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2025, Volume 43, Issue 9
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2025,
43(9):
1-8.
doi: 10.13205/j.hjgc.202509001
Abstract:
In the context of enhanced requirements for wastewater treatment efficiency and increasingly stringent effluent standards for total nitrogen （TN）， this study conducted a systematic process optimization investigation at a wastewater treatment plant in Shenzhen with a designed capacity of 350000 m3/d. The plant combined a two-stage anoxic/oxic （AO） enhanced system for nitrogen removal on the basis of the anaeroxic/anoxic/oxic （A2O） process （i.e.， an A2O + multi-stage AO improved process）， but there were problems such as low utilization of carbon sources， insufficient use of the multi-stage AO， poor control of dissolved oxygen （DO） and fluctuations of TN in the effluent. In terms of process operating parameters， the influent distribution ratio among the anaerobic， anoxic zone 2， and anoxic zone 3 was adjusted from 7∶3∶0 to 4∶4∶2， while the internal recirculation was deactivated； regarding aeration control， the air-to-water ratio was reduced from 3∶1 to 2∶1； and in terms of pharmaceutical dosing， the number of carbon source dosing points was decreased from three （anaerobic zone， anoxic zone 2， and anoxic zone 3） to one （anoxic zone 3）. Under the premise of requiring no new structures， additional equipment， or production shutdown， dual objectives of reducing operating costs and improving effluent water quality were achieved. Following process optimization， the limitation on TN removal efficiency caused by internal reflux was eliminated， with the average TN concentration in the effluent decreasing from （11.93±1.37） mg/L to （8.11±2.00） mg/L. The raw water carbon source was efficiently allocated to each anoxic zone. As a result， the unit consumption of carbon source dosing decreased from 1.48 mg COD/L to 0.62 mg COD/L， with a reduction rate of 58.07%， while the unit electricity consumption dropped from 0.339 kW·h/m3 to 0.296 kW·h/m3， with a decrease rate of 12.88%. Over an 11-month operational period， carbon source dosing was reduced by 371.45 tons， electricity consumption decreased by 4221043.40 kW·h， and carbon emissions were cut by 3343488.47 kg CO2-eq. This process optimization not only enhanced the operational efficiency of the wastewater treatment plant but also achieved energy savings and emission reduction， providing valuable insights and reference for the optimization and upgrading of similar wastewater treatment plants.
In the context of enhanced requirements for wastewater treatment efficiency and increasingly stringent effluent standards for total nitrogen （TN）， this study conducted a systematic process optimization investigation at a wastewater treatment plant in Shenzhen with a designed capacity of 350000 m3/d. The plant combined a two-stage anoxic/oxic （AO） enhanced system for nitrogen removal on the basis of the anaeroxic/anoxic/oxic （A2O） process （i.e.， an A2O + multi-stage AO improved process）， but there were problems such as low utilization of carbon sources， insufficient use of the multi-stage AO， poor control of dissolved oxygen （DO） and fluctuations of TN in the effluent. In terms of process operating parameters， the influent distribution ratio among the anaerobic， anoxic zone 2， and anoxic zone 3 was adjusted from 7∶3∶0 to 4∶4∶2， while the internal recirculation was deactivated； regarding aeration control， the air-to-water ratio was reduced from 3∶1 to 2∶1； and in terms of pharmaceutical dosing， the number of carbon source dosing points was decreased from three （anaerobic zone， anoxic zone 2， and anoxic zone 3） to one （anoxic zone 3）. Under the premise of requiring no new structures， additional equipment， or production shutdown， dual objectives of reducing operating costs and improving effluent water quality were achieved. Following process optimization， the limitation on TN removal efficiency caused by internal reflux was eliminated， with the average TN concentration in the effluent decreasing from （11.93±1.37） mg/L to （8.11±2.00） mg/L. The raw water carbon source was efficiently allocated to each anoxic zone. As a result， the unit consumption of carbon source dosing decreased from 1.48 mg COD/L to 0.62 mg COD/L， with a reduction rate of 58.07%， while the unit electricity consumption dropped from 0.339 kW·h/m3 to 0.296 kW·h/m3， with a decrease rate of 12.88%. Over an 11-month operational period， carbon source dosing was reduced by 371.45 tons， electricity consumption decreased by 4221043.40 kW·h， and carbon emissions were cut by 3343488.47 kg CO2-eq. This process optimization not only enhanced the operational efficiency of the wastewater treatment plant but also achieved energy savings and emission reduction， providing valuable insights and reference for the optimization and upgrading of similar wastewater treatment plants.
2025,
43(9):
9-19.
doi: 10.13205/j.hjgc.202509002
Abstract:
Drinking water safety is fundamental to safeguarding human health and social development. With continuously improving national water quality standards， ceramic membranes—characterized by high separation efficiency and long service life—have demonstrated significant potential in the field of water treatment. Nano-functionalized ceramic membrane technology represents a cutting-edge approach to enhancing the quality and separation performance efficiency of drinking water. This paper provides a systematic review of recent advances in nanomaterial-modified ceramic membranes for drinking water treatment. First， an overview of the materials， structure， and separation mechanisms of ceramic membranes is provided. Subsequently， various modification strategies using nanomaterials are elaborated， with an analysis of their performance in drinking water treatment processes， including significantly improved membrane flux， enhanced contaminant removal， and fouling resistance. Finally， the challenges hindering the large-scale application of this technology are discussed， such as poor nanomaterial dispersion， potential nanomaterial leaching， membrane fouling issues， and then perspectives on future development pathways are proposed. This paper not only systematically reviews various modification systems and their performance but also focuses specifically on the technical bottlenecks encountered during the transition from laboratory research to large-scale implementation. It can offer insights for promoting in-depth research and future industrial applications of nano-functionalized ceramic membrane technology.
Drinking water safety is fundamental to safeguarding human health and social development. With continuously improving national water quality standards， ceramic membranes—characterized by high separation efficiency and long service life—have demonstrated significant potential in the field of water treatment. Nano-functionalized ceramic membrane technology represents a cutting-edge approach to enhancing the quality and separation performance efficiency of drinking water. This paper provides a systematic review of recent advances in nanomaterial-modified ceramic membranes for drinking water treatment. First， an overview of the materials， structure， and separation mechanisms of ceramic membranes is provided. Subsequently， various modification strategies using nanomaterials are elaborated， with an analysis of their performance in drinking water treatment processes， including significantly improved membrane flux， enhanced contaminant removal， and fouling resistance. Finally， the challenges hindering the large-scale application of this technology are discussed， such as poor nanomaterial dispersion， potential nanomaterial leaching， membrane fouling issues， and then perspectives on future development pathways are proposed. This paper not only systematically reviews various modification systems and their performance but also focuses specifically on the technical bottlenecks encountered during the transition from laboratory research to large-scale implementation. It can offer insights for promoting in-depth research and future industrial applications of nano-functionalized ceramic membrane technology.
2025,
43(9):
20-28.
doi: 10.13205/j.hjgc.202509003
Abstract:
Due to the insufficiency of available carbon sources and dissolved oxygen （DO） in the effluent， as well as the low temperature， the total nitrogen （TN） removal efficiency of traditional constructed wetlands is relatively low， accompanied by the release of considerable amounts of greenhouse gases （N2O， CO2， and CH4）. It has been shown that the TN removal rate of traditional CW is less than 50%， and with the continuous operation of the CW system， clogging problems will occur. In addition， the low temperature inhibits the activity of microorganisms， which in turn affects the normal play of their purification efficiency， resulting in a nitrogen removal efficiency of 30% below. In this study， biochar and pyrite were used as the substrates to investigate the nitrogen removal performance and greenhouse gas emissions of ordinary gravel and iron-carbon based constructed wetlands under tidal flow operation for the treatment of low carbon-to-nitrogen ratio （C/N） effluent from municipal wastewater treatment plants. The influence of temperature on the nitrogen removal performance of iron-carbon based constructed wetlands was further explored. The results showed that TN removal rates of iron-carbon based constructed wetlands at 10 ℃ and 25 ℃ were 13.07% and 17.32% higher than those of the ordinary gravel constructed wetlands， respectively. Prolonging the hydraulic retention time （HRT） could further enhance the nitrogen removal efficiency， and the greenhouse effect produced was not significantly higher than that of ordinary gravel constructed wetlands. Temperature changes did not affect the removal of ammonia nitrogen （NH4+-N） in municipal effluent by tidal flow constructed wetlands， but low temperature was unfavorable for the removal of nitrate nitrogen （NO3--N）， resulting in a low TN removal efficiency. The abundance of nitrification functional gene amoA and denitrification functional gene nosZ， as well as the activities of ammonia monooxygenase （AMO） and nitrous oxide reductase （NOS） in the iron-carbon based constructed wetland system， were significantly affected by temperature and HRT， which were the key factors influencing the TN removal efficiency in the wetland system.
Due to the insufficiency of available carbon sources and dissolved oxygen （DO） in the effluent， as well as the low temperature， the total nitrogen （TN） removal efficiency of traditional constructed wetlands is relatively low， accompanied by the release of considerable amounts of greenhouse gases （N2O， CO2， and CH4）. It has been shown that the TN removal rate of traditional CW is less than 50%， and with the continuous operation of the CW system， clogging problems will occur. In addition， the low temperature inhibits the activity of microorganisms， which in turn affects the normal play of their purification efficiency， resulting in a nitrogen removal efficiency of 30% below. In this study， biochar and pyrite were used as the substrates to investigate the nitrogen removal performance and greenhouse gas emissions of ordinary gravel and iron-carbon based constructed wetlands under tidal flow operation for the treatment of low carbon-to-nitrogen ratio （C/N） effluent from municipal wastewater treatment plants. The influence of temperature on the nitrogen removal performance of iron-carbon based constructed wetlands was further explored. The results showed that TN removal rates of iron-carbon based constructed wetlands at 10 ℃ and 25 ℃ were 13.07% and 17.32% higher than those of the ordinary gravel constructed wetlands， respectively. Prolonging the hydraulic retention time （HRT） could further enhance the nitrogen removal efficiency， and the greenhouse effect produced was not significantly higher than that of ordinary gravel constructed wetlands. Temperature changes did not affect the removal of ammonia nitrogen （NH4+-N） in municipal effluent by tidal flow constructed wetlands， but low temperature was unfavorable for the removal of nitrate nitrogen （NO3--N）， resulting in a low TN removal efficiency. The abundance of nitrification functional gene amoA and denitrification functional gene nosZ， as well as the activities of ammonia monooxygenase （AMO） and nitrous oxide reductase （NOS） in the iron-carbon based constructed wetland system， were significantly affected by temperature and HRT， which were the key factors influencing the TN removal efficiency in the wetland system.
2025,
43(9):
29-38.
doi: 10.13205/j.hjgc.202509004
Abstract:
In the current landscape of industrial wastewater treatment， high energy and material consumption is widespread and poses significant challenges. Consequently， implementing strategies focused on energy conservation， efficiency improvement， and resource recovery has become essential to address these issues. This comprehensive study， focusing on coking wastewater treatment， seeks to develop an advanced synergistic strategy between resource recovery and stringent pollution control， by utilizing an innovative platform that couples physicochemical pre- and post-treatment with the OHO biological process. The findings revealed that ferrous salts demonstrated outstanding performance in the effective removal of cyanide ions （CN-） and sulfide ions （S2-） during the preliminary physicochemical treatment stage. Furthermore， the synergistic application of poly-ferric sulfate （PFS） combined with activated carbon （AC） has been proven to enable highly efficient purification of effluent discharged from biological treatment processes. By utilizing an advanced correlation analysis coupled model， the operational parameters of the preliminary physicochemical treatment unit were systematically refined， leading to the adjustment and reduction of the FeSO4·7H2O dosage to an optimized level of 120 mg/L. Additionally， through the application of response surface analysis， the study successfully achieved significant reductions in the dosages of both activated carbon （AC） and poly-ferric sulfate （PFS）， decreasing them by 130 mg/L and 100 mg/L， respectively. Furthermore， the strategic introduction of a meticulously engineered sludge countercurrent recycling mechanism demonstrated—through detailed engineering applications and practical verification—that the optimized effluent concentrations of COD， TN， CN-， and S2- were remarkably reduced from their original levels of （3750±12），（300±28），（26.7±2.4），（143±15） mg/L to impressively low levels of （44.6±8.0），（15.7±2.5），（0.12±0.02），（0.08±0.01） mg/L， respectively. This achievement successfully accomplished the deep reduction of pollutant emissions， demonstrating the effectiveness of the method in significantly lowering contaminant levels. Meanwhile， in comparison with conventional operational paradigms， this novel approach has been proven to deliver a significant reduction in operational costs， amounting to 2.31 yuan/m3， highlighting its profound economic and ecological benefits. These results demonstrate that by assigning specific， clearly defined roles and tailored functional objectives to each unit within the system， and by systematically exploring the deeply interconnected mechanisms across diverse treatment stages， the goals of wastewater treatment system optimization can be comprehensively and effectively realized.
In the current landscape of industrial wastewater treatment， high energy and material consumption is widespread and poses significant challenges. Consequently， implementing strategies focused on energy conservation， efficiency improvement， and resource recovery has become essential to address these issues. This comprehensive study， focusing on coking wastewater treatment， seeks to develop an advanced synergistic strategy between resource recovery and stringent pollution control， by utilizing an innovative platform that couples physicochemical pre- and post-treatment with the OHO biological process. The findings revealed that ferrous salts demonstrated outstanding performance in the effective removal of cyanide ions （CN-） and sulfide ions （S2-） during the preliminary physicochemical treatment stage. Furthermore， the synergistic application of poly-ferric sulfate （PFS） combined with activated carbon （AC） has been proven to enable highly efficient purification of effluent discharged from biological treatment processes. By utilizing an advanced correlation analysis coupled model， the operational parameters of the preliminary physicochemical treatment unit were systematically refined， leading to the adjustment and reduction of the FeSO4·7H2O dosage to an optimized level of 120 mg/L. Additionally， through the application of response surface analysis， the study successfully achieved significant reductions in the dosages of both activated carbon （AC） and poly-ferric sulfate （PFS）， decreasing them by 130 mg/L and 100 mg/L， respectively. Furthermore， the strategic introduction of a meticulously engineered sludge countercurrent recycling mechanism demonstrated—through detailed engineering applications and practical verification—that the optimized effluent concentrations of COD， TN， CN-， and S2- were remarkably reduced from their original levels of （3750±12），（300±28），（26.7±2.4），（143±15） mg/L to impressively low levels of （44.6±8.0），（15.7±2.5），（0.12±0.02），（0.08±0.01） mg/L， respectively. This achievement successfully accomplished the deep reduction of pollutant emissions， demonstrating the effectiveness of the method in significantly lowering contaminant levels. Meanwhile， in comparison with conventional operational paradigms， this novel approach has been proven to deliver a significant reduction in operational costs， amounting to 2.31 yuan/m3， highlighting its profound economic and ecological benefits. These results demonstrate that by assigning specific， clearly defined roles and tailored functional objectives to each unit within the system， and by systematically exploring the deeply interconnected mechanisms across diverse treatment stages， the goals of wastewater treatment system optimization can be comprehensively and effectively realized.
2025,
43(9):
39-47.
doi: 10.13205/j.hjgc.202509005
Abstract:
The oxygen transfer efficiency （OTE） of aerators is crucial for the on-site operation of these wastewater treatment plants， and accurately determining the OTE can guide these plants to save energy and reduce consumption. In order to meet the demand for assessing the mass transfer performance of aerators under actual process conditions， this study employed the off-gas analysis method to determine the oxygen transfer efficiency under process conditions （αSOTE） and conducted an impact optimization study. In this study， the effects of the molar fractions of oxygen， carbon dioxide， and water vapor on the testing accuracy of dynamic and static complete off-gas analysis methods were firstly compared. Subsequently， municipal wastewater treatment plants with different treatment processes （A2/O， step aeration process， SBR） were selected. The off-gas analysis method with less influence on testing accuracy was used for on-site testing to investigate the change rules of the OTE of the aerator under different operating conditions， such as treatment processes， sludge concentrations， and sludge ages， etc. The results showed that the static complete off-gas analysis method had no significant influence on the OTE. Moreover， the testing accuracy of this method was less affected； when the OTE value exceeded 16%， the calculation error was only 1%. A field study based on the static complete off-gas analysis method revealed that αSOTE decreased with the increase of sludge concentration and sludge age. αSOTE was significantly affected by influent water quality. In plug-flow aeration basins， αSOTE increased with increasing distance from the inlet.
The oxygen transfer efficiency （OTE） of aerators is crucial for the on-site operation of these wastewater treatment plants， and accurately determining the OTE can guide these plants to save energy and reduce consumption. In order to meet the demand for assessing the mass transfer performance of aerators under actual process conditions， this study employed the off-gas analysis method to determine the oxygen transfer efficiency under process conditions （αSOTE） and conducted an impact optimization study. In this study， the effects of the molar fractions of oxygen， carbon dioxide， and water vapor on the testing accuracy of dynamic and static complete off-gas analysis methods were firstly compared. Subsequently， municipal wastewater treatment plants with different treatment processes （A2/O， step aeration process， SBR） were selected. The off-gas analysis method with less influence on testing accuracy was used for on-site testing to investigate the change rules of the OTE of the aerator under different operating conditions， such as treatment processes， sludge concentrations， and sludge ages， etc. The results showed that the static complete off-gas analysis method had no significant influence on the OTE. Moreover， the testing accuracy of this method was less affected； when the OTE value exceeded 16%， the calculation error was only 1%. A field study based on the static complete off-gas analysis method revealed that αSOTE decreased with the increase of sludge concentration and sludge age. αSOTE was significantly affected by influent water quality. In plug-flow aeration basins， αSOTE increased with increasing distance from the inlet.
2025,
43(9):
48-55.
doi: 10.13205/j.hjgc.202509006
Abstract:
The wastewater from the production of Sauce-flavored Baijiu is characterized by high concentrations of slag sand， suspended solids， and organic matter， and the pretreatment process is a key step in wastewater treatment. If the by-products such as dregs and husks generated during the Baijiu brewing process are not removed efficiently， they will impose an extremely high operational load on the subsequent wastewater treatment processes. Additionally， the presence of these by-products can cause severe damage to the equipment. The abrasion and clogging caused by slag sand and other substances may reduce the service life and efficiency of the equipment， resulting in frequent maintenance， higher replacement costs， and even unstable effluent quality. This study conducted a pretreatment enhancement test at the Zhonghua Wastewater Treatment Plant under Kweichow Moutai Co.， Ltd. Using an innovative mesh-belt solid-liquid rapid separation device， the study investigated the efficiency of slag sand removal， treatment capacity， and energy and material consumption at different treatment precision levels. It also assessed the feasibility of wastewater resource utilization. The results clearly showed that the mesh-belt solid-liquid rapid separation equipment offered significant advantages over the current pretreatment process. The comprehensive removal efficiency of slag and sand larger than 200 μm consistently reached over 90%. It not only ensured high removal efficiency for larger slag sand particles but also significantly contributed to the overall wastewater treatment process. Moreover， it saved 62% in land area， a significant advantage in terms of space utilization. In terms of energy consumption， it reduced electricity consumption for operating by 80%. In terms of environmental friendliness， it decreased theoretical odor generation by 90%. These findings provide valuable insights for improving the wastewater treatment efficiency of Sauce-flavored Baijiu production. Additionally， by using extremely high-precision filter meshes， the mesh-belt solid-liquid rapid separation device can effectively recover protein and fat from the dregs. This recovery process provides a valuable source of resources that can potentially be reused. It offers a feasible technical solution for the green and low-carbon operation of Sauce-flavored Baijiu production wastewater treatment plants.
The wastewater from the production of Sauce-flavored Baijiu is characterized by high concentrations of slag sand， suspended solids， and organic matter， and the pretreatment process is a key step in wastewater treatment. If the by-products such as dregs and husks generated during the Baijiu brewing process are not removed efficiently， they will impose an extremely high operational load on the subsequent wastewater treatment processes. Additionally， the presence of these by-products can cause severe damage to the equipment. The abrasion and clogging caused by slag sand and other substances may reduce the service life and efficiency of the equipment， resulting in frequent maintenance， higher replacement costs， and even unstable effluent quality. This study conducted a pretreatment enhancement test at the Zhonghua Wastewater Treatment Plant under Kweichow Moutai Co.， Ltd. Using an innovative mesh-belt solid-liquid rapid separation device， the study investigated the efficiency of slag sand removal， treatment capacity， and energy and material consumption at different treatment precision levels. It also assessed the feasibility of wastewater resource utilization. The results clearly showed that the mesh-belt solid-liquid rapid separation equipment offered significant advantages over the current pretreatment process. The comprehensive removal efficiency of slag and sand larger than 200 μm consistently reached over 90%. It not only ensured high removal efficiency for larger slag sand particles but also significantly contributed to the overall wastewater treatment process. Moreover， it saved 62% in land area， a significant advantage in terms of space utilization. In terms of energy consumption， it reduced electricity consumption for operating by 80%. In terms of environmental friendliness， it decreased theoretical odor generation by 90%. These findings provide valuable insights for improving the wastewater treatment efficiency of Sauce-flavored Baijiu production. Additionally， by using extremely high-precision filter meshes， the mesh-belt solid-liquid rapid separation device can effectively recover protein and fat from the dregs. This recovery process provides a valuable source of resources that can potentially be reused. It offers a feasible technical solution for the green and low-carbon operation of Sauce-flavored Baijiu production wastewater treatment plants.
2025,
43(9):
56-65.
doi: 10.13205/j.hjgc.202509007
Abstract:
Two parallel reactors were established in this study： a conventional aeration （R1） and a ceramic membrane micro-nano aeration （R2）. The oxygen transfer performance， nitrite accumulation effect， oxidative stress levels， microbial community structure， and metabolic processes of the two reactors were probed and compared， and the mechanism of nitrite accumulation， which is promoted by ceramic membrane micro-nano aeration in the partial nitrification （PN） process， was thoroughly analyzed. The results of clean water aeration test showed that ceramic membrane micro-nano aeration exhibited strong oxygen transfer capacity， with a standard oxygen transfer efficiency （SOTE） of 51.92%， three times higher than that of conventional aeration （17.43%）. After 121 days of operation， R2 demonstrated an earlier occurrence of nitrite accumulation， with a nitrite accumulation rate （NAR） of 91.86%， significantly higher than that of R1 （83.05%）. The oxidative stress tests further verified that nitrite-oxidizing bacteria （NOB） were more sensitive to oxidative stress induced by ceramic membrane micro-nano aeration. This ultimately provided ammonia-oxidizing bacteria （AOB） with a relative growth advantage. EPR detection confirmed that ceramic membrane micro-nano aeration generated ·OH radicals in water， which triggered oxidative stress in nitrifying bacteria and reduced their activity. High-throughput sequencing revealed that the abundances of AOB （Nitrosomonas） in R1 and R2 were similar， while the relative abundance of NOB （Nitrospira） in R2 （1.66%） was significantly lower than in R1 （3.54%）. This proved that the different inhibitory effects of ceramic membrane micro-nano aeration enhanced the growth of AOB. Metagenomic analysis indicated that the metabolic level related to the ammonia oxidation process was less affected under ceramic membrane micro-nano aeration. Moreover， the nitrifying bacteria （primarily AOB） exhibited enhanced antioxidant defenses， mitigating the adverse effects of oxidative stress. Therefore， compared to conventional aeration， ceramic membrane micro-nano aeration achieved superior nitrite accumulation in PN process. This research provided theoretical support for advancement of PN technology and the practical application of mainstream Anammox.
Two parallel reactors were established in this study： a conventional aeration （R1） and a ceramic membrane micro-nano aeration （R2）. The oxygen transfer performance， nitrite accumulation effect， oxidative stress levels， microbial community structure， and metabolic processes of the two reactors were probed and compared， and the mechanism of nitrite accumulation， which is promoted by ceramic membrane micro-nano aeration in the partial nitrification （PN） process， was thoroughly analyzed. The results of clean water aeration test showed that ceramic membrane micro-nano aeration exhibited strong oxygen transfer capacity， with a standard oxygen transfer efficiency （SOTE） of 51.92%， three times higher than that of conventional aeration （17.43%）. After 121 days of operation， R2 demonstrated an earlier occurrence of nitrite accumulation， with a nitrite accumulation rate （NAR） of 91.86%， significantly higher than that of R1 （83.05%）. The oxidative stress tests further verified that nitrite-oxidizing bacteria （NOB） were more sensitive to oxidative stress induced by ceramic membrane micro-nano aeration. This ultimately provided ammonia-oxidizing bacteria （AOB） with a relative growth advantage. EPR detection confirmed that ceramic membrane micro-nano aeration generated ·OH radicals in water， which triggered oxidative stress in nitrifying bacteria and reduced their activity. High-throughput sequencing revealed that the abundances of AOB （Nitrosomonas） in R1 and R2 were similar， while the relative abundance of NOB （Nitrospira） in R2 （1.66%） was significantly lower than in R1 （3.54%）. This proved that the different inhibitory effects of ceramic membrane micro-nano aeration enhanced the growth of AOB. Metagenomic analysis indicated that the metabolic level related to the ammonia oxidation process was less affected under ceramic membrane micro-nano aeration. Moreover， the nitrifying bacteria （primarily AOB） exhibited enhanced antioxidant defenses， mitigating the adverse effects of oxidative stress. Therefore， compared to conventional aeration， ceramic membrane micro-nano aeration achieved superior nitrite accumulation in PN process. This research provided theoretical support for advancement of PN technology and the practical application of mainstream Anammox.
2025,
43(9):
66-71.
doi: 10.13205/j.hjgc.202509008
Abstract:
With the gradual improvement of the total phosphorus standard for effluent， chemical phosphorus removal has become an indispensable process unit in wastewater treatment plants. To ensure the stable and compliant discharge of total phosphorus， the excessive addition of phosphorus removal chemicals is a common issue. However， few intelligent dosing schemes have demonstrated significant operational effects in practice. This paper took the deep phosphorus removal in the air flotation process section of an actual wastewater treatment plant as an example. It comprehensively considered the characteristics of large fluctuations in water quality and quantity during actual operation， established an intelligent dosing algorithm with phosphorus loading （kg/h） as the core control strategy， and conducted actual testing and analysis of PAC dosage under different phosphate concentrations. Moreover， a model for matching the key parameters of the dynamic Al/P molar ratio was established to calculate the PAC dosage in real time and control the flow output of the dosing pump. The results showed that the average chemical consumption of the intelligent phosphorus removal system decreased from 0.71 t per 104 t of water to 0.45 t per 104 t of water after operation， representing a significant reduction of 36.6%. The implementation of the system not only reduced the operating costs of the wastewater treatment plant but also decreased the residual metal ions in the receiving water body， generating significant economic and environmental benefits. It is of great significance for exploring low-carbon operation and refined control of wastewater treatment plants.
With the gradual improvement of the total phosphorus standard for effluent， chemical phosphorus removal has become an indispensable process unit in wastewater treatment plants. To ensure the stable and compliant discharge of total phosphorus， the excessive addition of phosphorus removal chemicals is a common issue. However， few intelligent dosing schemes have demonstrated significant operational effects in practice. This paper took the deep phosphorus removal in the air flotation process section of an actual wastewater treatment plant as an example. It comprehensively considered the characteristics of large fluctuations in water quality and quantity during actual operation， established an intelligent dosing algorithm with phosphorus loading （kg/h） as the core control strategy， and conducted actual testing and analysis of PAC dosage under different phosphate concentrations. Moreover， a model for matching the key parameters of the dynamic Al/P molar ratio was established to calculate the PAC dosage in real time and control the flow output of the dosing pump. The results showed that the average chemical consumption of the intelligent phosphorus removal system decreased from 0.71 t per 104 t of water to 0.45 t per 104 t of water after operation， representing a significant reduction of 36.6%. The implementation of the system not only reduced the operating costs of the wastewater treatment plant but also decreased the residual metal ions in the receiving water body， generating significant economic and environmental benefits. It is of great significance for exploring low-carbon operation and refined control of wastewater treatment plants.
2025,
43(9):
72-81.
doi: 10.13205/j.hjgc.202509009
Abstract:
Formation process is a key step for a moving bed biofilm reactor （MBBR）， and the hydraulic retention time （HRT） is one of the key influencing factors. This study established four biofilm reactors， using raw water from a sewage treatment plant as the influent to explore the effects of different HRT strategies on biomass and microbial community structure of biofilm. Results revealed that the short HRT strategy （2 h） achieved a biomass of （21.23±1.2） mg SS/carrier in 15 d， which showed significant advantages compared with the three strategies： no water intake， long HRT strategy （6 h） and long-short HRT switching strategy （6 h → 2 h）. SEM and MiSeq Illumina analysis of the samples at 15 d， 32 d， and 57 d revealed that the microbial community structure of the biofilm changed significantly over time. Acinetobacter and Pseudomonas were the main genera with an increasing trend， while Ottowia and Acidovorax were the main genera with a decreasing trend. However， the H-test for α-diversity and the ANOSIM/Adonis test for β-diversity of the microbial community structure revealed no significant differences among the four groups under different HRT strategies. This indicates that different HRT strategies influence the biomass of the biofilm but have no significant effect on its microbial community structure. Based on these findings， this study proposes a functional biofilm initiation method described as "biofilm attachment first， domestication afterward".
Formation process is a key step for a moving bed biofilm reactor （MBBR）， and the hydraulic retention time （HRT） is one of the key influencing factors. This study established four biofilm reactors， using raw water from a sewage treatment plant as the influent to explore the effects of different HRT strategies on biomass and microbial community structure of biofilm. Results revealed that the short HRT strategy （2 h） achieved a biomass of （21.23±1.2） mg SS/carrier in 15 d， which showed significant advantages compared with the three strategies： no water intake， long HRT strategy （6 h） and long-short HRT switching strategy （6 h → 2 h）. SEM and MiSeq Illumina analysis of the samples at 15 d， 32 d， and 57 d revealed that the microbial community structure of the biofilm changed significantly over time. Acinetobacter and Pseudomonas were the main genera with an increasing trend， while Ottowia and Acidovorax were the main genera with a decreasing trend. However， the H-test for α-diversity and the ANOSIM/Adonis test for β-diversity of the microbial community structure revealed no significant differences among the four groups under different HRT strategies. This indicates that different HRT strategies influence the biomass of the biofilm but have no significant effect on its microbial community structure. Based on these findings， this study proposes a functional biofilm initiation method described as "biofilm attachment first， domestication afterward".
2025,
43(9):
82-91.
doi: 10.13205/j.hjgc.202509010
Abstract:
Microorganisms， especially bacteria， play a crucial role in wastewater treatment processes. However， effluent from wastewater treatment plants releases bacteria， especially pathogenic bacteria， into the water environment. The health risks are a hidden danger that cannot be ignored. This study focuses on four different types of wastewater treatment systems， collected samples from influent， effluent from secondary sedimentation tanks （after biological treatment）， final effluent （after chemical treatment）， and conducted analysis of the physicochemical properties and bacterial community structures， as well as the influencing factors of the water samples. Community structure analysis showed that the Alpha and Beta diversity of non-pathogenic bacterial communities did not undergo significant changes during the wastewater treatment process， with 96% of total species present at all sites. The Shannon index of the pathogenic community in the effluent significantly reduced compared to the influent. In different wastewater treatment systems， the dynamics of pathogenic bacterial communities vary， and the relative abundance of some pathogenic bacteria increases in the effluent. The co-occurrence network shows that species with higher abundance in non-pathogenic communities have a stronger co-occurrence relationship with antibiotic resistance genes （ARGs）， while species with relatively lower abundance in pathogens have a relatively stronger co-occurrence relationship with ARGs. The influent community is more affected by pollution factors such as COD， total nitrogen， and total phosphorus， while the communities in the secondary sedimentation tanks and the effluents are affected by pH value. The pathogenic bacterial community is significantly affected by pH value. This study comprehensively reveals the distribution and characteristics of bacterial communities along the treatment processes of different wastewater treatment plants， indicating the potential health risks of pathogenic bacteria discharged to the receiving environment.
Microorganisms， especially bacteria， play a crucial role in wastewater treatment processes. However， effluent from wastewater treatment plants releases bacteria， especially pathogenic bacteria， into the water environment. The health risks are a hidden danger that cannot be ignored. This study focuses on four different types of wastewater treatment systems， collected samples from influent， effluent from secondary sedimentation tanks （after biological treatment）， final effluent （after chemical treatment）， and conducted analysis of the physicochemical properties and bacterial community structures， as well as the influencing factors of the water samples. Community structure analysis showed that the Alpha and Beta diversity of non-pathogenic bacterial communities did not undergo significant changes during the wastewater treatment process， with 96% of total species present at all sites. The Shannon index of the pathogenic community in the effluent significantly reduced compared to the influent. In different wastewater treatment systems， the dynamics of pathogenic bacterial communities vary， and the relative abundance of some pathogenic bacteria increases in the effluent. The co-occurrence network shows that species with higher abundance in non-pathogenic communities have a stronger co-occurrence relationship with antibiotic resistance genes （ARGs）， while species with relatively lower abundance in pathogens have a relatively stronger co-occurrence relationship with ARGs. The influent community is more affected by pollution factors such as COD， total nitrogen， and total phosphorus， while the communities in the secondary sedimentation tanks and the effluents are affected by pH value. The pathogenic bacterial community is significantly affected by pH value. This study comprehensively reveals the distribution and characteristics of bacterial communities along the treatment processes of different wastewater treatment plants， indicating the potential health risks of pathogenic bacteria discharged to the receiving environment.
2025,
43(9):
92-106.
doi: 10.13205/j.hjgc.202509011
Abstract:
Functional biofilms， which perform one or a combination of enhanced functions such as nitrification， denitrification， and anaerobic ammonium oxidation， are key components in technologies like the moving bed biofilm reactor （MBBR） and integrated fixed activated sludge （IFAS）. Biofilm attachment， domestication， and the enrichment of functional microbial communities are key steps for biofilm technologies. This study systematically summarized the factors influencing functional biofilm growth and the directional enrichment of specific microorganisms in terms of operational schemes， environmental conditions， hydraulic characteristics， microbial characteristics， and packing material properties. In addition， the key design parameters for biofilm reactors were reviewed， and recommendations were provided for the selection of parameters such as the C/N ratio， hydraulic retention time （HRT）， and packing ratio. Finally， a comprehensive strategy for the attachment and domestication of functional biofilms was proposed. Future research should focus on the hydraulics and microbiology in the process of attachment， deepen the understanding of microbial community succession patterns and the metabolic mechanisms of functional bacterial groups during domestication， and develop effective operational strategies for these processes.
Functional biofilms， which perform one or a combination of enhanced functions such as nitrification， denitrification， and anaerobic ammonium oxidation， are key components in technologies like the moving bed biofilm reactor （MBBR） and integrated fixed activated sludge （IFAS）. Biofilm attachment， domestication， and the enrichment of functional microbial communities are key steps for biofilm technologies. This study systematically summarized the factors influencing functional biofilm growth and the directional enrichment of specific microorganisms in terms of operational schemes， environmental conditions， hydraulic characteristics， microbial characteristics， and packing material properties. In addition， the key design parameters for biofilm reactors were reviewed， and recommendations were provided for the selection of parameters such as the C/N ratio， hydraulic retention time （HRT）， and packing ratio. Finally， a comprehensive strategy for the attachment and domestication of functional biofilms was proposed. Future research should focus on the hydraulics and microbiology in the process of attachment， deepen the understanding of microbial community succession patterns and the metabolic mechanisms of functional bacterial groups during domestication， and develop effective operational strategies for these processes.
2025,
43(9):
107-118.
doi: 10.13205/j.hjgc.202509012
Abstract:
The global spread of antibiotic resistance has emerged as a major public health concern. Wastewater treatment systems are regarded as key reservoirs and dissemination routes for antibiotic resistance genes （ARGs）， and increasing attention has been directed toward the microbial ecological processes within these systems. Bacteriophages， as bacterial viruses and potential mediators of gene transfer， play a dual role in this process. They can eliminate resistant bacteria through lysis while also facilitating the horizontal transfer of ARGs through transduction. This dual functionality presents both opportunities and challenges in the regulation of gene dissemination. In this study， bibliometric analysis was used to systematically examine global research literature from 1980 to 2024， with a focus on the mechanisms by which bacteriophages influence the spread of ARGs in wastewater treatment systems. The findings provide a theoretical foundation for the development of targeted strategies to control the spread of antibiotic resistance.
The global spread of antibiotic resistance has emerged as a major public health concern. Wastewater treatment systems are regarded as key reservoirs and dissemination routes for antibiotic resistance genes （ARGs）， and increasing attention has been directed toward the microbial ecological processes within these systems. Bacteriophages， as bacterial viruses and potential mediators of gene transfer， play a dual role in this process. They can eliminate resistant bacteria through lysis while also facilitating the horizontal transfer of ARGs through transduction. This dual functionality presents both opportunities and challenges in the regulation of gene dissemination. In this study， bibliometric analysis was used to systematically examine global research literature from 1980 to 2024， with a focus on the mechanisms by which bacteriophages influence the spread of ARGs in wastewater treatment systems. The findings provide a theoretical foundation for the development of targeted strategies to control the spread of antibiotic resistance.
2025,
43(9):
119-126.
doi: 10.13205/j.hjgc.202509013
Abstract:
The sludge densification technology based on hydrocyclone was expected to address the operational bottlenecks faced by sewage treatment plants due to the increase in treatment load. However， there was still a lack of research on operational optimization and control of hydrocyclone to achieve precise optimization on sludge settling performance. To improve the densification efficiency of this technology， this study systematically compared the differences in particle size distribution and sedimentation performance of wet sludge under low （1 m/s） and high （3 m/s） flow velocity condition. The results showed that， compared with the low flow velocity， the high flow velocity significantly enhanced the separation efficiency of the underflow and overflow sludge， making the proportion of large biological aggregates （≥150 μm） in the underflow 10.6% higher than that in the overflow sludge. After densification enhancement， the SVI30 of the underflow sludge decreased from 101.3 to 89.1 mL/g， and the sedimentation performance was significantly improved （P < 0.05）， while the SVI30 of the rejected overflow sludge was as high as 124.9 mL/g. In terms of functional performance， the nitrification， denitrification and phosphorus release rates of the densified sludge increased by 3.3%， 7.2% and 12.2%， respectively. The analysis of the dominant flora further revealed that the relative abundance of Delftia， which has both a high EPS secretion capacity and simultaneous nitrification and denitrification performance， increased by 3.02% in the densified group， ensuring the aggregation of sludge and improvement of nitrogen removal capacity. In addition， the abundances of Acinetobacter and Dechloromonas with potential for denitrifying phosphorus removal slightly decreased after densification， but they may still play a key role in improving the nitrogen and phosphorus removal function. This study clarified the significant impact of flow rate regulation of the hydrocyclone on sludge densification effect. In the future， it is necessary to combine molecular biological methods and kinetic modelling to promote the development of parameter optimization and intelligent control strategies for hydrocyclone.
The sludge densification technology based on hydrocyclone was expected to address the operational bottlenecks faced by sewage treatment plants due to the increase in treatment load. However， there was still a lack of research on operational optimization and control of hydrocyclone to achieve precise optimization on sludge settling performance. To improve the densification efficiency of this technology， this study systematically compared the differences in particle size distribution and sedimentation performance of wet sludge under low （1 m/s） and high （3 m/s） flow velocity condition. The results showed that， compared with the low flow velocity， the high flow velocity significantly enhanced the separation efficiency of the underflow and overflow sludge， making the proportion of large biological aggregates （≥150 μm） in the underflow 10.6% higher than that in the overflow sludge. After densification enhancement， the SVI30 of the underflow sludge decreased from 101.3 to 89.1 mL/g， and the sedimentation performance was significantly improved （P < 0.05）， while the SVI30 of the rejected overflow sludge was as high as 124.9 mL/g. In terms of functional performance， the nitrification， denitrification and phosphorus release rates of the densified sludge increased by 3.3%， 7.2% and 12.2%， respectively. The analysis of the dominant flora further revealed that the relative abundance of Delftia， which has both a high EPS secretion capacity and simultaneous nitrification and denitrification performance， increased by 3.02% in the densified group， ensuring the aggregation of sludge and improvement of nitrogen removal capacity. In addition， the abundances of Acinetobacter and Dechloromonas with potential for denitrifying phosphorus removal slightly decreased after densification， but they may still play a key role in improving the nitrogen and phosphorus removal function. This study clarified the significant impact of flow rate regulation of the hydrocyclone on sludge densification effect. In the future， it is necessary to combine molecular biological methods and kinetic modelling to promote the development of parameter optimization and intelligent control strategies for hydrocyclone.
2025,
43(9):
127-138.
doi: 10.13205/j.hjgc.202509014
Abstract:
Domestic wastewater， characterized by its substantial discharge volume and resource recovery potential， holds significant importance for energy recovery through the concentration of organic matter. Currently， coagulation-sedimentation stands as the predominant method for wastewater concentration. This study investigated coagulation process optimization using wastewater from the treatment plant of Xi'an Siyuan University， focusing on the impacts of coagulant type （FeCl3·6H2O vs. PAC）， dosage （30~500 mg/L）， sedimentation time （15~120 min）， and initial pH （3~8） on carbon source capture and phosphorus enrichment. A subsequent dynamic biochar adsorption column （45 cm height， 4 mL/min flow rate） was employed to further treat coagulated effluent， achieving compliance with Class 1A in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant ［ρ（COD） < 50 mg/L， ρ（NH4+-N） < 5 mg/L］. Ultrasonic-assisted desorption-regeneration cycles （0.5 mol/L HCl， 30°C， 75 min ultrasonication） enhanced desorption efficiency while enabling closed-loop resource recovery through the reuse of HCl for pH adjustment.Key findings include：Optimal coagulation at 300 mg/L FeCl3·6H2O， 30 min sedimentation， and pH value of 6， achieved 67.76% COD capture and >98% TP/PO43--P enrichment. Modified corncob biochar maintained >50% COD/NH4+-N adsorption capacity after 5 regeneration cycles. Ultrasonic desorption boosted COD/NH4+-N desorption rates to （94.65±0.01）% and （94.25±0.05）%， respectively， with process duration reduced by 83.3% to 92.2% versus the conventional methods.This integrated strategy provides a scientifically validated solution for simultaneous wastewater purification and resource recovery， aligning with circular economy principles in municipal wastewater treatment.
Domestic wastewater， characterized by its substantial discharge volume and resource recovery potential， holds significant importance for energy recovery through the concentration of organic matter. Currently， coagulation-sedimentation stands as the predominant method for wastewater concentration. This study investigated coagulation process optimization using wastewater from the treatment plant of Xi'an Siyuan University， focusing on the impacts of coagulant type （FeCl3·6H2O vs. PAC）， dosage （30~500 mg/L）， sedimentation time （15~120 min）， and initial pH （3~8） on carbon source capture and phosphorus enrichment. A subsequent dynamic biochar adsorption column （45 cm height， 4 mL/min flow rate） was employed to further treat coagulated effluent， achieving compliance with Class 1A in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant ［ρ（COD） < 50 mg/L， ρ（NH4+-N） < 5 mg/L］. Ultrasonic-assisted desorption-regeneration cycles （0.5 mol/L HCl， 30°C， 75 min ultrasonication） enhanced desorption efficiency while enabling closed-loop resource recovery through the reuse of HCl for pH adjustment.Key findings include：Optimal coagulation at 300 mg/L FeCl3·6H2O， 30 min sedimentation， and pH value of 6， achieved 67.76% COD capture and >98% TP/PO43--P enrichment. Modified corncob biochar maintained >50% COD/NH4+-N adsorption capacity after 5 regeneration cycles. Ultrasonic desorption boosted COD/NH4+-N desorption rates to （94.65±0.01）% and （94.25±0.05）%， respectively， with process duration reduced by 83.3% to 92.2% versus the conventional methods.This integrated strategy provides a scientifically validated solution for simultaneous wastewater purification and resource recovery， aligning with circular economy principles in municipal wastewater treatment.
2025,
43(9):
139-147.
doi: 10.13205/j.hjgc.202509015
Abstract:
Under the background of national carbon peak and carbon neutrality in China，achieving low-cost and high-efficiency flue gas carbon capture is of great significance. As the most mature flue gas capture scheme， MEA absorption technology has been widely used in various industries carbon capture processes. The catalytically-enhanced regeneration method plays an important role in reducing the energy consumption in processes. In this work， by combining the process simulation approach in Aspen Plus， the conventional and catalytically-enhanced regeneration of MEA flue gas decarbonization processes were simulated and analyzed， aiming to clarify the technical advantages of the catalytically-enhanced regeneration method. Firstly， Aspen Plus was employed to simulate the conventional MEA flue gas decarbonization process， examining the impact of key operational parameters such as absorption temperature， gas-liquid ratio， and desorption temperature on the absorption efficiency. This analysis provided insights into the optimal operation of the MEA absorption and desorption processes， as well as an energy-efficient operational scheme. Secondly， by incorporating a catalytic hypothesis， a MEA decarbonization process with catalytically-enhanced regeneration was developed and simulated. By analyzing the trend of operational parameters， the most energy-efficient operational scheme was obtained. A comparative analysis of the energy-saving operation schemes between the two processes revealed the technical advantages of the catalytic technology. The results showed that the catalytically-enhanced regeneration method effectively improved the desorption rate and the recycling amount of CO2 absorption. In terms of the energy consumption in processes， the catalytically-enhanced regeneration process reduced energy consumption by approximately 24% compared to conventional processes. The energy consumption cost could be reduced by approximately 43 RMB/t CO2. The results can provide essential technical support for developing low-energy consumption carbon capture technologies.
Under the background of national carbon peak and carbon neutrality in China，achieving low-cost and high-efficiency flue gas carbon capture is of great significance. As the most mature flue gas capture scheme， MEA absorption technology has been widely used in various industries carbon capture processes. The catalytically-enhanced regeneration method plays an important role in reducing the energy consumption in processes. In this work， by combining the process simulation approach in Aspen Plus， the conventional and catalytically-enhanced regeneration of MEA flue gas decarbonization processes were simulated and analyzed， aiming to clarify the technical advantages of the catalytically-enhanced regeneration method. Firstly， Aspen Plus was employed to simulate the conventional MEA flue gas decarbonization process， examining the impact of key operational parameters such as absorption temperature， gas-liquid ratio， and desorption temperature on the absorption efficiency. This analysis provided insights into the optimal operation of the MEA absorption and desorption processes， as well as an energy-efficient operational scheme. Secondly， by incorporating a catalytic hypothesis， a MEA decarbonization process with catalytically-enhanced regeneration was developed and simulated. By analyzing the trend of operational parameters， the most energy-efficient operational scheme was obtained. A comparative analysis of the energy-saving operation schemes between the two processes revealed the technical advantages of the catalytic technology. The results showed that the catalytically-enhanced regeneration method effectively improved the desorption rate and the recycling amount of CO2 absorption. In terms of the energy consumption in processes， the catalytically-enhanced regeneration process reduced energy consumption by approximately 24% compared to conventional processes. The energy consumption cost could be reduced by approximately 43 RMB/t CO2. The results can provide essential technical support for developing low-energy consumption carbon capture technologies.
2025,
43(9):
148-156.
doi: 10.13205/j.hjgc.202509016
Abstract:
The arid plateau regions， characterized by their unique climatic conditions such as intense ultraviolet radiation， low humidity， high wind speeds， and frequent sandstorms， impose extremely high demands on the durability and self-cleaning properties of materials. In recent years， catalytic self-cleaning materials have garnered significant attention due to their potential in environmental purification and energy efficiency enhancement. These materials achieve self-cleaning through photocatalytic reactions and their unique surface wettability properties. However， their traditional applications often rely on the presence of water， which somewhat limits their suitability in arid regions. To address this issue， this study employed a hydrothermal method to prepare a superhydrophilic titanium dioxide （TiO2） coating， with a focus on investigating its photocatalytic activity， UV resistance， and anti-static properties. Field tests were conducted in plateau arid regions to evaluate its performance. The experimental results demonstrated that the coating effectively removed contaminants from the surface of photovoltaic panels， significantly improving power generation efficiency. Specifically， the coating achieved a formaldehyde removal efficiency of up to 91.4% and an inhibition rate of 97.71% against Escherichia coli. In practical applications in southwestern regions， the power generation efficiency of photovoltaic systems increased by 4% to 6%， with a maximum improvement of 18.16%. In desert regions， the efficiency also saw an enhancement of 2.11%. These results clearly indicate that the catalytic self-cleaning coating exhibits excellent stability and durability under various environmental conditions， demonstrating broad application prospects.
The arid plateau regions， characterized by their unique climatic conditions such as intense ultraviolet radiation， low humidity， high wind speeds， and frequent sandstorms， impose extremely high demands on the durability and self-cleaning properties of materials. In recent years， catalytic self-cleaning materials have garnered significant attention due to their potential in environmental purification and energy efficiency enhancement. These materials achieve self-cleaning through photocatalytic reactions and their unique surface wettability properties. However， their traditional applications often rely on the presence of water， which somewhat limits their suitability in arid regions. To address this issue， this study employed a hydrothermal method to prepare a superhydrophilic titanium dioxide （TiO2） coating， with a focus on investigating its photocatalytic activity， UV resistance， and anti-static properties. Field tests were conducted in plateau arid regions to evaluate its performance. The experimental results demonstrated that the coating effectively removed contaminants from the surface of photovoltaic panels， significantly improving power generation efficiency. Specifically， the coating achieved a formaldehyde removal efficiency of up to 91.4% and an inhibition rate of 97.71% against Escherichia coli. In practical applications in southwestern regions， the power generation efficiency of photovoltaic systems increased by 4% to 6%， with a maximum improvement of 18.16%. In desert regions， the efficiency also saw an enhancement of 2.11%. These results clearly indicate that the catalytic self-cleaning coating exhibits excellent stability and durability under various environmental conditions， demonstrating broad application prospects.
2025,
43(9):
157-164.
doi: 10.13205/j.hjgc.202509017
Abstract:
China's Dual Carbon Goals have imposed stringent requirements on carbon emission reduction in the steel industry. The sintering process， a critical step in steel production， contributes up to 40% of the industry's total carbon emissions. Currently， chemical absorption is the predominant method for CO2 capture in industrial applications. However， research on chemical absorption for sintering flue gas， which is characterized by its complex composition， remains limited. Sintering flue gas typically contains lower CO2 concentrations and higher levels of impurities， such as SO2 and NO2， which significantly affect CO2 capture efficiency. Among these impurities， SO2 has a more pronounced impact than NO2 due to its higher reactivity with amine-based absorbents， leading to reduced absorption performance. To address these challenges， this study focused on developing high-efficiency CO2 absorbents tailored for sintering flue gas. The research began with an analysis of the composition of sintering flue gas from a representative sintering machine， revealing that the low CO2 concentration and the presence of SO2 and NO2 are critical factors influencing absorption efficiency. To investigate the CO2 absorption efficiency of different chemical absorbents for sintering flue gas， this study first determined the optimal process conditions by controlling the mass fraction of absorbents and temperature as single factors. Experiments identified the 30% MEA solution with the highest absorption efficiency as the primary amine. Subsequently， three binary composite solutions （MEA-MDEA， MEA-PZ， and MEA-K2CO3） and one ternary composite solution （MEA-PZ-MDEA） were adopted to analyze the CO2 absorption performance under different conditions.The results demonstrated that the CO2 absorption performance followed the order of MEA-PZ-MDEA > MEA-PZ > MEA-MDEA > MEA-K2CO3. The ternary blend （MEA-PZ-MDEA） exhibited the highest absorption efficiency， attributed to the synergistic effects of PZ's fast reaction kinetics and MDEA's low regeneration energy requirements. Additionally， the study highlights the importance of optimizing absorbent composition and operating conditions to mitigate the adverse effects of SO2 and NO2 on CO2 capture. It provides valuable insights into the development of advanced absorbents for sintering flue gas， offering a potential pathway for the steel industry to achieve significant carbon emission reductions. Future work should focus on scaling up the process and further improving the absorbents' resistance to impurities.
China's Dual Carbon Goals have imposed stringent requirements on carbon emission reduction in the steel industry. The sintering process， a critical step in steel production， contributes up to 40% of the industry's total carbon emissions. Currently， chemical absorption is the predominant method for CO2 capture in industrial applications. However， research on chemical absorption for sintering flue gas， which is characterized by its complex composition， remains limited. Sintering flue gas typically contains lower CO2 concentrations and higher levels of impurities， such as SO2 and NO2， which significantly affect CO2 capture efficiency. Among these impurities， SO2 has a more pronounced impact than NO2 due to its higher reactivity with amine-based absorbents， leading to reduced absorption performance. To address these challenges， this study focused on developing high-efficiency CO2 absorbents tailored for sintering flue gas. The research began with an analysis of the composition of sintering flue gas from a representative sintering machine， revealing that the low CO2 concentration and the presence of SO2 and NO2 are critical factors influencing absorption efficiency. To investigate the CO2 absorption efficiency of different chemical absorbents for sintering flue gas， this study first determined the optimal process conditions by controlling the mass fraction of absorbents and temperature as single factors. Experiments identified the 30% MEA solution with the highest absorption efficiency as the primary amine. Subsequently， three binary composite solutions （MEA-MDEA， MEA-PZ， and MEA-K2CO3） and one ternary composite solution （MEA-PZ-MDEA） were adopted to analyze the CO2 absorption performance under different conditions.The results demonstrated that the CO2 absorption performance followed the order of MEA-PZ-MDEA > MEA-PZ > MEA-MDEA > MEA-K2CO3. The ternary blend （MEA-PZ-MDEA） exhibited the highest absorption efficiency， attributed to the synergistic effects of PZ's fast reaction kinetics and MDEA's low regeneration energy requirements. Additionally， the study highlights the importance of optimizing absorbent composition and operating conditions to mitigate the adverse effects of SO2 and NO2 on CO2 capture. It provides valuable insights into the development of advanced absorbents for sintering flue gas， offering a potential pathway for the steel industry to achieve significant carbon emission reductions. Future work should focus on scaling up the process and further improving the absorbents' resistance to impurities.
2025,
43(9):
165-182.
doi: 10.13205/j.hjgc.202509018
Abstract:
Substantial quantities of organic waste are generated annually in rural areas of China， often being dispersed and poorly managed. Current waste treatment methods， including landfill， incineration， and composting， are faced with numerous challenges， such as low harmless treatment rates and inefficient resource utilization. The environment is not only harmed by these shortcomings， but a significant amount of valuable resources is also wasted as a result. Therefore， it is crucial to explore effective treatment methods for rural organic waste to improve resource utilization efficiency and foster sustainable waste management practices. This study focuses on exploring effective technologies for the treatment of rural organic waste， considering various types of waste and their specific characteristics. Anaerobic digestion， pyrolytic carbonization， and bioconversion are examined as promising solutions， especially for high-moisture rural waste such as fruits and vegetables. Additionally， for animal manure， the effectiveness of straw co-digestion and bioconversion is highlighted， as both methods are considered to significantly enhance resource recovery efficiency. These technologies are provided as viable alternatives to traditional disposal methods to improve waste management and promote environmental sustainability. Beyond technological approaches， various collection and treatment modes suitable for rural situations were investigated， including integrated urban-rural treatment， centralized processing， and dispersed treatment modes. The applicability of each mode was analyzed based on regional differences in waste generation， transportation infrastructure， and processing needs. The advantages and challenges of each mode of collection and transportation were highlighted in the study， emphasizing the importance of selecting an appropriate approach based on local conditions. It was suggested that rural areas with concentrated villages should adopt a centralized processing mode， while those with more dispersed settlements should implement a combination of dispersed and centralized treatment to enhance efficiency and sustainability. Through this strategic mode selection， waste management could be effectively adapted to local conditions and resource availability. This study reviewed the successful application of various business modes in waste incineration power generation projects， including public-private partnership （PPP）， build-operate-transfer （BOT）， and engineering procurement construction （EPC）. While these business modes have proven effective， further refinements in fiscal policies， tax incentives， and risk-sharing mechanisms are still required. Additionally， for pyrolytic carbonization projects， a multi-dimensional value chain approach is recommended to balance the complex interests of communities and the environment. Building on the experience of established business modes and considering the specific needs of rural organic waste treatment， a sustainable business mode is proposed. Collaboration among the government， enterprises， and rural communities is fostered by this business mode， ensuring that both the benefits and responsibilities of waste management and resource recovery are shared by all stakeholders. By incorporating value co-creation and feedback mechanisms， the business mode enhances adaptability， facilitating the successful adoption and stable operation of organic waste treatment technologies in rural areas.
Substantial quantities of organic waste are generated annually in rural areas of China， often being dispersed and poorly managed. Current waste treatment methods， including landfill， incineration， and composting， are faced with numerous challenges， such as low harmless treatment rates and inefficient resource utilization. The environment is not only harmed by these shortcomings， but a significant amount of valuable resources is also wasted as a result. Therefore， it is crucial to explore effective treatment methods for rural organic waste to improve resource utilization efficiency and foster sustainable waste management practices. This study focuses on exploring effective technologies for the treatment of rural organic waste， considering various types of waste and their specific characteristics. Anaerobic digestion， pyrolytic carbonization， and bioconversion are examined as promising solutions， especially for high-moisture rural waste such as fruits and vegetables. Additionally， for animal manure， the effectiveness of straw co-digestion and bioconversion is highlighted， as both methods are considered to significantly enhance resource recovery efficiency. These technologies are provided as viable alternatives to traditional disposal methods to improve waste management and promote environmental sustainability. Beyond technological approaches， various collection and treatment modes suitable for rural situations were investigated， including integrated urban-rural treatment， centralized processing， and dispersed treatment modes. The applicability of each mode was analyzed based on regional differences in waste generation， transportation infrastructure， and processing needs. The advantages and challenges of each mode of collection and transportation were highlighted in the study， emphasizing the importance of selecting an appropriate approach based on local conditions. It was suggested that rural areas with concentrated villages should adopt a centralized processing mode， while those with more dispersed settlements should implement a combination of dispersed and centralized treatment to enhance efficiency and sustainability. Through this strategic mode selection， waste management could be effectively adapted to local conditions and resource availability. This study reviewed the successful application of various business modes in waste incineration power generation projects， including public-private partnership （PPP）， build-operate-transfer （BOT）， and engineering procurement construction （EPC）. While these business modes have proven effective， further refinements in fiscal policies， tax incentives， and risk-sharing mechanisms are still required. Additionally， for pyrolytic carbonization projects， a multi-dimensional value chain approach is recommended to balance the complex interests of communities and the environment. Building on the experience of established business modes and considering the specific needs of rural organic waste treatment， a sustainable business mode is proposed. Collaboration among the government， enterprises， and rural communities is fostered by this business mode， ensuring that both the benefits and responsibilities of waste management and resource recovery are shared by all stakeholders. By incorporating value co-creation and feedback mechanisms， the business mode enhances adaptability， facilitating the successful adoption and stable operation of organic waste treatment technologies in rural areas.
2025,
43(9):
183-197.
doi: 10.13205/j.hjgc.202509019
Abstract:
With the rapid advancement of electric vehicles and energy storage systems， research on the recycling processes of spent lithium-ion batteries has become a critical focus for both academia and industry. Proper management of such processes is essential to address environmental challenges. This paper presents a comprehensive review of existing evaluation methods for the recycling of spent lithium-ion batteries， including life cycle assessment， techno-economic assessment， criticality assessment， material flow analysis， input-output analysis， best available technique evaluation， and the coupling of multiple methods. It evaluates the applicability， strengths， and limitations of each method while highlighting their differences in addressing battery chemistries， indicator selection， and model construction. Life cycle assessment is identified as the most widely applied and representative method due to its well-established evaluation framework and capacity to systematically assess environmental impacts. However， single-method approaches are insufficient to capture the intricate interdependencies among environmental， economic， and resource-related factors inherent in the recycling processes. Consequently， the integration of multiple evaluation methods has emerged as a significant research trend， allowing for a more comprehensive understanding of these multifaceted processes. Nevertheless， further advancements are required to enhance the coverage of multidimensional factors such as carbon emissions， resource utilization， environmental impacts， and economic benefits. The emergence of data-driven approaches， which incorporate machine learning techniques and big data analytics， offers new opportunities for addressing uncertainties， optimizing data processing， and improving model accuracy in the evaluation of recycling processes. This paper emphasizes the need for interdisciplinary methodologies and robust data frameworks to guide the sustainable development of the lithium-ion battery recycling industry. These findings can provide a scientific basis for optimizing recycling technologies， informing policy-making， and supporting the global transition to a circular economy.
With the rapid advancement of electric vehicles and energy storage systems， research on the recycling processes of spent lithium-ion batteries has become a critical focus for both academia and industry. Proper management of such processes is essential to address environmental challenges. This paper presents a comprehensive review of existing evaluation methods for the recycling of spent lithium-ion batteries， including life cycle assessment， techno-economic assessment， criticality assessment， material flow analysis， input-output analysis， best available technique evaluation， and the coupling of multiple methods. It evaluates the applicability， strengths， and limitations of each method while highlighting their differences in addressing battery chemistries， indicator selection， and model construction. Life cycle assessment is identified as the most widely applied and representative method due to its well-established evaluation framework and capacity to systematically assess environmental impacts. However， single-method approaches are insufficient to capture the intricate interdependencies among environmental， economic， and resource-related factors inherent in the recycling processes. Consequently， the integration of multiple evaluation methods has emerged as a significant research trend， allowing for a more comprehensive understanding of these multifaceted processes. Nevertheless， further advancements are required to enhance the coverage of multidimensional factors such as carbon emissions， resource utilization， environmental impacts， and economic benefits. The emergence of data-driven approaches， which incorporate machine learning techniques and big data analytics， offers new opportunities for addressing uncertainties， optimizing data processing， and improving model accuracy in the evaluation of recycling processes. This paper emphasizes the need for interdisciplinary methodologies and robust data frameworks to guide the sustainable development of the lithium-ion battery recycling industry. These findings can provide a scientific basis for optimizing recycling technologies， informing policy-making， and supporting the global transition to a circular economy.
2025,
43(9):
198-208.
doi: 10.13205/j.hjgc.202509020
Abstract:
The resource recovery of sewage sludge represents a key strategy for China to achieve both pollution reduction and carbon mitigation， as well as the circular utilization of resources. Serving as an “urban phosphorus mine，” sludge accumulates over 90% of the phosphorus present in wastewater， making it an important alternative source for the production of high-value-added phosphate products. This review systematically summarizes the technological routes and research progress for recovering phosphorus from sludge to produce battery-grade iron phosphate. First， the occurrence forms of phosphorus in sludge and their differences from phosphate ores are analyzed， highlighting the advantages of sludge-derived phosphorus in terms of source stability and lower radiological risk. Subsequently， the mechanisms， efficiency， and application potential of phosphorus release technologies—including biological， hydrometallurgical， electrochemical， and thermochemical methods—are compared. On this basis， the roles of purification processes such as ion exchange and membrane separation in enhancing phosphorus purity are discussed， along with the feasibility and specific pathways for producing battery-grade iron phosphate from different sludge sources （activated sludge， chemical sludge， mixed sludge， and incineration ash）. Finally， the comprehensive benefits and future development directions of this resource recovery route are examined. It is proposed that process integration， targeted impurity control， and full life-cycle assessment can facilitate the scale-up and industrial application of sludge-derived phosphorus recovery for battery-grade iron phosphate， offering new strategies for the high-value utilization of sewage sludge.
The resource recovery of sewage sludge represents a key strategy for China to achieve both pollution reduction and carbon mitigation， as well as the circular utilization of resources. Serving as an “urban phosphorus mine，” sludge accumulates over 90% of the phosphorus present in wastewater， making it an important alternative source for the production of high-value-added phosphate products. This review systematically summarizes the technological routes and research progress for recovering phosphorus from sludge to produce battery-grade iron phosphate. First， the occurrence forms of phosphorus in sludge and their differences from phosphate ores are analyzed， highlighting the advantages of sludge-derived phosphorus in terms of source stability and lower radiological risk. Subsequently， the mechanisms， efficiency， and application potential of phosphorus release technologies—including biological， hydrometallurgical， electrochemical， and thermochemical methods—are compared. On this basis， the roles of purification processes such as ion exchange and membrane separation in enhancing phosphorus purity are discussed， along with the feasibility and specific pathways for producing battery-grade iron phosphate from different sludge sources （activated sludge， chemical sludge， mixed sludge， and incineration ash）. Finally， the comprehensive benefits and future development directions of this resource recovery route are examined. It is proposed that process integration， targeted impurity control， and full life-cycle assessment can facilitate the scale-up and industrial application of sludge-derived phosphorus recovery for battery-grade iron phosphate， offering new strategies for the high-value utilization of sewage sludge.
2025,
43(9):
209-218.
doi: 10.13205/j.hjgc.202509021
Abstract:
The deep implementation of ultra-low emissions and the Double Carbon Goals in key industries， such as power and steel making has significantly altered the characteristics of flue gas from stationary sources， presenting new demands for stationary sources. This article discusses the current state of stationary sources in China and outlines the emerging technological demands for stationary sources monitoring under the background of pollution and carbon emissions reduction. Following ultra-low emission transformation， the concentrations of conventional pollutants such as dust， SO2， and NO x， as well as flue gas temperature， have decreased， while humidity of flue gas has increased in key industries. Meanwhile， the emission of unconventional pollutants， including condensable particulate matter （CPM）， NH3， organic amines， and greenhouse gases， has become increasingly prominent. Studies indicate that post-transformation CPM emissions account for 25.7% to 99.6% of total particulate matter， with some sources exhibiting CPM concentrations surpassing those of filterable particulate matter. Additionally， excessive ammonia injection in denitrification systems has led to significant ammonia slip， with substantial deviations observed among different NH3 monitoring methods. In coal-fired power plants undergoing low-carbon transformation， biomass co-firing may elevate the concentrations of particulate heavy metals and NH3 in flue gas. Furthermore， the use of organic amine absorbents in carbon capture processes can result in substantial organic amine emissions. As pollution and carbon reduction initiatives for stationary sources continue to advance， it is crucial to enhance the accuracy and quality control of online monitoring equipment for dust， SO2， and NO x. Additionally， a CPM monitoring technology tailored to China's stationary sources should be developed， and key industries should be systematically regulated. Ammonia emissions from stationary sources should be monitored using standardized methods， while online monitoring and control technologies for heavy metal emissions need further development. Additionally， online monitoring of organic amine escape from carbon capture processes should be implemented， and the development of carbon monitoring instruments should be strengthened.
The deep implementation of ultra-low emissions and the Double Carbon Goals in key industries， such as power and steel making has significantly altered the characteristics of flue gas from stationary sources， presenting new demands for stationary sources. This article discusses the current state of stationary sources in China and outlines the emerging technological demands for stationary sources monitoring under the background of pollution and carbon emissions reduction. Following ultra-low emission transformation， the concentrations of conventional pollutants such as dust， SO2， and NO x， as well as flue gas temperature， have decreased， while humidity of flue gas has increased in key industries. Meanwhile， the emission of unconventional pollutants， including condensable particulate matter （CPM）， NH3， organic amines， and greenhouse gases， has become increasingly prominent. Studies indicate that post-transformation CPM emissions account for 25.7% to 99.6% of total particulate matter， with some sources exhibiting CPM concentrations surpassing those of filterable particulate matter. Additionally， excessive ammonia injection in denitrification systems has led to significant ammonia slip， with substantial deviations observed among different NH3 monitoring methods. In coal-fired power plants undergoing low-carbon transformation， biomass co-firing may elevate the concentrations of particulate heavy metals and NH3 in flue gas. Furthermore， the use of organic amine absorbents in carbon capture processes can result in substantial organic amine emissions. As pollution and carbon reduction initiatives for stationary sources continue to advance， it is crucial to enhance the accuracy and quality control of online monitoring equipment for dust， SO2， and NO x. Additionally， a CPM monitoring technology tailored to China's stationary sources should be developed， and key industries should be systematically regulated. Ammonia emissions from stationary sources should be monitored using standardized methods， while online monitoring and control technologies for heavy metal emissions need further development. Additionally， online monitoring of organic amine escape from carbon capture processes should be implemented， and the development of carbon monitoring instruments should be strengthened.
2025,
43(9):
219-230.
doi: 10.13205/j.hjgc.202509022
Abstract:
The research hotspot analysis of sewage sludge treatment technologies was carried out to provide a basis for the construction of an urban sewage sludge green and low-carbon treatment technology library. Then， a technology evaluation index system was constructed according to the characteristics and needs of the Yangtze River Basin， and the technologies in the library were evaluated using the AHP-TOPSIS （analytic hierarchy process-technique for order of preference by similarity to ideal solution） method. Forty-six green and low-carbon treatment technologies for urban sewage sludge in the Yangtze River Basin were screened out， and seven excellent technologies with application cases were analyzed. The results show that excellent sewage treatment technologies exhibit similar performance in indicators such as COD and TP reduction rates， carbon emission intensity， etc.， but differ in advancedness， TN reduction rate， investment and construction costs. Some technologies still have room for improvement and upgrading. For residual sludge treatment， excellent technologies show similar levels in advancedness， applicability， and investment and construction costs， but significant differences exist in indicators such as dewatering rate and the land area occupied by sludge treatment. The technical evaluation results show that： A2O and oxidation ditch are the best for sewage treatment， MBR， artificial wetland comes second； the anaerobic digestion process is optimal in sludge treatment， followed by aerobic composting and sludge dewatering. The research results can provide technical references for pollution reduction and carbon emission synergies in urban sewage treatment plants in the Yangtze River Basin.
The research hotspot analysis of sewage sludge treatment technologies was carried out to provide a basis for the construction of an urban sewage sludge green and low-carbon treatment technology library. Then， a technology evaluation index system was constructed according to the characteristics and needs of the Yangtze River Basin， and the technologies in the library were evaluated using the AHP-TOPSIS （analytic hierarchy process-technique for order of preference by similarity to ideal solution） method. Forty-six green and low-carbon treatment technologies for urban sewage sludge in the Yangtze River Basin were screened out， and seven excellent technologies with application cases were analyzed. The results show that excellent sewage treatment technologies exhibit similar performance in indicators such as COD and TP reduction rates， carbon emission intensity， etc.， but differ in advancedness， TN reduction rate， investment and construction costs. Some technologies still have room for improvement and upgrading. For residual sludge treatment， excellent technologies show similar levels in advancedness， applicability， and investment and construction costs， but significant differences exist in indicators such as dewatering rate and the land area occupied by sludge treatment. The technical evaluation results show that： A2O and oxidation ditch are the best for sewage treatment， MBR， artificial wetland comes second； the anaerobic digestion process is optimal in sludge treatment， followed by aerobic composting and sludge dewatering. The research results can provide technical references for pollution reduction and carbon emission synergies in urban sewage treatment plants in the Yangtze River Basin.
