob-based system demonstrated significant advantages in both bioavailability and engineering application potential.
Given the widespread occurrence of low C/N ratios in treated wastewater effluent and the instability of conventional liquid carbon sources， it is necessary to investigate solid-phase carbon sources in terms of composition and design. The goal is to optimize both the quantity and quality of carbon release for denitrification under low C/N conditions and to extend research into the environmental behavior of emerging contaminants. In this study， nine composite solid-phase carbon sources were prepared from straw， sawdust， and corncob as natural cellulose materials with different PHBV-to-cellulose mass ratios. Their carbon release characteristics were evaluated via dynamic release experiments combined with dissolved organic carbon （DOC） analysis， UV-Vis spectroscopy， and excitation-emission matrix （EEM） fluorescence spectroscopy. The results showed that with identical carbon-source components， increasing the proportion of cellulose caused corncob-based solid-phase carbon sources to exhibit release patterns that differed from， and in some cases were opposite to， those of straw- and sawdust-based systems. When the carbon-source composition was the same， increasing the proportion of straw or sawdust accelerated the release rate， increased total release and release duration， reduced the aromaticity and molecular weight of the released dissolved organic matter （DOM）， and promoted the release of protein-like DOM such as tryptophan and tyrosine， indicating that material ratios can synergistically regulate DOM bioavailability. Under identical ratio conditions， corncob-based composite carbon sources outperformed straw- and sawdust-based systems on multiple parameters： they achieved a moderate total carbon release while maintaining release durations exceeding 134 hours， thereby ensuring a stable carbon supply. The DOM they released exhibited lower aromaticity， smaller molecular weight， and a lower proportion of humic substances， indicating higher bioavailability. Overall， the corncob-based system demonstrated significant advantages in both bioavailability and engineering application potential.
2026, 44(4): 67-78.
doi: 10.13205/j.hjgc.202604008
Abstract:
The effluent from municipal wastewater treatment plants （WWTPs） is characterized by a low carbon-to-nitrogen （C/N） ratio in China. Achieving deep nitrogen removal using traditional heterotrophic denitrification processes requires substantial external carbon source addition， leading to high operational costs and potential secondary pollution. Nitrate-dependent ferrous oxidation （NDFO） presents a promising alternative denitrification technology. However， it faces bottlenecks such as unsustainable iron sources and surface passivation. In this study， a pilot-scale electrochemical-biological coupled system （CF-Fe-CS/NAFO） was constructed， featuring a built-in composite cathode （5% apparent filling rate of carbon felt-iron-chitosan， CF-Fe-CS）， an effective volume of 200 L， and a treatment capacity of 100 L/d. A constant potential of -1.0 V （vs. Ag/AgCl） was applied to the cathode to achieve the in-situ electrochemical reduction of Fe（Ⅲ）. In the test reactor， during stable operation from day 16 to 60 with a hydraulic retention time （HRT） of 48 h and synthetic wastewater containing 15 mg/L NO3--N， the effluent NO3--N concentration remained consistently below 6.5 mg/L， with a total nitrogen （TN） removal efficiency of 50% to 60%. In contrast， the control reactor （without an applied potential） showed an effluent NO3--N concentration above 12 mg/L and a TN removal efficiency below 20%. During continuous operation from day 61 to 74 using real secondary sedimentation tank effluent from a WWTP （influent NO3--N： 15.29 mg/L）， the system reduced the effluent NO3--N to 6.06 mg/L， maintaining a TN removal efficiency above 50%. From day 74 to 98， as the HRT was sequentially reduced from 48 h to 24 h， 12 h， 6 h， and 3 h， the corresponding effluent NO3--N concentrations increased to 9.5 mg/L， 11.9 mg/L， 13.6 mg/L， and 14.6 mg/L， with TN removal efficiencies of 32.6%， 19.9%， 10.9%， and 5.8%， respectively. These results demonstrate that the CF-Fe-CS/NAFO electrochemical system can achieve long-term， stable， and advanced nitrogen removal from WWTP secondary effluent without the need for an external organic carbon source.
The effluent from municipal wastewater treatment plants （WWTPs） is characterized by a low carbon-to-nitrogen （C/N） ratio in China. Achieving deep nitrogen removal using traditional heterotrophic denitrification processes requires substantial external carbon source addition， leading to high operational costs and potential secondary pollution. Nitrate-dependent ferrous oxidation （NDFO） presents a promising alternative denitrification technology. However， it faces bottlenecks such as unsustainable iron sources and surface passivation. In this study， a pilot-scale electrochemical-biological coupled system （CF-Fe-CS/NAFO） was constructed， featuring a built-in composite cathode （5% apparent filling rate of carbon felt-iron-chitosan， CF-Fe-CS）， an effective volume of 200 L， and a treatment capacity of 100 L/d. A constant potential of -1.0 V （vs. Ag/AgCl） was applied to the cathode to achieve the in-situ electrochemical reduction of Fe（Ⅲ）. In the test reactor， during stable operation from day 16 to 60 with a hydraulic retention time （HRT） of 48 h and synthetic wastewater containing 15 mg/L NO3--N， the effluent NO3--N concentration remained consistently below 6.5 mg/L， with a total nitrogen （TN） removal efficiency of 50% to 60%. In contrast， the control reactor （without an applied potential） showed an effluent NO3--N concentration above 12 mg/L and a TN removal efficiency below 20%. During continuous operation from day 61 to 74 using real secondary sedimentation tank effluent from a WWTP （influent NO3--N： 15.29 mg/L）， the system reduced the effluent NO3--N to 6.06 mg/L， maintaining a TN removal efficiency above 50%. From day 74 to 98， as the HRT was sequentially reduced from 48 h to 24 h， 12 h， 6 h， and 3 h， the corresponding effluent NO3--N concentrations increased to 9.5 mg/L， 11.9 mg/L， 13.6 mg/L， and 14.6 mg/L， with TN removal efficiencies of 32.6%， 19.9%， 10.9%， and 5.8%， respectively. These results demonstrate that the CF-Fe-CS/NAFO electrochemical system can achieve long-term， stable， and advanced nitrogen removal from WWTP secondary effluent without the need for an external organic carbon source.
2026, 44(4): 79-89.
doi: 10.13205/j.hjgc.202604009
Abstract:
Biological nitrogen removal in wastewater treatment plants （WWTPs） is commonly limited by insufficient influent carbon sources， thus making external carbon addition an important strategy for enhancing denitrification. However， conventional single carbon sources often fail to meet the metabolic demands of complex microbial communities， resulting in reduced nitrogen removal efficiency and stability. Composite carbon sources， by providing multiple electron donors， can improve metabolic cooperation among microorganisms， yet their underlying microbial mechanisms are still insufficiently understood. In this study， activated sludge from a municipal wastewater treatment plant was used to investigate the microbial mechanisms of composite carbon sources during denitrification. Batch denitrification experiments were conducted in combination with metagenomic and metatranscriptomic analyses to systematically characterize the microbial community structure and functional gene expression under composite carbon source conditions. The results showed that， compared with sodium acetate as the single carbon source， the composite carbon source system increased the denitrification rate from （6.822±0.141） mg/（L·h） to （8.370±0.186） mg/（L·h）， while reducing N2O accumulation by approximately 55%. Metagenomic analysis revealed that Ottowia， Rubrivivax， Thauera， and Zoogloea were the dominant denitrifying genera. Metatranscriptomic results further demonstrated that the composite carbon sources significantly upregulated the transcription of key denitrification genes， with nirS， norB， and nosZ increasing by 37.8%， 27.4%， and 48.6%， respectively. In addition， the composite carbon sources promoted complementary carbon metabolic strategies among different microbial communities， thereby enhancing the supply of electron donors and improving denitrification efficiency. These findings indicate that composite carbon sources synergistically enhance denitrification performance by regulating microbial community structure and functional gene expression， providing a theoretical basis for carbon source optimization in WWTPs.
Biological nitrogen removal in wastewater treatment plants （WWTPs） is commonly limited by insufficient influent carbon sources， thus making external carbon addition an important strategy for enhancing denitrification. However， conventional single carbon sources often fail to meet the metabolic demands of complex microbial communities， resulting in reduced nitrogen removal efficiency and stability. Composite carbon sources， by providing multiple electron donors， can improve metabolic cooperation among microorganisms， yet their underlying microbial mechanisms are still insufficiently understood. In this study， activated sludge from a municipal wastewater treatment plant was used to investigate the microbial mechanisms of composite carbon sources during denitrification. Batch denitrification experiments were conducted in combination with metagenomic and metatranscriptomic analyses to systematically characterize the microbial community structure and functional gene expression under composite carbon source conditions. The results showed that， compared with sodium acetate as the single carbon source， the composite carbon source system increased the denitrification rate from （6.822±0.141） mg/（L·h） to （8.370±0.186） mg/（L·h）， while reducing N2O accumulation by approximately 55%. Metagenomic analysis revealed that Ottowia， Rubrivivax， Thauera， and Zoogloea were the dominant denitrifying genera. Metatranscriptomic results further demonstrated that the composite carbon sources significantly upregulated the transcription of key denitrification genes， with nirS， norB， and nosZ increasing by 37.8%， 27.4%， and 48.6%， respectively. In addition， the composite carbon sources promoted complementary carbon metabolic strategies among different microbial communities， thereby enhancing the supply of electron donors and improving denitrification efficiency. These findings indicate that composite carbon sources synergistically enhance denitrification performance by regulating microbial community structure and functional gene expression， providing a theoretical basis for carbon source optimization in WWTPs.
2026, 44(4): 90-100.
doi: 10.13205/j.hjgc.202604010
Abstract:
The 1，2-propanediol in guar gum production wastewater tends to trigger propionate accumulation during traditional anaerobic treatment， leading to microbial activity inhibition. Microaerobic conditions can create a favorable environment for fermentative bacteria metabolism and promote the conversion of organic substrates. Biochar can facilitate the formation of anaerobic microbial aggregates and enhance the oxygen tolerance of anaerobic microorganisms. In this study， actual guar gum production wastewater was used as the research object， and a blank control group， an anaerobic group， and a microaerobic-biochar coupled （O2/BC） group were set up to investigate the operational efficiency of anaerobic digestion under the microaerobic-biochar coupled system. The results showed that through the regulation of micro-aeration ［0.2 mL/（g VS·d）］ and biochar dosage （15 g/L）， efficient wastewater treatment was achieved under mesophilic （37 ℃） conditions， with a COD removal efficiency reaching 90%， which was 10.6% higher than that of the anaerobic control group. The effluent COD concentration and propionate concentration were reduced to 3800 mg/L and 0.15 g/L， respectively， representing decreases of 49.6% and 98.4% compared to the anaerobic control group. The biogas production was 1.64 times that of the anaerobic control group， with the maximum methane concentration reaching 77.2%. Fourier transform infrared spectroscopy （FT-IR） revealed that the quantities of —OH， —CH2— and C—O functional groups on the surface of the sludge increased significantly， revealing the enhanced adsorption effect of biochar on microorganisms. Scanning electron microscopy （SEM） observations showed that the microaerobic-biochar coupled system formed dense microbial aggregates dominated by long bacilli， which were significantly different from traditional anaerobic sludge. The analysis of the microbial community composition revealed that the microaerobic-biochar coupled condition increased the abundance of Clostridium and Comamonas species， thereby modulating the propionate-to-acetate ratio and thus enhancing the efficiency of complex organic matter degradation.
The 1，2-propanediol in guar gum production wastewater tends to trigger propionate accumulation during traditional anaerobic treatment， leading to microbial activity inhibition. Microaerobic conditions can create a favorable environment for fermentative bacteria metabolism and promote the conversion of organic substrates. Biochar can facilitate the formation of anaerobic microbial aggregates and enhance the oxygen tolerance of anaerobic microorganisms. In this study， actual guar gum production wastewater was used as the research object， and a blank control group， an anaerobic group， and a microaerobic-biochar coupled （O2/BC） group were set up to investigate the operational efficiency of anaerobic digestion under the microaerobic-biochar coupled system. The results showed that through the regulation of micro-aeration ［0.2 mL/（g VS·d）］ and biochar dosage （15 g/L）， efficient wastewater treatment was achieved under mesophilic （37 ℃） conditions， with a COD removal efficiency reaching 90%， which was 10.6% higher than that of the anaerobic control group. The effluent COD concentration and propionate concentration were reduced to 3800 mg/L and 0.15 g/L， respectively， representing decreases of 49.6% and 98.4% compared to the anaerobic control group. The biogas production was 1.64 times that of the anaerobic control group， with the maximum methane concentration reaching 77.2%. Fourier transform infrared spectroscopy （FT-IR） revealed that the quantities of —OH， —CH2— and C—O functional groups on the surface of the sludge increased significantly， revealing the enhanced adsorption effect of biochar on microorganisms. Scanning electron microscopy （SEM） observations showed that the microaerobic-biochar coupled system formed dense microbial aggregates dominated by long bacilli， which were significantly different from traditional anaerobic sludge. The analysis of the microbial community composition revealed that the microaerobic-biochar coupled condition increased the abundance of Clostridium and Comamonas species， thereby modulating the propionate-to-acetate ratio and thus enhancing the efficiency of complex organic matter degradation.
2026, 44(4): 101-109.
doi: 10.13205/j.hjgc.202604011
Abstract:
With the increasingly severe global water scarcity， the utilization of reclaimed water has become an effective strategy to ensure water supply. Reverse osmosis （RO） technology is crucial for reclaimed water production， but membrane fouling severely constrains its efficiency. To address the spatial heterogeneity of RO membrane fouling after long-term operation in dual-membrane reclaimed water treatment processes， this study employs multi-dimensional characterization techniques to reveal fouling characteristics and microbial community differences at the inlet （RO1） and outlet （RO2） ends of RO membranes after 3.5 years of operation. Long-term monitoring shows that the microfiltration-reverse osmosis （MF-RO） coupled process stabilizes effluent turbidity below 0.1 NTU and conductivity under 400 μS/cm. However， the RO system's inlet pressure exhibits significant seasonal fluctuations （15%~22% amplitude in summer and winter）， which may be closely correlated to water viscosity changes induced by temperature variations. Simultaneously， while membrane surface fouling is predominantly characterized by calcium sulfate crystallization and rod-shaped microbial symbiotic structures， significant spatial heterogeneity exists in biofouling. The inlet end （RO1） features dense bio-inorganic composite fouling dominated by Proteobacteria （77.11%）， particularly Alphaproteobacteria （71.49%） and Microbacteriaceae. In contrast， the outlet end （RO2） shows reduced microbial abundance and altered community structure， likely driven by salinity gradients along the flow direction. This study elucidates the spatial heterogeneity of microbial fouling and community dynamics in long-term RO operation， providing critical theoretical and practical insights for optimizing RO management and developing targeted antifouling strategies in reclaimed water plants.
With the increasingly severe global water scarcity， the utilization of reclaimed water has become an effective strategy to ensure water supply. Reverse osmosis （RO） technology is crucial for reclaimed water production， but membrane fouling severely constrains its efficiency. To address the spatial heterogeneity of RO membrane fouling after long-term operation in dual-membrane reclaimed water treatment processes， this study employs multi-dimensional characterization techniques to reveal fouling characteristics and microbial community differences at the inlet （RO1） and outlet （RO2） ends of RO membranes after 3.5 years of operation. Long-term monitoring shows that the microfiltration-reverse osmosis （MF-RO） coupled process stabilizes effluent turbidity below 0.1 NTU and conductivity under 400 μS/cm. However， the RO system's inlet pressure exhibits significant seasonal fluctuations （15%~22% amplitude in summer and winter）， which may be closely correlated to water viscosity changes induced by temperature variations. Simultaneously， while membrane surface fouling is predominantly characterized by calcium sulfate crystallization and rod-shaped microbial symbiotic structures， significant spatial heterogeneity exists in biofouling. The inlet end （RO1） features dense bio-inorganic composite fouling dominated by Proteobacteria （77.11%）， particularly Alphaproteobacteria （71.49%） and Microbacteriaceae. In contrast， the outlet end （RO2） shows reduced microbial abundance and altered community structure， likely driven by salinity gradients along the flow direction. This study elucidates the spatial heterogeneity of microbial fouling and community dynamics in long-term RO operation， providing critical theoretical and practical insights for optimizing RO management and developing targeted antifouling strategies in reclaimed water plants.
2026, 44(4): 110-117.
doi: 10.13205/j.hjgc.202604012
Abstract:
The design daily treatment capacity of the newly built sewage treatment plant is 100000 m3/d. The inflow contains about 15% industrial wastewater， resulting in fluctuation coefficients in both water quality and quantity ranging from 1.2 to 1.5， with a proportion of difficulty degrading organic matter （measured as COD） greater than 35%， and a TN concentration of up to 55 mg/L. To ensure stable effluent quality and enhance the system’s resistance to shock loads， a modified Bardenpho process was adopted. This process integrates multi-point influent distribution and an additional post-anoxic and post-aerobic configuration， in combination with auxiliary units such as an equalization basin， a high-efficiency sedimentation tank， and a denitrifying deep-bed filter. These design features collectively aim to strengthen nitrogen and phosphorus removal efficiency as well as operational flexibility. During the commissioning and operational period， the process demonstrated excellent pollutant removal performance： the average removal efficiencies of COD， NH3-N， TN， and TP were 96.10%， 98.24%， 83.89%， and 98.29%， respectively. The corresponding effluent concentrations stabilized at 15.4 mg/L， 0.57 mg/L， 7.94 mg/L， and 0.12 mg/L， all of which consistently outperformed the Class 1A standard specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants （GB 18918—2002）. These findings confirm that the modified Bardenpho process is highly effective in treating wastewater with high nitrogen loads and refractory organic components， showing strong adaptability and system stability. Moreover， its configuration enhances carbon source utilization efficiency while reducing operational energy consumption. The design parameters and operational experiences from this project can serve as practical references for the planning， design， and optimization of large-scale municipal wastewater treatment plants， particularly those receiving a significant fraction of industrial wastewater.
The design daily treatment capacity of the newly built sewage treatment plant is 100000 m3/d. The inflow contains about 15% industrial wastewater， resulting in fluctuation coefficients in both water quality and quantity ranging from 1.2 to 1.5， with a proportion of difficulty degrading organic matter （measured as COD） greater than 35%， and a TN concentration of up to 55 mg/L. To ensure stable effluent quality and enhance the system’s resistance to shock loads， a modified Bardenpho process was adopted. This process integrates multi-point influent distribution and an additional post-anoxic and post-aerobic configuration， in combination with auxiliary units such as an equalization basin， a high-efficiency sedimentation tank， and a denitrifying deep-bed filter. These design features collectively aim to strengthen nitrogen and phosphorus removal efficiency as well as operational flexibility. During the commissioning and operational period， the process demonstrated excellent pollutant removal performance： the average removal efficiencies of COD， NH3-N， TN， and TP were 96.10%， 98.24%， 83.89%， and 98.29%， respectively. The corresponding effluent concentrations stabilized at 15.4 mg/L， 0.57 mg/L， 7.94 mg/L， and 0.12 mg/L， all of which consistently outperformed the Class 1A standard specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants （GB 18918—2002）. These findings confirm that the modified Bardenpho process is highly effective in treating wastewater with high nitrogen loads and refractory organic components， showing strong adaptability and system stability. Moreover， its configuration enhances carbon source utilization efficiency while reducing operational energy consumption. The design parameters and operational experiences from this project can serve as practical references for the planning， design， and optimization of large-scale municipal wastewater treatment plants， particularly those receiving a significant fraction of industrial wastewater.
2026, 44(4): 118-126.
doi: 10.13205/j.hjgc.202604013
Abstract:
Reclaimed water is an alternative water source that can help replenish natural lakes and rivers， alleviating issues such as water scarcity， flow disruptions， and poor water flow. Residual pollutants in reclaimed water could pose an ecological danger. Therefore， a pilot-scale hybrid vertical flow constructed wetland system， filled with manganese ore sand， quartz sand， and cobblestones， was constructed and operated for about 140 days. During this operation period， the efficiencies in removing nitrogen， phosphorus， and organic matter were studied. Also， the potential ecotoxicological effects exhibited by the purified reclaimed water were investigated. The practicality for the use of manganese ore sand as a functional filler was also assessed. The results demonstrated that after 2 to 3 months of operation， the removal efficiencies for ammonia and phosphate maintained above 90% and 80%， with their influent concentrations below 0.4 mg/L and 0.2 mg/L， respectively. With influent concentrations of 4 to 8 mg/L for nitrate and below 30 mg/L for oxygen-consuming organic matter （measured as COD）， their average concentration reductions remained below 1.0 mg/L and 5 mg/L， respectively. The manganese ore sand enhanced the decomposition and removal of residual organic matter， achieving 48% of reduction in 3D fluorescence intensity， a 38% decrease in UV254， and 70.8% in the removal of four target antibiotics. The reclaimed water after treatment exhibited no significant genotoxicity， its cell micronucleus rate approached that of tap water levels， and non-concentrated samples showed no acute biotoxicity. This study provides technical support for enhancing reclaimed water quality and controlling associated ecological risks.
Reclaimed water is an alternative water source that can help replenish natural lakes and rivers， alleviating issues such as water scarcity， flow disruptions， and poor water flow. Residual pollutants in reclaimed water could pose an ecological danger. Therefore， a pilot-scale hybrid vertical flow constructed wetland system， filled with manganese ore sand， quartz sand， and cobblestones， was constructed and operated for about 140 days. During this operation period， the efficiencies in removing nitrogen， phosphorus， and organic matter were studied. Also， the potential ecotoxicological effects exhibited by the purified reclaimed water were investigated. The practicality for the use of manganese ore sand as a functional filler was also assessed. The results demonstrated that after 2 to 3 months of operation， the removal efficiencies for ammonia and phosphate maintained above 90% and 80%， with their influent concentrations below 0.4 mg/L and 0.2 mg/L， respectively. With influent concentrations of 4 to 8 mg/L for nitrate and below 30 mg/L for oxygen-consuming organic matter （measured as COD）， their average concentration reductions remained below 1.0 mg/L and 5 mg/L， respectively. The manganese ore sand enhanced the decomposition and removal of residual organic matter， achieving 48% of reduction in 3D fluorescence intensity， a 38% decrease in UV254， and 70.8% in the removal of four target antibiotics. The reclaimed water after treatment exhibited no significant genotoxicity， its cell micronucleus rate approached that of tap water levels， and non-concentrated samples showed no acute biotoxicity. This study provides technical support for enhancing reclaimed water quality and controlling associated ecological risks.
2026, 44(4): 127-138.
doi: 10.13205/j.hjgc.202604014
Abstract:
To quantitatively investigate the volume distribution of ice slurry and the distribution of wall shear forces during the ice slurry pigging process， and explore the optimal process parameters， this study integrated the kinetic theory of granular flows （KTGF）， adopted the Euler-Euler method and the shear stress transport （SST） model to establish a computational fluid dynamics （CFD） model. The flow characteristics of the established model were verified using experimental data from relevant literature. After simulating 125 sets of different parameters for the ice slurry pigging process under common working conditions， the evaluation indicators were optimized， and the optimal flushing process parameters were determined. The results indicate that ice slurry with a high initial concentration can effectively clean both the upper and lower parts of the pipe wall， with the effective shear stress ratio of 60% concentration ice slurry reaching 77.39%. Ice slurry with larger particles exhibits significant upward movement behavior， and the non-uniformity of solid particle distribution increases with the increase in particle diameter. Flow velocity is the most critical factor affecting the shear stress exerted by ice slurry on the pipe wall； the cumulative shear stress increases and becomes more uniform with the increase in flow velocity， and the effective shear stress ratio at a flow velocity of 1.0 m/s is 83.16%. When the initial concentration of ice slurry is 50%， the particle size is 0.5 mm， and the flushing speed is 1.0 m/s， the average cumulative shear stress is 11.59 Pa·s， achieving the optimal flushing effect. This study can provide theoretical guidance for the operation of ice slurry pigging in water supply pipelines.
To quantitatively investigate the volume distribution of ice slurry and the distribution of wall shear forces during the ice slurry pigging process， and explore the optimal process parameters， this study integrated the kinetic theory of granular flows （KTGF）， adopted the Euler-Euler method and the shear stress transport （SST） model to establish a computational fluid dynamics （CFD） model. The flow characteristics of the established model were verified using experimental data from relevant literature. After simulating 125 sets of different parameters for the ice slurry pigging process under common working conditions， the evaluation indicators were optimized， and the optimal flushing process parameters were determined. The results indicate that ice slurry with a high initial concentration can effectively clean both the upper and lower parts of the pipe wall， with the effective shear stress ratio of 60% concentration ice slurry reaching 77.39%. Ice slurry with larger particles exhibits significant upward movement behavior， and the non-uniformity of solid particle distribution increases with the increase in particle diameter. Flow velocity is the most critical factor affecting the shear stress exerted by ice slurry on the pipe wall； the cumulative shear stress increases and becomes more uniform with the increase in flow velocity， and the effective shear stress ratio at a flow velocity of 1.0 m/s is 83.16%. When the initial concentration of ice slurry is 50%， the particle size is 0.5 mm， and the flushing speed is 1.0 m/s， the average cumulative shear stress is 11.59 Pa·s， achieving the optimal flushing effect. This study can provide theoretical guidance for the operation of ice slurry pigging in water supply pipelines.
2026, 44(4): 139-148.
doi: 10.13205/j.hjgc.202604015
Abstract:
Shale gas extraction produces a lot of solid waste in the process of drilling and exploitation， and oily sludge has been listed as hazardous waste. The complex composition of oily sludge and a variety of harmful compounds make the treatment of oily sludge difficult. Microemulsion is made by mixing a certain proportion of oil， water， salt， surfactant， and cosurfactant. The microemulsion method has advantages， such as low energy consumption， low cost， no heating needed， high oil removal efficiency， and can realize the ability to recover crude oil resources， etc.， so it is suitable for the in-situ oil removal for oily sludge. At present， it is necessary to explore a kind of composite microemulsion， which can improve the elution ability of microemulsion on oily sludge and have better recycling performance. In this paper， Na2SiO3 was proposed to be used to compound single microemulsion （SDS-Na2SiO3 type， AOS-Na2SiO3 type）， and its dispersion performance was utilized to form a composite microemulsion with higher oil removal efficiency. Firstly， by studying the phase change rule and oil removal efficiency of the microemulsion configured with a single surfactant， the preparation， phase change rule， and recycling frequency of the microemulsion configured with Na2SiO3 composite surfactant were studied. On this basis， SDS and AOS were used to prepare the composite microemulsion with sodium silicate （Na2SiO3）， and the phase variation of the microemulsion was studied. The removal rate of SDS microemulsion was 86.33%. The optimal formula was SDS∶ alcohol∶ NaCl=2.72%∶ 13.21%∶ 2.17% （mass ratio）. The removal rate of AOS microemulsion was 87.45%， and the optimal formula was SDS∶ Alcohol∶ NaCl=2.72%∶ 15.41%∶ 2.17% （mass ratio）. The effect of SDS microemulsion on eluting oily sludge was slightly lower than that of AOS microemulsion， but SDS microemulsion had a better effect on preparation and phase stability. The salt resistance of AOS-Na2SiO3 composite microemulsion was better than that of SDS-Na2SiO3 composite microemulsion， but the alcohol resistance was opposite. The oil removal efficiency of SDS-Na2SiO3 composite microemulsion was 92.47%， better than that of the single microemulsion. On the basis of reaching the national secondary utilization standard， the compound microemulsion can be reused for 5 times. This study，provides a new idea and technical support for in-situ treatment of oily sludge.
Shale gas extraction produces a lot of solid waste in the process of drilling and exploitation， and oily sludge has been listed as hazardous waste. The complex composition of oily sludge and a variety of harmful compounds make the treatment of oily sludge difficult. Microemulsion is made by mixing a certain proportion of oil， water， salt， surfactant， and cosurfactant. The microemulsion method has advantages， such as low energy consumption， low cost， no heating needed， high oil removal efficiency， and can realize the ability to recover crude oil resources， etc.， so it is suitable for the in-situ oil removal for oily sludge. At present， it is necessary to explore a kind of composite microemulsion， which can improve the elution ability of microemulsion on oily sludge and have better recycling performance. In this paper， Na2SiO3 was proposed to be used to compound single microemulsion （SDS-Na2SiO3 type， AOS-Na2SiO3 type）， and its dispersion performance was utilized to form a composite microemulsion with higher oil removal efficiency. Firstly， by studying the phase change rule and oil removal efficiency of the microemulsion configured with a single surfactant， the preparation， phase change rule， and recycling frequency of the microemulsion configured with Na2SiO3 composite surfactant were studied. On this basis， SDS and AOS were used to prepare the composite microemulsion with sodium silicate （Na2SiO3）， and the phase variation of the microemulsion was studied. The removal rate of SDS microemulsion was 86.33%. The optimal formula was SDS∶ alcohol∶ NaCl=2.72%∶ 13.21%∶ 2.17% （mass ratio）. The removal rate of AOS microemulsion was 87.45%， and the optimal formula was SDS∶ Alcohol∶ NaCl=2.72%∶ 15.41%∶ 2.17% （mass ratio）. The effect of SDS microemulsion on eluting oily sludge was slightly lower than that of AOS microemulsion， but SDS microemulsion had a better effect on preparation and phase stability. The salt resistance of AOS-Na2SiO3 composite microemulsion was better than that of SDS-Na2SiO3 composite microemulsion， but the alcohol resistance was opposite. The oil removal efficiency of SDS-Na2SiO3 composite microemulsion was 92.47%， better than that of the single microemulsion. On the basis of reaching the national secondary utilization standard， the compound microemulsion can be reused for 5 times. This study，provides a new idea and technical support for in-situ treatment of oily sludge.
2026, 44(4): 149-156.
doi: 10.13205/j.hjgc.202604016
Abstract:
River and lake health assessment is an important technical means to evaluate the health status of rivers and lakes， scientifically analyze River and lake problems， and strengthen the implementation of the river and lake head system. It is an important reference for the river and lake head to organize and lead the management and protection of rivers and lakes. Based on the Guidelines for River and Lake Health Assessment （Trial） and the characteristics and actual basin conditions of the lower Yellow River in Henan， this study determined the river health evaluation index system of the lower Yellow River in Henan. By collecting and reviewing relevant basic data， organizing and carrying out special investigations and monitoring， the health status of the river reach in 2020 was evaluated from the four levels of "basin"， "water"， biology， and social service function. The final score was 83.4 points， the health level was "health"， and the four criteria levels were 73.7 points， 95.0 points， 62.1 points， and 95.5 points， respectively. The evaluation results indicate that the main problems existing in the lower Yellow River in Henan are low aquatic biodiversity， general shoreline conditions， water supply security pressure， etc. Accordingly， measures for river governance and protection are put forward， such as strengthening ecological protection， improving river regulation works， strengthening shoreline management， and improving the facilities for water diversion， etc.
River and lake health assessment is an important technical means to evaluate the health status of rivers and lakes， scientifically analyze River and lake problems， and strengthen the implementation of the river and lake head system. It is an important reference for the river and lake head to organize and lead the management and protection of rivers and lakes. Based on the Guidelines for River and Lake Health Assessment （Trial） and the characteristics and actual basin conditions of the lower Yellow River in Henan， this study determined the river health evaluation index system of the lower Yellow River in Henan. By collecting and reviewing relevant basic data， organizing and carrying out special investigations and monitoring， the health status of the river reach in 2020 was evaluated from the four levels of "basin"， "water"， biology， and social service function. The final score was 83.4 points， the health level was "health"， and the four criteria levels were 73.7 points， 95.0 points， 62.1 points， and 95.5 points， respectively. The evaluation results indicate that the main problems existing in the lower Yellow River in Henan are low aquatic biodiversity， general shoreline conditions， water supply security pressure， etc. Accordingly， measures for river governance and protection are put forward， such as strengthening ecological protection， improving river regulation works， strengthening shoreline management， and improving the facilities for water diversion， etc.
2026, 44(4): 157-168.
doi: 10.13205/j.hjgc.202604017
Abstract:
The Shule River Basin is a typical inland river basin in arid areas， and its water yield is crucial for regional ecological security and sustainable development. This study integrated the FLUS and InVEST models to simulate the basin's water yield in 2030 and 2050 under three climate scenarios （SSP119， SSP245， and SSP585）. Geographical detectors were further applied to quantify the driving mechanisms of natural and human factors. The key findings are as follows： 1） Land use in the basin is dominated by desert. Under the SSP119 scenario， the desert area is projected to decrease by 0.69% by 2050， whereas it is projected to increase sharply by 5.7% under the SSP585 scenario. 2） The spatial distribution of water yield exhibits a pattern of higher values in the south and lower values in the north， with high-yield areas concentrated in glacier-covered areas and high-altitude mountainous regions. The most significant increase in water yield occurs under the SSP119 scenario， while the SSP585 scenario shows only a minimal increase due to extreme climate conditions. 3） Precipitation and DEM are identified as the core driving factors governing the spatial distribution of water yield. The interaction between land-use type and precipitation has the strongest influence， indicating that artificial changes in land use can significantly regulate water yield. This research provides a multi-scenario framework to guide water resource management and ecological governance for inland river basins of arid areas.
The Shule River Basin is a typical inland river basin in arid areas， and its water yield is crucial for regional ecological security and sustainable development. This study integrated the FLUS and InVEST models to simulate the basin's water yield in 2030 and 2050 under three climate scenarios （SSP119， SSP245， and SSP585）. Geographical detectors were further applied to quantify the driving mechanisms of natural and human factors. The key findings are as follows： 1） Land use in the basin is dominated by desert. Under the SSP119 scenario， the desert area is projected to decrease by 0.69% by 2050， whereas it is projected to increase sharply by 5.7% under the SSP585 scenario. 2） The spatial distribution of water yield exhibits a pattern of higher values in the south and lower values in the north， with high-yield areas concentrated in glacier-covered areas and high-altitude mountainous regions. The most significant increase in water yield occurs under the SSP119 scenario， while the SSP585 scenario shows only a minimal increase due to extreme climate conditions. 3） Precipitation and DEM are identified as the core driving factors governing the spatial distribution of water yield. The interaction between land-use type and precipitation has the strongest influence， indicating that artificial changes in land use can significantly regulate water yield. This research provides a multi-scenario framework to guide water resource management and ecological governance for inland river basins of arid areas.
2026, 44(4): 169-180.
doi: 10.13205/j.hjgc.202604018
Abstract:
To address the issues of high air volume and unorganized emissions of waste gas in the semi-steel vulcanization production lines， a combined approach of experimental testing and numerical simulation was employed to study the diffusion characteristics of VOCs-containing waste gas and air volume of the system. The structure of the semi-enclosed hood was optimized， and the pipe diameter was adjusted to achieve negative pressure balance in the collection system， thereby enabling efficient waste gas collection. The results showed that the toluene concentration distribution obtained from numerical simulation was largely consistent with the experimental test results. The hood inlet wind speeds at various collection hoods on the existing vulcanization production line ranged from 0.04 m/s to 0.2 m/s， indicating uneven wind speed distribution. Under calm wind condition， the toluene diffusion characteristics inside the enclosed hood and the semi-enclosed hood were similar， with toluene concentrations of 248 mg/m3 in the enclosed hood， and 115 mg/m3 in the semi-enclosed hood， and toluene waste gas deposition was observed in the trench. By optimizing the structure of the semi-enclosed hood， with a designed air volume of 1.0×105 m3/h， the average hood inlet wind speed was 0.35 m/s， but the wind speed distribution at the hood inlets remained uneven. Gradual diameter reduction pipes were added to the branches， and the pipe diameters were adjusted. After optimization， the total air volume deviation for branch Ⅰ was -0.44%， and for branch Ⅱ， it was 0.38%. The air volume deviation at each hood inlet was less than 10%， achieving negative pressure balance in the waste gas collection system， which allows for effective waste gas collection and improves the labor hygiene conditions in the workshop. This study can provide industrial parameter references for effective collection of waste gas in semi-steel vulcanization production lines.
To address the issues of high air volume and unorganized emissions of waste gas in the semi-steel vulcanization production lines， a combined approach of experimental testing and numerical simulation was employed to study the diffusion characteristics of VOCs-containing waste gas and air volume of the system. The structure of the semi-enclosed hood was optimized， and the pipe diameter was adjusted to achieve negative pressure balance in the collection system， thereby enabling efficient waste gas collection. The results showed that the toluene concentration distribution obtained from numerical simulation was largely consistent with the experimental test results. The hood inlet wind speeds at various collection hoods on the existing vulcanization production line ranged from 0.04 m/s to 0.2 m/s， indicating uneven wind speed distribution. Under calm wind condition， the toluene diffusion characteristics inside the enclosed hood and the semi-enclosed hood were similar， with toluene concentrations of 248 mg/m3 in the enclosed hood， and 115 mg/m3 in the semi-enclosed hood， and toluene waste gas deposition was observed in the trench. By optimizing the structure of the semi-enclosed hood， with a designed air volume of 1.0×105 m3/h， the average hood inlet wind speed was 0.35 m/s， but the wind speed distribution at the hood inlets remained uneven. Gradual diameter reduction pipes were added to the branches， and the pipe diameters were adjusted. After optimization， the total air volume deviation for branch Ⅰ was -0.44%， and for branch Ⅱ， it was 0.38%. The air volume deviation at each hood inlet was less than 10%， achieving negative pressure balance in the waste gas collection system， which allows for effective waste gas collection and improves the labor hygiene conditions in the workshop. This study can provide industrial parameter references for effective collection of waste gas in semi-steel vulcanization production lines.
2026, 44(4): 181-188.
doi: 10.13205/j.hjgc.202604019
Abstract:
Addressing the complex pollution control challenge of fine particulate matter and volatile organic compounds （VOCs） in catering fumes， this paper constructed a two-stage ESP system consisting of a sawtooth-rod electrode structure （preloading unit） and a plate-plate electrode structure （i.e.， particle collection unit）， and conducted systematic research on the gas-solid mixture components of the simulated catering fumes， using potassium chloride particles and toluene gas. The experimental results showed that when the voltage of the sawtooth-rod charged electrode was +12 kV and the voltage of the plate-plate dust collection electrode was -8.5 kV， the ozone concentration was 176.9 mg/m3， and the collection efficiency of fine particles with a particle size <0.3 μm reached 91%， while the total collection efficiency of particles exceeded 98%； the existance of particles can accelerate the removal of toluene， and after injecting particles into the system， the degradation efficiency of toluene increased from 29.2% to 53.1%. The research results can provide technical support for the collaborative treatment of compound pollution in catering fumes.
Addressing the complex pollution control challenge of fine particulate matter and volatile organic compounds （VOCs） in catering fumes， this paper constructed a two-stage ESP system consisting of a sawtooth-rod electrode structure （preloading unit） and a plate-plate electrode structure （i.e.， particle collection unit）， and conducted systematic research on the gas-solid mixture components of the simulated catering fumes， using potassium chloride particles and toluene gas. The experimental results showed that when the voltage of the sawtooth-rod charged electrode was +12 kV and the voltage of the plate-plate dust collection electrode was -8.5 kV， the ozone concentration was 176.9 mg/m3， and the collection efficiency of fine particles with a particle size <0.3 μm reached 91%， while the total collection efficiency of particles exceeded 98%； the existance of particles can accelerate the removal of toluene， and after injecting particles into the system， the degradation efficiency of toluene increased from 29.2% to 53.1%. The research results can provide technical support for the collaborative treatment of compound pollution in catering fumes.
2026, 44(4): 189-199.
doi: 10.13205/j.hjgc.202604020
Abstract:
Source reduction of volatile organic compounds （VOCs） from industrial emissions is a core task for air quality improvement during the 15th Five-Year Plan period of China. Supercritical carbon dioxide （ScCO2） spraying technology emerges as a cutting-edge VOCs abatement approach， as it not only reduces VOCs emissions but also minimizes coating consumption. However， empirical research on the enhancement of coating efficiency and VOCs emission reduction effects at the demonstration application scale remains scarce. In this study， three solvent-based coating systems widely adopted in Chinese industrial enterprises were selected， namely wooden furniture-polyurethane， wooden furniture-acrylic， and metal parts-fluorocarbon. A calculation method for ScCO2 spraying efficiency and VOCs emission reduction rate was established， and its emission reduction performance was systematically measured and analyzed. The results indicated that compared with high-pressure airless spraying， the average coating efficiency improvement rates of ScCO2 spraying at spray distances of 60 cm and 40 cm across the three demonstration scenarios were （30.62±8.75）% and （31.74±12.83）%， respectively. Correspondingly， the average VOCs emission reduction rates achieved by ScCO2 spraying under the same conditions were （62.10±1.59）% （60 cm） and （53.73±11.78）% （40 cm）. This study confirms that ScCO2 spraying can achieve significant reductions in VOCs and solvent emissions in the coating processes of wooden furniture and metal parts， providing empirical support for its industrial promotion.
Source reduction of volatile organic compounds （VOCs） from industrial emissions is a core task for air quality improvement during the 15th Five-Year Plan period of China. Supercritical carbon dioxide （ScCO2） spraying technology emerges as a cutting-edge VOCs abatement approach， as it not only reduces VOCs emissions but also minimizes coating consumption. However， empirical research on the enhancement of coating efficiency and VOCs emission reduction effects at the demonstration application scale remains scarce. In this study， three solvent-based coating systems widely adopted in Chinese industrial enterprises were selected， namely wooden furniture-polyurethane， wooden furniture-acrylic， and metal parts-fluorocarbon. A calculation method for ScCO2 spraying efficiency and VOCs emission reduction rate was established， and its emission reduction performance was systematically measured and analyzed. The results indicated that compared with high-pressure airless spraying， the average coating efficiency improvement rates of ScCO2 spraying at spray distances of 60 cm and 40 cm across the three demonstration scenarios were （30.62±8.75）% and （31.74±12.83）%， respectively. Correspondingly， the average VOCs emission reduction rates achieved by ScCO2 spraying under the same conditions were （62.10±1.59）% （60 cm） and （53.73±11.78）% （40 cm）. This study confirms that ScCO2 spraying can achieve significant reductions in VOCs and solvent emissions in the coating processes of wooden furniture and metal parts， providing empirical support for its industrial promotion.
2026, 44(4): 200-209.
doi: 10.13205/j.hjgc.202604021
Abstract:
In this paper， a novel pulse cleaning blowpipe was independently designed. Based on fluid mechanics principles， the blowpipe was configured with an inner diameter of 40 mm and a total length of 660 mm. 6 mm diameter orifices were drilled at 110-mm intervals along the circumferential direction of the pipe； these orifices serve as gas outlets， directing the blown gas to act directly on the inner wall of the filter cartridge. The cleaning process was achieved through the combined action of gas flow impact force and cleaning pressure. Experimental design was based on computational fluid dynamics （CFD） simulations， with tests conducted under a pulse pressure of 0.3 MPa. Pressure contour diagrams of cross-sections at different time intervals and those at varying blowing distances at the same time point were monitored. On this basis， the total pressure peaks， dynamic pressure peaks， and static pressure peaks were measured separately at the front orifices， inter-front-orifice regions， side orifices， and inter-side-orifice regions of the blowpipe. Pressure variations of dynamic and static pressures throughout the entire cleaning process were analyzed using the pressure contour diagrams. The results indicate that the system reaches a stable state at 60 ms， significantly shortening the cleaning cycle. It was concluded that the front orifices exhibit the highest pressure peaks， while the inter-side-orifice regions show the lowest pressure peaks. However， the gas blowing uniformity at the inter-side-orifice regions is significantly superior to that at the front orifices.
In this paper， a novel pulse cleaning blowpipe was independently designed. Based on fluid mechanics principles， the blowpipe was configured with an inner diameter of 40 mm and a total length of 660 mm. 6 mm diameter orifices were drilled at 110-mm intervals along the circumferential direction of the pipe； these orifices serve as gas outlets， directing the blown gas to act directly on the inner wall of the filter cartridge. The cleaning process was achieved through the combined action of gas flow impact force and cleaning pressure. Experimental design was based on computational fluid dynamics （CFD） simulations， with tests conducted under a pulse pressure of 0.3 MPa. Pressure contour diagrams of cross-sections at different time intervals and those at varying blowing distances at the same time point were monitored. On this basis， the total pressure peaks， dynamic pressure peaks， and static pressure peaks were measured separately at the front orifices， inter-front-orifice regions， side orifices， and inter-side-orifice regions of the blowpipe. Pressure variations of dynamic and static pressures throughout the entire cleaning process were analyzed using the pressure contour diagrams. The results indicate that the system reaches a stable state at 60 ms， significantly shortening the cleaning cycle. It was concluded that the front orifices exhibit the highest pressure peaks， while the inter-side-orifice regions show the lowest pressure peaks. However， the gas blowing uniformity at the inter-side-orifice regions is significantly superior to that at the front orifices.
2026, 44(4): 210-218.
doi: 10.13205/j.hjgc.202604022
Abstract:
The resource utilization of food waste contributes to reducing environmental pollution， drives the cycling of nutrients and the development of biomass energy， promotes the growth of the resource recycling industry， and achieves a win-win outcome on both the environment and the economy. This study evaluated the resource recovery performance and environmental impacts of producing carbon sources for wastewater treatment through the hydrolysis and acidification of food waste. This innovative technology was compared with two conventional alternatives： anaerobic fermentation and incineration. The results showed that among the three technologies， the resource recycling efficiency of hydrolysis for carbon source production ranked in the middle， while its environmental benefits were superior to those of incineration and anaerobic fermentation technologies. The hydrolysis process did not produce additional wastewater requiring treatment. Moreover， its greenhouse gas emissions and solid waste generation intensity were relatively low， at -40.7 kg CO2-eq/t and 9.3%， respectively. Carbon sources derived from food waste can replace commercial alternatives， thereby reducing wastewater treatment costs and promoting synergies between pollution reduction and carbon mitigation. Sensitivity analysis revealed that the water content in food waste can significantly influence the generation of solid impurities and the energy recovery efficiency of the hydrolysis technology. In regions with high food waste generation and demand for carbon sources， hydrolysis technology is recommended to facilitate large-scale synergistic treatment of wastewater and food waste.
The resource utilization of food waste contributes to reducing environmental pollution， drives the cycling of nutrients and the development of biomass energy， promotes the growth of the resource recycling industry， and achieves a win-win outcome on both the environment and the economy. This study evaluated the resource recovery performance and environmental impacts of producing carbon sources for wastewater treatment through the hydrolysis and acidification of food waste. This innovative technology was compared with two conventional alternatives： anaerobic fermentation and incineration. The results showed that among the three technologies， the resource recycling efficiency of hydrolysis for carbon source production ranked in the middle， while its environmental benefits were superior to those of incineration and anaerobic fermentation technologies. The hydrolysis process did not produce additional wastewater requiring treatment. Moreover， its greenhouse gas emissions and solid waste generation intensity were relatively low， at -40.7 kg CO2-eq/t and 9.3%， respectively. Carbon sources derived from food waste can replace commercial alternatives， thereby reducing wastewater treatment costs and promoting synergies between pollution reduction and carbon mitigation. Sensitivity analysis revealed that the water content in food waste can significantly influence the generation of solid impurities and the energy recovery efficiency of the hydrolysis technology. In regions with high food waste generation and demand for carbon sources， hydrolysis technology is recommended to facilitate large-scale synergistic treatment of wastewater and food waste.
2026, 44(4): 219-228.
doi: 10.13205/j.hjgc.202604023
Abstract:
Fly ash， with its high content of silicon and aluminum， has become a hot topic for synthesizing high-value-added zeolites and absorbing harmful gases. However， current research primarily focuses on using fly ash-based zeolites to adsorb high-concentration gas pollutants， with few studies addressing low-concentration gas pollutants， especially acidic gases. In this study， the adsorption performance of fly ash-based zeolites （A- and H-type） for low-concentration acidic gases （SO2， CO2， and NO） in flue gas was investigated. The saturated adsorption capacities of A- and H-type zeolites for SO2， CO2， and NO were evaluated using a fixed bed infrared combined test platform under low-concentration conditions （1000 mg/m3）， for different zeolite types， and at varying temperatures. The adsorption mechanisms of SO2， CO2， and NO by A- and H-type zeolites were studied using in-situ DRIFTS spectroscopy combined with kinetic modeling. The experimental results showed that the specific surface area and pore structure of the zeolites were the main factors affecting their adsorption performance. The adsorption energies of A-type zeolite for SO2， CO2， and NO were -5.11 kJ/mol， -4.07 kJ/mol， and -1.41 kJ/mol， respectively， indicating a significantly stronger adsorption capacity compared to H-type zeolite. The T-O （T=Si/Al ） groups on the surface of A- and H-type zeolites were identified as the key active sites for acid gas adsorption， with A-type zeolite possessing a larger specific surface area and more silanol active sites. The experimental results provide a theoretical basis for the adsorption of acidic gases by fly ash-based zeolites.
Fly ash， with its high content of silicon and aluminum， has become a hot topic for synthesizing high-value-added zeolites and absorbing harmful gases. However， current research primarily focuses on using fly ash-based zeolites to adsorb high-concentration gas pollutants， with few studies addressing low-concentration gas pollutants， especially acidic gases. In this study， the adsorption performance of fly ash-based zeolites （A- and H-type） for low-concentration acidic gases （SO2， CO2， and NO） in flue gas was investigated. The saturated adsorption capacities of A- and H-type zeolites for SO2， CO2， and NO were evaluated using a fixed bed infrared combined test platform under low-concentration conditions （1000 mg/m3）， for different zeolite types， and at varying temperatures. The adsorption mechanisms of SO2， CO2， and NO by A- and H-type zeolites were studied using in-situ DRIFTS spectroscopy combined with kinetic modeling. The experimental results showed that the specific surface area and pore structure of the zeolites were the main factors affecting their adsorption performance. The adsorption energies of A-type zeolite for SO2， CO2， and NO were -5.11 kJ/mol， -4.07 kJ/mol， and -1.41 kJ/mol， respectively， indicating a significantly stronger adsorption capacity compared to H-type zeolite. The T-O （T=Si/Al ） groups on the surface of A- and H-type zeolites were identified as the key active sites for acid gas adsorption， with A-type zeolite possessing a larger specific surface area and more silanol active sites. The experimental results provide a theoretical basis for the adsorption of acidic gases by fly ash-based zeolites.
2026, 44(4): 229-239.
doi: 10.13205/j.hjgc.202604024
Abstract:
In order to enhance sludge dewatering efficiency， an MnFe2O4/BC/PMS system was constructed for sludge disintegration. Through single-factor and multi-factor experiments， the effects of MnFe2O4/BC dosage， PMS dosage， and reaction time on the sludge dewatering efficiency were investigated. The optimal process parameters for sludge dewatering and the primary-secondary relationship of environmental factors were clarified. By identifying the active substances in the MnFe2O4/BC/PMS system， the main free radicals released by MnFe2O4/BC-activated PMS to disintegrate sludge and the main pathways for EPS disintegration were determined. The results showed that the influence of environmental factors on the sludge moisture content （Wc） and total organic carbon （TOC） content followed the order of MnFe2O4/BC > PMS > reaction time. The order of influence of factor interactions on sludge dewatering performance was MnFe2O4/BC and PMS > PMS and reaction time > MnFe2O4/BC and reaction time. When the MnFe2O4/BC dosage was 132.99 mg/g DS， the PMS dosage was 421.80 mg/g DS， and the reaction time was 18 min， the sludge dewatering efficiency was the best， with the Wc and TOC content reaching 45.8% and 489.2 mg/L， respectively. The ·OH and SO4-· released from MnFe2O4/BC-activated PMS oxidized the protein main chain， leading to peptide chain breakage. This primarily reduced the protein content in the sludge from 174.6 mg/L to 75.7 mg/L， and especially in TB-EPS from 91.8 mg/L to 36.3 mg/L， thereby decreasing the hydrophilicity of EPS and improving sludge dewatering efficiency.
In order to enhance sludge dewatering efficiency， an MnFe2O4/BC/PMS system was constructed for sludge disintegration. Through single-factor and multi-factor experiments， the effects of MnFe2O4/BC dosage， PMS dosage， and reaction time on the sludge dewatering efficiency were investigated. The optimal process parameters for sludge dewatering and the primary-secondary relationship of environmental factors were clarified. By identifying the active substances in the MnFe2O4/BC/PMS system， the main free radicals released by MnFe2O4/BC-activated PMS to disintegrate sludge and the main pathways for EPS disintegration were determined. The results showed that the influence of environmental factors on the sludge moisture content （Wc） and total organic carbon （TOC） content followed the order of MnFe2O4/BC > PMS > reaction time. The order of influence of factor interactions on sludge dewatering performance was MnFe2O4/BC and PMS > PMS and reaction time > MnFe2O4/BC and reaction time. When the MnFe2O4/BC dosage was 132.99 mg/g DS， the PMS dosage was 421.80 mg/g DS， and the reaction time was 18 min， the sludge dewatering efficiency was the best， with the Wc and TOC content reaching 45.8% and 489.2 mg/L， respectively. The ·OH and SO4-· released from MnFe2O4/BC-activated PMS oxidized the protein main chain， leading to peptide chain breakage. This primarily reduced the protein content in the sludge from 174.6 mg/L to 75.7 mg/L， and especially in TB-EPS from 91.8 mg/L to 36.3 mg/L， thereby decreasing the hydrophilicity of EPS and improving sludge dewatering efficiency.
2026, 44(4): 240-256.
doi: 10.13205/j.hjgc.202604025
Abstract:
To meet the minute-level early-warning requirements for odor and multi-pollutant emissions at waste treatment facilities， this study proposed a multivariate short-term time-series prediction framework applicable to multi-tier scenarios covering source and boundary points （i.e.， workshops and plant boundaries）. Based on continuous online monitoring data with a 5-second resolution， a long short-term memory （LSTM） model using a sliding-window and recursive multi-step prediction strategy was constructed to jointly model odor concentration （OU） and pollutants including VOCs， NH3， H2S， and CH3SH （mg/m3）. An evaluation protocol aligned with environmental supervision practice was established， incorporating mean absolute error （MAE）， root mean square error （RMSE）， goodness-of-fit （R²）， skill scores （SS） relative to a persistence baseline， and threshold-based error stratification to characterize uncertainty during peak emission periods. The results showed that at workshop monitoring sites with relatively stable operating conditions， VOCs， NH3， H2S， and CH3SH exhibited a high goodness of fit and low prediction errors. In contrast， at boundary sites affected by plume arrival delays and diffusion-dilution non-stationarity， OU and VOCs displayed significantly amplified errors during peak episodes， and the skill score advantage over the baseline became unstable at certain sites. Stratified analysis consistently revealed that non-peak periods outperformed peak periods， indicating that event-driven fluctuations were the main sources of error. Accordingly， this study suggested incorporating exogenous variables such as wind speed and direction， ventilation and gate access control， and operational rhythms， along with peak-sensitive loss functions， into the model to enhance its capacity to characterize and provide early warnings for transient emission pulses. Overall， this study established a reusable methodological baseline and evaluation paradigm for minute-scale multi-pollutant prediction， providing quantitative support for the operational management and source-to-boundary coordinated control of waste treatment facilities.
To meet the minute-level early-warning requirements for odor and multi-pollutant emissions at waste treatment facilities， this study proposed a multivariate short-term time-series prediction framework applicable to multi-tier scenarios covering source and boundary points （i.e.， workshops and plant boundaries）. Based on continuous online monitoring data with a 5-second resolution， a long short-term memory （LSTM） model using a sliding-window and recursive multi-step prediction strategy was constructed to jointly model odor concentration （OU） and pollutants including VOCs， NH3， H2S， and CH3SH （mg/m3）. An evaluation protocol aligned with environmental supervision practice was established， incorporating mean absolute error （MAE）， root mean square error （RMSE）， goodness-of-fit （R²）， skill scores （SS） relative to a persistence baseline， and threshold-based error stratification to characterize uncertainty during peak emission periods. The results showed that at workshop monitoring sites with relatively stable operating conditions， VOCs， NH3， H2S， and CH3SH exhibited a high goodness of fit and low prediction errors. In contrast， at boundary sites affected by plume arrival delays and diffusion-dilution non-stationarity， OU and VOCs displayed significantly amplified errors during peak episodes， and the skill score advantage over the baseline became unstable at certain sites. Stratified analysis consistently revealed that non-peak periods outperformed peak periods， indicating that event-driven fluctuations were the main sources of error. Accordingly， this study suggested incorporating exogenous variables such as wind speed and direction， ventilation and gate access control， and operational rhythms， along with peak-sensitive loss functions， into the model to enhance its capacity to characterize and provide early warnings for transient emission pulses. Overall， this study established a reusable methodological baseline and evaluation paradigm for minute-scale multi-pollutant prediction， providing quantitative support for the operational management and source-to-boundary coordinated control of waste treatment facilities.
2026, 44(4): 257-269.
doi: 10.13205/j.hjgc.202604026
Abstract:
Polycyclic aromatic hydrocarbons （PAHs）， as a typical class of persistent organic pollutants （POPs）， are widely present in soils and pose a serious threat to ecosystems and human health. In this study， MIL-88A（Fe） catalyst was prepared using a hydrothermal solvent method and applied to the photocatalytic process of phenanthrene-pyrene （PHE-PYR） composite contaminated soil to investigate the adsorption-photocatalytic synergistic effect of MIL-88A（Fe） catalyst. The results showed that the adsorption behavior of MIL-88A（Fe） catalyst on PHE-PYR composite pollutants was dominated by physical adsorption and surface monolayer adsorption， with the maximum adsorption amount reaching 97.25 mg/kg， and the stronger adsorption capacity increased the concentration of pollutants near the active sites on the catalyst surface， which accelerated the pollutants' photocatalytic degradation efficiency； The adsorption-photocatalytic degradation of PHE-PYR composite pollutants in soil reached 79.20% at 3% catalyst dosage， 40% soil water content， 60 min light time， initial pollutant concentration of 200 mg/kg， and initial soil acidity. To further explore the photocatalytic reaction mechanism， the photoelectrochemical characterization results showed that the MIL-88A（Fe） catalyst had a remarkable photoresponsive ability in the visible wavelength range， and the narrow forbidden band width （3.04 eV） and energy band structure were conducive to the effective separation of photogenerated electron-hole pairs， which facilitated the photocatalytic reaction； and the results of the quenching experiments showed that the superoxide radicals （·O2 -
Polycyclic aromatic hydrocarbons （PAHs）， as a typical class of persistent organic pollutants （POPs）， are widely present in soils and pose a serious threat to ecosystems and human health. In this study， MIL-88A（Fe） catalyst was prepared using a hydrothermal solvent method and applied to the photocatalytic process of phenanthrene-pyrene （PHE-PYR） composite contaminated soil to investigate the adsorption-photocatalytic synergistic effect of MIL-88A（Fe） catalyst. The results showed that the adsorption behavior of MIL-88A（Fe） catalyst on PHE-PYR composite pollutants was dominated by physical adsorption and surface monolayer adsorption， with the maximum adsorption amount reaching 97.25 mg/kg， and the stronger adsorption capacity increased the concentration of pollutants near the active sites on the catalyst surface， which accelerated the pollutants' photocatalytic degradation efficiency； The adsorption-photocatalytic degradation of PHE-PYR composite pollutants in soil reached 79.20% at 3% catalyst dosage， 40% soil water content， 60 min light time， initial pollutant concentration of 200 mg/kg， and initial soil acidity. To further explore the photocatalytic reaction mechanism， the photoelectrochemical characterization results showed that the MIL-88A（Fe） catalyst had a remarkable photoresponsive ability in the visible wavelength range， and the narrow forbidden band width （3.04 eV） and energy band structure were conducive to the effective separation of photogenerated electron-hole pairs， which facilitated the photocatalytic reaction； and the results of the quenching experiments showed that the superoxide radicals （·O
2026, 44(4): 270-277.
doi: 10.13205/j.hjgc.202604027
Abstract:
Magnesia production processes generate carbon monoxide （CO） emissions； however， publicly available measured data on CO emission factors for these processes remain scarce， which constrains the accuracy of emission accounting and mitigation assessment in the industry. To address the lack of basic data on CO emissions from typical magnesia production processes， this study selected three representative magnesia-producing enterprises in Anshan， Liaoning Province， China， covering three typical technological routes： the two-stage calcination process （“light burning-briquetting-shaft kiln dead burning”）， the “suspension calcination-dead burning sintering” process， and the electric arc furnace melting process. Under the condition that enterprises were not equipped with online CO monitoring modules， an estimation approach coupling manual measurements with conventional indicators from the Continuous Emission Monitoring System （CEMS） was developed. By establishing characteristic concentration ratios between CO and nitrogen oxides （NO x ） or particulate matter （PM）， and combining them with annual CEMS monitoring data， product-level CO emission factors were calculated. The results showed that the CO emission factors for the two-stage calcination process， the suspension calcination–dead burning sintering process， and the electric arc furnace melting process were 5.35， 5.18， and 1.40 kg/t， respectively， among which the emission level of the electric arc furnace melting process was significantly lower than that of sintering-based processes. This study provides enterprise-level measured CO parameters for the magnesia industry， filling the data gap in emission factors for typical technological routes. It also proposes an emission factor estimation method applicable under conditions where online CO monitoring data are unavailable， which can provide methodological support for pollutant emission accounting and emission inventory development in similar data-constrained industries.
Magnesia production processes generate carbon monoxide （CO） emissions； however， publicly available measured data on CO emission factors for these processes remain scarce， which constrains the accuracy of emission accounting and mitigation assessment in the industry. To address the lack of basic data on CO emissions from typical magnesia production processes， this study selected three representative magnesia-producing enterprises in Anshan， Liaoning Province， China， covering three typical technological routes： the two-stage calcination process （“light burning-briquetting-shaft kiln dead burning”）， the “suspension calcination-dead burning sintering” process， and the electric arc furnace melting process. Under the condition that enterprises were not equipped with online CO monitoring modules， an estimation approach coupling manual measurements with conventional indicators from the Continuous Emission Monitoring System （CEMS） was developed. By establishing characteristic concentration ratios between CO and nitrogen oxides （NO x ） or particulate matter （PM）， and combining them with annual CEMS monitoring data， product-level CO emission factors were calculated. The results showed that the CO emission factors for the two-stage calcination process， the suspension calcination–dead burning sintering process， and the electric arc furnace melting process were 5.35， 5.18， and 1.40 kg/t， respectively， among which the emission level of the electric arc furnace melting process was significantly lower than that of sintering-based processes. This study provides enterprise-level measured CO parameters for the magnesia industry， filling the data gap in emission factors for typical technological routes. It also proposes an emission factor estimation method applicable under conditions where online CO monitoring data are unavailable， which can provide methodological support for pollutant emission accounting and emission inventory development in similar data-constrained industries.
2026, 44(4): 278-286.
doi: 10.13205/j.hjgc.202604028
Abstract:
This paper comprehensively and accurately calculated carbon budgets at the county level and explored their spatio-temporal evolution patterns， aiming to identify pathways for low-carbon economic development suited to each county and to contribute to achieving the carbon peaking and carbon neutrality goals of the Xinjiang Production and Construction Corps. From the perspectives of the entire terrestrial ecosystem and human activities encompassing energy consumption and human respiration， this study constructed a relatively comprehensive， accurate， and unified spatial model for measuring and evaluating carbon emissions， carbon absorption， and carbon budgets across spatial and temporal dimensions. This model was used to measure carbon absorption by the terrestrial ecosystem， human-induced carbon emissions， and carbon budgets in the Xinjiang Production and Construction Corps and its constituent divisions from 2010 to 2020， exploring their spatio-temporal evolution patterns at different scales， specifically the city and county levels. In addition， based on the economy contributive coefficient （ECC） and ecological support coefficient （ESC）， this paper conducted carbon balance zoning for each division. The results showed that： 1） The total carbon absorption of the terrestrial ecosystem consistently represented net carbon absorption， showing a continuous and slow decreasing trend， with carbon sequestration capacity in persistent decline. The only carbon source， cultivated land， expanded rapidly year by year in the direction of carbon sinks such as forests and grasslands. Human-induced carbon emissions exhibited a continuous and steady upward trend， although their growth rate began to decline sharply after 2015. Spatially， they presented a distribution pattern of "high in the north and east， low in the south and west". 2） Carbon emissions/absorptions underwent a process of rapid increase from 2010 to 2015， followed by slower growth from 2015 to 2020. Energy consumption was the most significant source of carbon emissions. The carbon emissions generated on construction land within each division accounted for 95% of the total carbon emissions/absorptions， reaching 99% for the entire study area. In terms of spatial distribution， except for the 14th Agricultural Division （characterized by vast land and sparse population and functioning as a net carbon absorber）， the other 12 divisions were all net carbon emitters， showing an obvious spatial differentiation pattern of "high in the north and east， low in the south and west". The high-value areas exhibited spatial consistency with the distribution of human-induced carbon emissions， expanding eastward from the 8th Agricultural Division in the Junggar Basin of northern Xinjiang. By 2020， the 8th， 13th， and 6th Agricultural Divisions （accounting for 26.52% of the land area） had emerged as high-density carbon emission zones， collectively bearing 78.16% of the net carbon emissions. 3） During the study period， both the high-carbon optimization zones and the low-carbon maintenance zones showed an expansion trend. In 2020， the divisions comprised one carbon sink functional zone， nine low-carbon maintenance zones， and three high-carbon optimization zones. The high-carbon optimization zones were distributed in a strip-shaped pattern， concentrated in the central and eastern areas， accounting for approximately 26.52% of the total area.
This paper comprehensively and accurately calculated carbon budgets at the county level and explored their spatio-temporal evolution patterns， aiming to identify pathways for low-carbon economic development suited to each county and to contribute to achieving the carbon peaking and carbon neutrality goals of the Xinjiang Production and Construction Corps. From the perspectives of the entire terrestrial ecosystem and human activities encompassing energy consumption and human respiration， this study constructed a relatively comprehensive， accurate， and unified spatial model for measuring and evaluating carbon emissions， carbon absorption， and carbon budgets across spatial and temporal dimensions. This model was used to measure carbon absorption by the terrestrial ecosystem， human-induced carbon emissions， and carbon budgets in the Xinjiang Production and Construction Corps and its constituent divisions from 2010 to 2020， exploring their spatio-temporal evolution patterns at different scales， specifically the city and county levels. In addition， based on the economy contributive coefficient （ECC） and ecological support coefficient （ESC）， this paper conducted carbon balance zoning for each division. The results showed that： 1） The total carbon absorption of the terrestrial ecosystem consistently represented net carbon absorption， showing a continuous and slow decreasing trend， with carbon sequestration capacity in persistent decline. The only carbon source， cultivated land， expanded rapidly year by year in the direction of carbon sinks such as forests and grasslands. Human-induced carbon emissions exhibited a continuous and steady upward trend， although their growth rate began to decline sharply after 2015. Spatially， they presented a distribution pattern of "high in the north and east， low in the south and west". 2） Carbon emissions/absorptions underwent a process of rapid increase from 2010 to 2015， followed by slower growth from 2015 to 2020. Energy consumption was the most significant source of carbon emissions. The carbon emissions generated on construction land within each division accounted for 95% of the total carbon emissions/absorptions， reaching 99% for the entire study area. In terms of spatial distribution， except for the 14th Agricultural Division （characterized by vast land and sparse population and functioning as a net carbon absorber）， the other 12 divisions were all net carbon emitters， showing an obvious spatial differentiation pattern of "high in the north and east， low in the south and west". The high-value areas exhibited spatial consistency with the distribution of human-induced carbon emissions， expanding eastward from the 8th Agricultural Division in the Junggar Basin of northern Xinjiang. By 2020， the 8th， 13th， and 6th Agricultural Divisions （accounting for 26.52% of the land area） had emerged as high-density carbon emission zones， collectively bearing 78.16% of the net carbon emissions. 3） During the study period， both the high-carbon optimization zones and the low-carbon maintenance zones showed an expansion trend. In 2020， the divisions comprised one carbon sink functional zone， nine low-carbon maintenance zones， and three high-carbon optimization zones. The high-carbon optimization zones were distributed in a strip-shaped pattern， concentrated in the central and eastern areas， accounting for approximately 26.52% of the total area.
