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2026, Volume 44, Issue 6
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2026,
44(6):
1-9.
doi: 10.13205/j.hjgc.202606001
Abstract:
The efficiency of recovering resources from municipal sludge through anaerobic processes is generally lower in China than in developed countries. The widespread adoption of chemical phosphorus removal processes has increased the content of chemical precipitates （e.g.， iron and aluminum salts） in waste activated sludge， resulting in the formation of chemical-biological sewage sludge that reduces acidogenic efficiency during anaerobic fermentation. This study aims to identify the key factors affecting the acidogenic performance in such sludge and to develop a high-precision prediction model to facilitate its resource recovery. By integrating literature and experimental data， acidogenic performance indicators under various anaerobic fermentation conditions were obtained. The predictive capabilities of five machine learning models—Backpropagation Neural Network， Adaptive Neuro-Fuzzy Inference System， Support Vector Machine， K-Nearest Neighbors， and Random Forest —were systematically compared， and feature importance was analyzed using the optimal model. The results indicated that the Random Forest model achieved the best predictive performance， with a coefficient of determination as high as 0.9463 on the test set， significantly outperforming the other models while exhibiting minimal overfitting risk. This demonstrated its strong capability in handling the high-dimensional， nonlinear， and multi-factor coupled problems like anaerobic fermentation. Feature importance analysis based on this model revealed that pH and Volatile Suspended Solids （VSS） were the primary drivers of acidogenic efficiency， with the effect of aluminum salts being greater than that of iron salts. Consequently， for engineering applications， process optimization should follow the pathway of "adjusting pH， stabilizing organic matter content， and controlling aluminum salts". This study not only provides an intelligent predictive tool for the efficient resource recovery of chemical-biological hybrid sludge but also clarifies specific directions for process optimization， holding significant importance for promoting the precision and intelligent development of sludge treatment technology.
The efficiency of recovering resources from municipal sludge through anaerobic processes is generally lower in China than in developed countries. The widespread adoption of chemical phosphorus removal processes has increased the content of chemical precipitates （e.g.， iron and aluminum salts） in waste activated sludge， resulting in the formation of chemical-biological sewage sludge that reduces acidogenic efficiency during anaerobic fermentation. This study aims to identify the key factors affecting the acidogenic performance in such sludge and to develop a high-precision prediction model to facilitate its resource recovery. By integrating literature and experimental data， acidogenic performance indicators under various anaerobic fermentation conditions were obtained. The predictive capabilities of five machine learning models—Backpropagation Neural Network， Adaptive Neuro-Fuzzy Inference System， Support Vector Machine， K-Nearest Neighbors， and Random Forest —were systematically compared， and feature importance was analyzed using the optimal model. The results indicated that the Random Forest model achieved the best predictive performance， with a coefficient of determination as high as 0.9463 on the test set， significantly outperforming the other models while exhibiting minimal overfitting risk. This demonstrated its strong capability in handling the high-dimensional， nonlinear， and multi-factor coupled problems like anaerobic fermentation. Feature importance analysis based on this model revealed that pH and Volatile Suspended Solids （VSS） were the primary drivers of acidogenic efficiency， with the effect of aluminum salts being greater than that of iron salts. Consequently， for engineering applications， process optimization should follow the pathway of "adjusting pH， stabilizing organic matter content， and controlling aluminum salts". This study not only provides an intelligent predictive tool for the efficient resource recovery of chemical-biological hybrid sludge but also clarifies specific directions for process optimization， holding significant importance for promoting the precision and intelligent development of sludge treatment technology.
2026,
44(6):
10-19.
doi: 10.13205/j.hjgc.202606002
Abstract:
Efficient reduction of industrial volatile organic compounds （VOCs） emissions is a key path to improving regional air quality. Taking the rubber paste preparation workshop， a typical process unit in the rubber industry， as the research object， this study designed and developed an intelligent monitoring system integrating software engineering and Internet of Things （IoT） technology. The core technical architecture of the system integrates a hybrid database storage solution， low-power wide-area IoT communication technology， a role-based access control model， and a containerized microservice architecture， effectively solving the problems of heterogeneous data fusion difficulties and insufficient scalability in traditional industrial monitoring systems. The system was deployed in a large rubber enterprise. By establishing a dynamic data list covering the whole process of VOCs exhaust gas collection-purification treatment-end-of-line emission， real-time perception and data fusion analysis of the operation status of the adsorption/desorption centrifugal fan were achieved. Under typical working conditions， the volume flow rate of the extraction system was 40000 m3/h， and that of the ventilation system was 30000 m3/h， forming a continuous micro-negative pressure environment that effectively suppressed unorganized emissions. The workshop purification process effectively reduced the concentration of non-methane hydrocarbon emissions to less than 10 mg/m3， which met the emission control standards. The system innovatively coupled the permission management module with the enterprise organizational structure to achieve precise division of operation permissions for production， environmental protection， and management roles， significantly reducing the response time for abnormal conditions. Based on the enterprise's "zeolite rotor adsorption concentration + regenerative thermal catalytic oxidation" purification process， an online evaluation model for purification efficiency was constructed. The "data-driven decision-making-intelligent dynamic regulation-precise responsibility traceability" technical paradigm established in this study provides a reusable framework for the application of computer technology in the deep treatment of industrial VOCs. It also has important practical value for promoting the intelligent management of pollutants throughout the process of typical industrial parks， and is especially applicable to rubber products sectors with dense solvent usage， such as tire manufacturing and sealing component production.
Efficient reduction of industrial volatile organic compounds （VOCs） emissions is a key path to improving regional air quality. Taking the rubber paste preparation workshop， a typical process unit in the rubber industry， as the research object， this study designed and developed an intelligent monitoring system integrating software engineering and Internet of Things （IoT） technology. The core technical architecture of the system integrates a hybrid database storage solution， low-power wide-area IoT communication technology， a role-based access control model， and a containerized microservice architecture， effectively solving the problems of heterogeneous data fusion difficulties and insufficient scalability in traditional industrial monitoring systems. The system was deployed in a large rubber enterprise. By establishing a dynamic data list covering the whole process of VOCs exhaust gas collection-purification treatment-end-of-line emission， real-time perception and data fusion analysis of the operation status of the adsorption/desorption centrifugal fan were achieved. Under typical working conditions， the volume flow rate of the extraction system was 40000 m3/h， and that of the ventilation system was 30000 m3/h， forming a continuous micro-negative pressure environment that effectively suppressed unorganized emissions. The workshop purification process effectively reduced the concentration of non-methane hydrocarbon emissions to less than 10 mg/m3， which met the emission control standards. The system innovatively coupled the permission management module with the enterprise organizational structure to achieve precise division of operation permissions for production， environmental protection， and management roles， significantly reducing the response time for abnormal conditions. Based on the enterprise's "zeolite rotor adsorption concentration + regenerative thermal catalytic oxidation" purification process， an online evaluation model for purification efficiency was constructed. The "data-driven decision-making-intelligent dynamic regulation-precise responsibility traceability" technical paradigm established in this study provides a reusable framework for the application of computer technology in the deep treatment of industrial VOCs. It also has important practical value for promoting the intelligent management of pollutants throughout the process of typical industrial parks， and is especially applicable to rubber products sectors with dense solvent usage， such as tire manufacturing and sealing component production.
2026,
44(6):
20-29.
doi: 10.13205/j.hjgc.202606003
Abstract:
Membrane separation technology， characterized by its superior separation efficiency， inherently low energy footprint， and exceptional operational flexibility， has emerged as a compelling and sustainable solution for the strategic recovery of lithium. Despite its immense potential， the precise and selective extraction of lithium ions from multifaceted and chemically demanding matrices， such as hypersaline salt lake brines and highly acidic spent battery leachates， encounters formidable technical bottlenecks that are difficult to overcome using conventional means. Traditional membrane development paradigms are increasingly hindered by the inherent inefficiencies of empirical trial-and-error approaches and the deep-seated difficulty in achieving a synergistic optimization of competing performance metrics， particularly the pervasive permeability-selectivity trade-off. To systematically address these limitations， this review provides a comprehensive delineation of cutting-edge machine learning （ML）-based frameworks. These methodologies encompass the high-throughput rational screening of high-performance membrane materials， the complex inverse design of synthesis protocols， and the high-fidelity prediction of multi-stage separation performance under diverse conditions. The review further elucidates the pivotal role of advanced ML algorithms in deciphering intricate structure-activity relationships at the molecular level， surmounting historical performance ceilings， and providing transformative， data-driven guidance for the bottom-up fabrication of next-generation functional membranes. Furthermore， the review critically assesses the prevailing challenges within this rapidly evolving interdisciplinary nexus， notably the acute paucity of high-quality standardized datasets， the persistent nature of model interpretability， and the restricted generalizability of laboratory-scale models across complex industrial landscapes. Finally， strategic future research trajectories are proposed， emphasizing the integration of physics-informed hybrid intelligent models， the establishment of robust open-source global databases， and the implementation of holistic， full-process system optimizations. These advancements are essential to bridging the current gap between laboratory-scale innovation and the large-scale industrial deployment of ML-based lithium recovery technologies.
Membrane separation technology， characterized by its superior separation efficiency， inherently low energy footprint， and exceptional operational flexibility， has emerged as a compelling and sustainable solution for the strategic recovery of lithium. Despite its immense potential， the precise and selective extraction of lithium ions from multifaceted and chemically demanding matrices， such as hypersaline salt lake brines and highly acidic spent battery leachates， encounters formidable technical bottlenecks that are difficult to overcome using conventional means. Traditional membrane development paradigms are increasingly hindered by the inherent inefficiencies of empirical trial-and-error approaches and the deep-seated difficulty in achieving a synergistic optimization of competing performance metrics， particularly the pervasive permeability-selectivity trade-off. To systematically address these limitations， this review provides a comprehensive delineation of cutting-edge machine learning （ML）-based frameworks. These methodologies encompass the high-throughput rational screening of high-performance membrane materials， the complex inverse design of synthesis protocols， and the high-fidelity prediction of multi-stage separation performance under diverse conditions. The review further elucidates the pivotal role of advanced ML algorithms in deciphering intricate structure-activity relationships at the molecular level， surmounting historical performance ceilings， and providing transformative， data-driven guidance for the bottom-up fabrication of next-generation functional membranes. Furthermore， the review critically assesses the prevailing challenges within this rapidly evolving interdisciplinary nexus， notably the acute paucity of high-quality standardized datasets， the persistent nature of model interpretability， and the restricted generalizability of laboratory-scale models across complex industrial landscapes. Finally， strategic future research trajectories are proposed， emphasizing the integration of physics-informed hybrid intelligent models， the establishment of robust open-source global databases， and the implementation of holistic， full-process system optimizations. These advancements are essential to bridging the current gap between laboratory-scale innovation and the large-scale industrial deployment of ML-based lithium recovery technologies.
2026,
44(6):
30-41.
doi: 10.13205/j.hjgc.202606004
Abstract:
To identify optimal watershed remediation pathways under environmental and economic dimensions， an integrated environmental-economic impact assessment framework combining life cycle assessment （LCA） and life cycle costing （LCC） based on open LCA was established， using 1 m3 of treated wastewater as the functional unit. This framework comprehensively evaluated the environmental impacts and economic costs of three ecological buffer measures—constructed wetlands， ecological intercepting ditches， and vegetation restoration projects—in non-point source pollution control. The results indicated that constructed wetlands offer the optimal environmental-economic profile， featuring the lowest comprehensive cost （¥ 1.01 yuan/m3） and the lowest load across most environmental impact categories， with only slightly higher land resource consumption intensity. Ecological intercepting ditches exhibited higher impacts in areas such as metal resource consumption due to the use of rebars and base fertilizer inputs， resulting in a moderate comprehensive cost （¥ 1.57 yuan/m3）. Vegetation restoration projects incurred the highest comprehensive cost （¥ 61.14 yuan/m3） and produced the most significant environmental impacts， with elevated indicators such as human carcinogenic toxicity. This primarily stemmed from the extensive use of concrete grass pavers and base fertilizer in rural river sections. These findings provide quantitative references for environmental-economic integrated evaluation and decision-making regarding ecological buffer zone engineering schemes in similar watersheds.
To identify optimal watershed remediation pathways under environmental and economic dimensions， an integrated environmental-economic impact assessment framework combining life cycle assessment （LCA） and life cycle costing （LCC） based on open LCA was established， using 1 m3 of treated wastewater as the functional unit. This framework comprehensively evaluated the environmental impacts and economic costs of three ecological buffer measures—constructed wetlands， ecological intercepting ditches， and vegetation restoration projects—in non-point source pollution control. The results indicated that constructed wetlands offer the optimal environmental-economic profile， featuring the lowest comprehensive cost （¥ 1.01 yuan/m3） and the lowest load across most environmental impact categories， with only slightly higher land resource consumption intensity. Ecological intercepting ditches exhibited higher impacts in areas such as metal resource consumption due to the use of rebars and base fertilizer inputs， resulting in a moderate comprehensive cost （¥ 1.57 yuan/m3）. Vegetation restoration projects incurred the highest comprehensive cost （¥ 61.14 yuan/m3） and produced the most significant environmental impacts， with elevated indicators such as human carcinogenic toxicity. This primarily stemmed from the extensive use of concrete grass pavers and base fertilizer in rural river sections. These findings provide quantitative references for environmental-economic integrated evaluation and decision-making regarding ecological buffer zone engineering schemes in similar watersheds.
2026,
44(6):
42-49.
doi: 10.13205/j.hjgc.202606005
Abstract:
In the context of carbon peaking and carbon neutrality， it is imperative that urban reclaimed water plants achieve carbon neutrality through measures such as energy conservation， consumption reduction， and enhanced resource and energy utilization. In view of this， this study developed a carbon emission balance model and an accounting method for such plants， incorporating strategies of carbon emission reduction， carbon substitution， and carbon sink. Additionally， the optimal pathway towards carbon neutrality was further evaluated based on the carbon emission balance ratio. To validate the practicality of the model， urban reclaimed water plants （1×105 m3/d） were selected as case studies. The results indicated that their total carbon emissions amounted to 20934 t CO2e， while the total carbon emission reduction from the reclaimed water source heat pumps for heating and cooling was 21701 t CO2e， resulting in a carbon emission balance ratio of 103.7%. In contrast， other carbon emission reduction measures contributed a total reduction of 15424 t CO2e， with a carbon emission balance ratio of 73.7%. These findings highlighted that reclaimed water source heat pumps played a pivotal role in achieving carbon neutrality. When the reclaimed water source heat pump extracted 27% and 36% of residual thermal energy and was respectively coupled with reclaimed water reuse or sludge anaerobic digestion-cogeneration systems， both pathways achieved a 100% carbon emission balance ratio. Assuming continuous year-round extraction of residual thermal energy by the pump， a ratio of 213% was achieved. Compared to sludge anaerobic digestion-cogeneration， the carbon emission reduction ratio between utilizing residual thermal energy and chemical energy was 8.76：1. This study demonstrates that urban reclaimed water plants can achieve carbon neutrality through the above multiple pathways， among which the recovery of residual thermal energy exhibits significant potential.
In the context of carbon peaking and carbon neutrality， it is imperative that urban reclaimed water plants achieve carbon neutrality through measures such as energy conservation， consumption reduction， and enhanced resource and energy utilization. In view of this， this study developed a carbon emission balance model and an accounting method for such plants， incorporating strategies of carbon emission reduction， carbon substitution， and carbon sink. Additionally， the optimal pathway towards carbon neutrality was further evaluated based on the carbon emission balance ratio. To validate the practicality of the model， urban reclaimed water plants （1×105 m3/d） were selected as case studies. The results indicated that their total carbon emissions amounted to 20934 t CO2e， while the total carbon emission reduction from the reclaimed water source heat pumps for heating and cooling was 21701 t CO2e， resulting in a carbon emission balance ratio of 103.7%. In contrast， other carbon emission reduction measures contributed a total reduction of 15424 t CO2e， with a carbon emission balance ratio of 73.7%. These findings highlighted that reclaimed water source heat pumps played a pivotal role in achieving carbon neutrality. When the reclaimed water source heat pump extracted 27% and 36% of residual thermal energy and was respectively coupled with reclaimed water reuse or sludge anaerobic digestion-cogeneration systems， both pathways achieved a 100% carbon emission balance ratio. Assuming continuous year-round extraction of residual thermal energy by the pump， a ratio of 213% was achieved. Compared to sludge anaerobic digestion-cogeneration， the carbon emission reduction ratio between utilizing residual thermal energy and chemical energy was 8.76：1. This study demonstrates that urban reclaimed water plants can achieve carbon neutrality through the above multiple pathways， among which the recovery of residual thermal energy exhibits significant potential.
2026,
44(6):
50-59.
doi: 10.13205/j.hjgc.202606006
Abstract:
Chitosan-based microsphere composites have garnered significant attention in phosphorus adsorption due to their easy preparation， low cost， eco-friendliness， and high phosphorus uptake capacity. This review summarized the physicochemical properties and preparation methods of chitosan-based microspheres for phosphorus removal， outlined common modification strategies to enhance their phosphorus adsorption capacity， and discussed their current applications in phosphate removal from aqueous environments. The adsorption mechanisms were analyzed， along with the regeneration and resource recovery of spent microspheres. Finally， this review highlighted existing research challenges and proposed recommendations including streamlined preparation methods， enhanced phosphorus recovery， removal of multiple phosphorus forms， and practical implementation， to guide the development of high-performance chitosan-based microspheres for phosphorus removal.
Chitosan-based microsphere composites have garnered significant attention in phosphorus adsorption due to their easy preparation， low cost， eco-friendliness， and high phosphorus uptake capacity. This review summarized the physicochemical properties and preparation methods of chitosan-based microspheres for phosphorus removal， outlined common modification strategies to enhance their phosphorus adsorption capacity， and discussed their current applications in phosphate removal from aqueous environments. The adsorption mechanisms were analyzed， along with the regeneration and resource recovery of spent microspheres. Finally， this review highlighted existing research challenges and proposed recommendations including streamlined preparation methods， enhanced phosphorus recovery， removal of multiple phosphorus forms， and practical implementation， to guide the development of high-performance chitosan-based microspheres for phosphorus removal.
2026,
44(6):
60-71.
doi: 10.13205/j.hjgc.202606007
Abstract:
Spinel metal oxides derived from cobalt-aluminum hydrotalcite were synthesized using hydrothermal， coprecipitation， and sol-gel methods， and their performance in catalytic NO oxidation was studied. The outcomes derived from X-ray photoelectron spectroscopy （XPS）， O2 temperature-programmed desorption （O2-TPD）， H2 temperature-programmed reduction （H2-TPR）， and Raman spectroscopy collectively demonstrate that disparate synthesis methodologies exert a substantial impact on the surface Co2+/Co3+ ratio of the catalyst， which in turn modulates the formation of surface oxygen vacancies. Compared with coprecipitation and sol-gel methods， the catalysts synthesized through the hydrothermal method exhibit a superior density of surface oxygen vacancies. This enhanced vacancy density confers a heightened capacity for the adsorption and activation of gaseous oxygen molecules， culminating in the most effective NO oxidation performance among the examined catalysts. Additionally， NO temperature-programmed desorption （NO-TPD）， NO+O2 temperature-programmed desorption （NO+O2-TPD）， and in situ diffuse reflectance infrared Fourier transform spectroscopy （in situ DRIFTS） indicate that nitrates are the key intermediates for NO oxidation to NO2 on these catalysts， primarily following the Langmuir-Hinshelwood （L-H） reaction mechanism.
Spinel metal oxides derived from cobalt-aluminum hydrotalcite were synthesized using hydrothermal， coprecipitation， and sol-gel methods， and their performance in catalytic NO oxidation was studied. The outcomes derived from X-ray photoelectron spectroscopy （XPS）， O2 temperature-programmed desorption （O2-TPD）， H2 temperature-programmed reduction （H2-TPR）， and Raman spectroscopy collectively demonstrate that disparate synthesis methodologies exert a substantial impact on the surface Co2+/Co3+ ratio of the catalyst， which in turn modulates the formation of surface oxygen vacancies. Compared with coprecipitation and sol-gel methods， the catalysts synthesized through the hydrothermal method exhibit a superior density of surface oxygen vacancies. This enhanced vacancy density confers a heightened capacity for the adsorption and activation of gaseous oxygen molecules， culminating in the most effective NO oxidation performance among the examined catalysts. Additionally， NO temperature-programmed desorption （NO-TPD）， NO+O2 temperature-programmed desorption （NO+O2-TPD）， and in situ diffuse reflectance infrared Fourier transform spectroscopy （in situ DRIFTS） indicate that nitrates are the key intermediates for NO oxidation to NO2 on these catalysts， primarily following the Langmuir-Hinshelwood （L-H） reaction mechanism.
2026,
44(6):
72-83.
doi: 10.13205/j.hjgc.202606008
Abstract:
Resin-enhanced electrosorption for water treatment significantly improves ion adsorption efficiency and selectivity through synergistic effects， making it a research hotspot in the water treatment field. This technology provides an innovative solution to the bottlenecks of kinetic lag and insufficient selectivity by modulating electrode-solution interface behavior in multiple dimensions. Current technological advances include the following： a simple integration method enables desalination efficiency to exceed 92.3%； resin-coated composite electrodes eliminate the co-ion effect and achieve a 42% increase in total salt adsorption capacity； resin-derived porous carbon electrodes with tunable pore structures possess three to five times the adsorption capacity of commercially available activated carbon； and by enhancing solution convection and electrophoretic convection， the resin-filling strategy achieves a high desalination rate of （670 ± 20） mg/（L·h）. Studies have demonstrated that different material combinations can achieve targeted optimization of adsorption performance based on specific water quality characteristics. Future research directions may focus on： developing intelligent resin materials with electromagnetic responsiveness； constructing a multi-scale structural design theory for resin-electrode systems； and establishing a cross-scale model integrating electrochemistry， fluid dynamics， and interface science for comprehensive analysis. In particular， in-depth studies are needed on the dynamic behavior of resin-based flow electrodes under electric/magnetic field regulation， as well as the precise construction of catalytic sites on the resin surface. This review aims to promote the widespread application and efficient practice of this technology in water treatment， providing a theoretical foundation and scientific basis for the future development of high-efficiency， selective， and stable electrosorption technologies.
Resin-enhanced electrosorption for water treatment significantly improves ion adsorption efficiency and selectivity through synergistic effects， making it a research hotspot in the water treatment field. This technology provides an innovative solution to the bottlenecks of kinetic lag and insufficient selectivity by modulating electrode-solution interface behavior in multiple dimensions. Current technological advances include the following： a simple integration method enables desalination efficiency to exceed 92.3%； resin-coated composite electrodes eliminate the co-ion effect and achieve a 42% increase in total salt adsorption capacity； resin-derived porous carbon electrodes with tunable pore structures possess three to five times the adsorption capacity of commercially available activated carbon； and by enhancing solution convection and electrophoretic convection， the resin-filling strategy achieves a high desalination rate of （670 ± 20） mg/（L·h）. Studies have demonstrated that different material combinations can achieve targeted optimization of adsorption performance based on specific water quality characteristics. Future research directions may focus on： developing intelligent resin materials with electromagnetic responsiveness； constructing a multi-scale structural design theory for resin-electrode systems； and establishing a cross-scale model integrating electrochemistry， fluid dynamics， and interface science for comprehensive analysis. In particular， in-depth studies are needed on the dynamic behavior of resin-based flow electrodes under electric/magnetic field regulation， as well as the precise construction of catalytic sites on the resin surface. This review aims to promote the widespread application and efficient practice of this technology in water treatment， providing a theoretical foundation and scientific basis for the future development of high-efficiency， selective， and stable electrosorption technologies.
2026,
44(6):
84-91.
doi: 10.13205/j.hjgc.202606009
Abstract:
With China's rapid economic and urban growth， the amount of domestic waste is increasing annually. Effective disposal of domestic waste has become a research focus. Collaborative disposal of domestic waste in industrial kilns is an effective treatment method； however， high temperature generates Cl2 and HCl gases， which cause equipment corrosion and reduce service life. High-temperature dechlorination is thus crucial for controlling chlorine release， minimizing equipment damage， and enhancing co-processing efficiency and safety. In this study， fly ash and red mud were selected as the primary raw materials to investigate their potential for dechlorination at high temperatures. Fly ash， a by-product of coal combustion， and red mud， a residue from alumina production， are abundant solid wastes that can potentially be utilized for this purpose. The results showed that at 700 ℃， fly ash achieved a dechlorination efficiency of 93.33%， while red mud achieved 88.61%. These findings suggest that both materials have considerable potential for dechlorination. However， as the temperature increased， the dechlorination efficiency of both materials declined. To address this issue and optimize the dechlorination efficiency of fly ash， modification studies were conducted. The results indicated that alkali-modified fly ash significantly improved its dechlorination efficiency. Specifically， at 800 ℃， the dechlorination efficiency of alkali-modified fly ash increased from 71.9% to 94.98%. This suggests that alkali modification enhances the dechlorination capability of fly ash and enables more effective adsorption of HCl gas. Overall， this study not only verifies the feasibility of using solid waste as a dechlorination agent but also opens up new avenues for the resource utilization of solid waste. By repurposing fly ash and red mud for high-temperature dechlorination， this study contributes to more sustainable waste management practices and reduces the environmental footprint of industrial processes.
With China's rapid economic and urban growth， the amount of domestic waste is increasing annually. Effective disposal of domestic waste has become a research focus. Collaborative disposal of domestic waste in industrial kilns is an effective treatment method； however， high temperature generates Cl2 and HCl gases， which cause equipment corrosion and reduce service life. High-temperature dechlorination is thus crucial for controlling chlorine release， minimizing equipment damage， and enhancing co-processing efficiency and safety. In this study， fly ash and red mud were selected as the primary raw materials to investigate their potential for dechlorination at high temperatures. Fly ash， a by-product of coal combustion， and red mud， a residue from alumina production， are abundant solid wastes that can potentially be utilized for this purpose. The results showed that at 700 ℃， fly ash achieved a dechlorination efficiency of 93.33%， while red mud achieved 88.61%. These findings suggest that both materials have considerable potential for dechlorination. However， as the temperature increased， the dechlorination efficiency of both materials declined. To address this issue and optimize the dechlorination efficiency of fly ash， modification studies were conducted. The results indicated that alkali-modified fly ash significantly improved its dechlorination efficiency. Specifically， at 800 ℃， the dechlorination efficiency of alkali-modified fly ash increased from 71.9% to 94.98%. This suggests that alkali modification enhances the dechlorination capability of fly ash and enables more effective adsorption of HCl gas. Overall， this study not only verifies the feasibility of using solid waste as a dechlorination agent but also opens up new avenues for the resource utilization of solid waste. By repurposing fly ash and red mud for high-temperature dechlorination， this study contributes to more sustainable waste management practices and reduces the environmental footprint of industrial processes.
2026,
44(6):
92-100.
doi: 10.13205/j.hjgc.202606010
Abstract:
Dissolved oxygen （DO） is crucial in controlling the migration of endogenous phosphorus in eutrophic waters. Current oxygenation technologies face issues such as high energy consumption and disturbance of sediments. Therefore， there is an urgent need to explore low-disturbance， pH-stable oxygenation strategies that do not introduce additional nitrogen and phosphorus loads， as well as their mechanisms for phosphorus inhibition. In this study， laboratory microcosm experiments were conducted using natural samples from eutrophic waters， DO microprofiles across the sediment-water interface were determined using microelectrodes， while diffusive gradients in thin films （DGT） were used to characterize the concentrations and spatial distributions of Fe， S， and P at the interface. In addition， a sequential extraction procedure was employed to quantify changes in different phosphorus fractions in the sediment. The results showed that after covering with the oxygen-loaded porous material， the DO concentration in the surface sediment increased by 6.58 times， the DO penetration depth increased by 1.33 times， the total phosphorus （TP） concentration in the overlying water decreased by 93.79%， and the phosphate （PO3-4-P） in the sediment interstitial water decreased by up to 45.75%. The sediment-water interface TP exchange flux changed from 0.0068 mg/（m2·d） to -0.014 mg/（m2·d） ， shifting from a phosphorus source to a phosphorus sink. In the sediments， the stable phosphorus form （Res-P） increased by 5.22%， while the labile phosphorus form （NaHCO3-P） decreased by 4.48%. Consequently， through coupling of redox-sensitive elements iron and sulfur， the immobilization of phosphorus in sediments was enhanced， reducing the release of endogenous phosphorus. The oxygen-loaded porous material inhibited phosphorus release from sediments by regulating interfacial dissolved oxygen， providing a theoretical basis for the scientific study of endogenous phosphorus control in eutrophic waters without altering pH conditions.
Dissolved oxygen （DO） is crucial in controlling the migration of endogenous phosphorus in eutrophic waters. Current oxygenation technologies face issues such as high energy consumption and disturbance of sediments. Therefore， there is an urgent need to explore low-disturbance， pH-stable oxygenation strategies that do not introduce additional nitrogen and phosphorus loads， as well as their mechanisms for phosphorus inhibition. In this study， laboratory microcosm experiments were conducted using natural samples from eutrophic waters， DO microprofiles across the sediment-water interface were determined using microelectrodes， while diffusive gradients in thin films （DGT） were used to characterize the concentrations and spatial distributions of Fe， S， and P at the interface. In addition， a sequential extraction procedure was employed to quantify changes in different phosphorus fractions in the sediment. The results showed that after covering with the oxygen-loaded porous material， the DO concentration in the surface sediment increased by 6.58 times， the DO penetration depth increased by 1.33 times， the total phosphorus （TP） concentration in the overlying water decreased by 93.79%， and the phosphate （PO3-4-P） in the sediment interstitial water decreased by up to 45.75%. The sediment-water interface TP exchange flux changed from 0.0068 mg/（m2·d） to -0.014 mg/（m2·d） ， shifting from a phosphorus source to a phosphorus sink. In the sediments， the stable phosphorus form （Res-P） increased by 5.22%， while the labile phosphorus form （NaHCO3-P） decreased by 4.48%. Consequently， through coupling of redox-sensitive elements iron and sulfur， the immobilization of phosphorus in sediments was enhanced， reducing the release of endogenous phosphorus. The oxygen-loaded porous material inhibited phosphorus release from sediments by regulating interfacial dissolved oxygen， providing a theoretical basis for the scientific study of endogenous phosphorus control in eutrophic waters without altering pH conditions.
2026,
44(6):
101-112.
doi: 10.13205/j.hjgc.202606011
Abstract:
To address the remediation of hexavalent chromium ［Cr（Ⅵ）］ contamination in solid-phase media，such as chromite ore processing residue （COPR） and chromium-contaminated soil from chromium chemical industries， a novel dispersedly stabilized iron-sulfur-based slurry （DSS-ISB） was developed. The slurry was modified with an inorganic dispersant to enhance the suspension stability and interfacial reactivity of iron-sulfur nanoparticles. The particle size of the slurry was approximately 200 nm， enabling efficient reduction and immobilization of Cr（Ⅵ） without pH adjustment. Optimization experiments achieved the optimal process parameters： a liquid-to-solid ratio of 5 mL∶10 g， and a DSS-ISB dosage of 1.8 mg/g. Under these conditions， the system achieved a Cr（Ⅵ） removal efficiency exceeding 97%， reducing the leaching concentration from 15.03 mg/L to 0.03 mg/L， which was below the China national standard limit of 5 mg/L （GB 5085.3—2007）. X-ray photoelectron spectroscopy （XPS） and Brunauer-Emmett-Teller （BET） analysis revealed that the remediation mechanism of DSS-ISB involves a combination of chemical reduction （with Fe2+/S2- as dual electron donors） and surface adsorption， effectively converting toxic Cr（Ⅵ） into stable Cr（Ⅲ）. Under the same remediation standard， compared with traditional reductants ferrous sulfate （FeSO4） and sodium sulfide （Na2S）， DSS-ISB increased the Cr（Ⅵ） removal efficiency by 28.24% and 6.23%， respectively， and increased the unit mass removal capacity by 92.43% and 77.08%， respectively. Meanwhile， the reagent cost per ton of COPR treated was reduced to RMB 36.40 yuan， achieving cost reductions of 33.82% and 26.02%，compared with FeSO4 （RMB 55.00 yuan） and Na2S （RMB 49.20 yuan）， respectively. In addition， the remediation process was simplified by eliminating the need for pH adjustment and subsequent passivation treatment. The DSS-ISB system is highly applicable to both COPR and in-situ chromium-contaminated soil， providing an economically efficient solution for the green remediation of Cr（Ⅵ） contamination.
To address the remediation of hexavalent chromium ［Cr（Ⅵ）］ contamination in solid-phase media，such as chromite ore processing residue （COPR） and chromium-contaminated soil from chromium chemical industries， a novel dispersedly stabilized iron-sulfur-based slurry （DSS-ISB） was developed. The slurry was modified with an inorganic dispersant to enhance the suspension stability and interfacial reactivity of iron-sulfur nanoparticles. The particle size of the slurry was approximately 200 nm， enabling efficient reduction and immobilization of Cr（Ⅵ） without pH adjustment. Optimization experiments achieved the optimal process parameters： a liquid-to-solid ratio of 5 mL∶10 g， and a DSS-ISB dosage of 1.8 mg/g. Under these conditions， the system achieved a Cr（Ⅵ） removal efficiency exceeding 97%， reducing the leaching concentration from 15.03 mg/L to 0.03 mg/L， which was below the China national standard limit of 5 mg/L （GB 5085.3—2007）. X-ray photoelectron spectroscopy （XPS） and Brunauer-Emmett-Teller （BET） analysis revealed that the remediation mechanism of DSS-ISB involves a combination of chemical reduction （with Fe2+/S2- as dual electron donors） and surface adsorption， effectively converting toxic Cr（Ⅵ） into stable Cr（Ⅲ）. Under the same remediation standard， compared with traditional reductants ferrous sulfate （FeSO4） and sodium sulfide （Na2S）， DSS-ISB increased the Cr（Ⅵ） removal efficiency by 28.24% and 6.23%， respectively， and increased the unit mass removal capacity by 92.43% and 77.08%， respectively. Meanwhile， the reagent cost per ton of COPR treated was reduced to RMB 36.40 yuan， achieving cost reductions of 33.82% and 26.02%，compared with FeSO4 （RMB 55.00 yuan） and Na2S （RMB 49.20 yuan）， respectively. In addition， the remediation process was simplified by eliminating the need for pH adjustment and subsequent passivation treatment. The DSS-ISB system is highly applicable to both COPR and in-situ chromium-contaminated soil， providing an economically efficient solution for the green remediation of Cr（Ⅵ） contamination.
2026,
44(6):
113-125.
doi: 10.13205/j.hjgc.202606012
Abstract:
River and lake sediments， as both the source and sink of water pollutants， have a significant impact on the water quality of overlying water bodies and aquatic ecosystems. In the processes of river and lake pollution treatment and ecological restoration， the treatment of polluted sediments is a vital component. Sediment remediation technologies can be divided into ex-situ remediation and in-situ remediation. In recent years， in-situ remediation has become a crucial research direction due to its advantages of low cost and minimal disturbance to the aquatic environment. This paper summarizes the pollution status of river and lake sediments， provides a comprehensive overview of the research progress， application status， and future requirements of physical， chemical， biological， and combined in-situ remediation technologies. It proposes optimization strategies for emerging technologies， advances in materials， and pathways for virtuous cycle development， while emphasizing the enhancement of research and application of remediation technologies through interdisciplinary integration.
River and lake sediments， as both the source and sink of water pollutants， have a significant impact on the water quality of overlying water bodies and aquatic ecosystems. In the processes of river and lake pollution treatment and ecological restoration， the treatment of polluted sediments is a vital component. Sediment remediation technologies can be divided into ex-situ remediation and in-situ remediation. In recent years， in-situ remediation has become a crucial research direction due to its advantages of low cost and minimal disturbance to the aquatic environment. This paper summarizes the pollution status of river and lake sediments， provides a comprehensive overview of the research progress， application status， and future requirements of physical， chemical， biological， and combined in-situ remediation technologies. It proposes optimization strategies for emerging technologies， advances in materials， and pathways for virtuous cycle development， while emphasizing the enhancement of research and application of remediation technologies through interdisciplinary integration.
2026,
44(6):
126-137.
doi: 10.13205/j.hjgc.202606013
Abstract:
The A2/O-MBR process， owing to its superior effluent quality and smaller footprint， is increasingly adopted in newly built and upgraded wastewater treatment plants. However， systematic studies on its greenhouse gas （GHG） emissions remain scarce， and direct comparisons with the conventional A2/O process are lacking. In this study， two full-scale wastewater treatment plants employing the A2/O and A2/O-MBR processes under identical influent conditions， climate， and discharge standards were investigated. A high-frequency monitoring system covering the entire treatment train was established， and combined with measurements of dissolved CH4 and N2O， water quality parameters， and operational parameters， to elucidate the differences in GHG emission characteristics. Results showed that the daily average CH4 emission intensities were not significantly different between the two plants ［（0.67 ± 0.22），（0.65 ± 0.18） g/m3， respectively］. CH4 emissions mainly originated from sewer-derived anaerobic production and subsequent release in the pretreatment units （accounting for over 70% of the total emissions）， with partial in-plant oxidation by methanotrophs. Temperature and aeration-induced stripping were identified as key driving factors， as CH4 emissions were positively correlated with ambient temperature and dissolved oxygen （DO）. In contrast， more than 90% of N2O emissions occurred in the biological treatment units. The A2/O-MBR plant exhibited significantly higher daily N2O emission intensity ［（0.132 ± 0.055） g/m3］ than the A2/O plant ［（0.060 ± 0.046） g/m3］， largely due to intensive aeration and oxygen-enriched internal/external recirculation in the membrane tank， which enhanced N2O production and stripping. Correlation analysis further revealed that N2O emissions in the A2/O plant were positively related to influent COD and BOD5， indicating dominance of heterotrophic denitrification， whereas in the A2/O-MBR process they were mainly driven by NH3-N loading and DO， reflecting a nitrification-based pathway. Importantly， both processes exhibited CH4 and N2O emission factors that were significantly lower than the reference values recommended by the IPCC and industry guidelines， underscoring the necessity of developing localized emission factors. This study fills a critical research gap concerning the greenhouse-gas generation and emission characteristics of the A2/O-MBR process， reveals the mechanistic differences between A2/O and A2/O-MBR process， and provides essential data to support greenhouse-gas emission inventories. The findings offer a scientific basis for targeted mitigation measures and can guide low-carbon process selection and planning for both upgrading existing urban wastewater treatment plants and designing new facilities.
The A2/O-MBR process， owing to its superior effluent quality and smaller footprint， is increasingly adopted in newly built and upgraded wastewater treatment plants. However， systematic studies on its greenhouse gas （GHG） emissions remain scarce， and direct comparisons with the conventional A2/O process are lacking. In this study， two full-scale wastewater treatment plants employing the A2/O and A2/O-MBR processes under identical influent conditions， climate， and discharge standards were investigated. A high-frequency monitoring system covering the entire treatment train was established， and combined with measurements of dissolved CH4 and N2O， water quality parameters， and operational parameters， to elucidate the differences in GHG emission characteristics. Results showed that the daily average CH4 emission intensities were not significantly different between the two plants ［（0.67 ± 0.22），（0.65 ± 0.18） g/m3， respectively］. CH4 emissions mainly originated from sewer-derived anaerobic production and subsequent release in the pretreatment units （accounting for over 70% of the total emissions）， with partial in-plant oxidation by methanotrophs. Temperature and aeration-induced stripping were identified as key driving factors， as CH4 emissions were positively correlated with ambient temperature and dissolved oxygen （DO）. In contrast， more than 90% of N2O emissions occurred in the biological treatment units. The A2/O-MBR plant exhibited significantly higher daily N2O emission intensity ［（0.132 ± 0.055） g/m3］ than the A2/O plant ［（0.060 ± 0.046） g/m3］， largely due to intensive aeration and oxygen-enriched internal/external recirculation in the membrane tank， which enhanced N2O production and stripping. Correlation analysis further revealed that N2O emissions in the A2/O plant were positively related to influent COD and BOD5， indicating dominance of heterotrophic denitrification， whereas in the A2/O-MBR process they were mainly driven by NH3-N loading and DO， reflecting a nitrification-based pathway. Importantly， both processes exhibited CH4 and N2O emission factors that were significantly lower than the reference values recommended by the IPCC and industry guidelines， underscoring the necessity of developing localized emission factors. This study fills a critical research gap concerning the greenhouse-gas generation and emission characteristics of the A2/O-MBR process， reveals the mechanistic differences between A2/O and A2/O-MBR process， and provides essential data to support greenhouse-gas emission inventories. The findings offer a scientific basis for targeted mitigation measures and can guide low-carbon process selection and planning for both upgrading existing urban wastewater treatment plants and designing new facilities.
2026,
44(6):
138-147.
doi: 10.13205/j.hjgc.202606014
Abstract:
As an emerging environmental pollutant， microplastics can adsorb psychotropic drugs in aquatic environments， followed by continuous migration and transformation， ultimately contributing to environmental pollution. To investigate the adsorption behavior and mechanism of microplastics for psychotropic drugs， four types of microplastics （PE， PP， PS， and PVC） with a particle size of 50 μm were selected as the experimental subjects， and three psychotropic drugs （diazepam， fluoxetine， and mianserin） were used to simulate the adsorption of these drugs by microplastics in water. The kinetic characteristics， adsorption isotherms， as well as the effects of pH and salinity on adsorption were examined. By fitting and analyzing the experimental data of the adsorption of psychotropic drugs by the four types of microplastics using the Langmuir and Freundlich isothermal adsorption models， it was found that PE adsorbed fluoxetine better， PP adsorbed mianserin better， and PVC adsorbed diazepam better， while a certain linear characteristic was observed in the adsorption of fluoxetine by PS. When the pH value of natural surface water ranged between 6.5 and 8.5， the adsorption of diazepam by microplastics reached a maximum. With an increase in NaCl concentration， the equilibrium adsorption capacity of diazepam in the solution also gradually increased. This is because the adsorption of diazepam is dominated by non-electrostatic interactions， and increasing the ionic strength can enhance the adsorption capacity of microplastics for diazepam in water.
As an emerging environmental pollutant， microplastics can adsorb psychotropic drugs in aquatic environments， followed by continuous migration and transformation， ultimately contributing to environmental pollution. To investigate the adsorption behavior and mechanism of microplastics for psychotropic drugs， four types of microplastics （PE， PP， PS， and PVC） with a particle size of 50 μm were selected as the experimental subjects， and three psychotropic drugs （diazepam， fluoxetine， and mianserin） were used to simulate the adsorption of these drugs by microplastics in water. The kinetic characteristics， adsorption isotherms， as well as the effects of pH and salinity on adsorption were examined. By fitting and analyzing the experimental data of the adsorption of psychotropic drugs by the four types of microplastics using the Langmuir and Freundlich isothermal adsorption models， it was found that PE adsorbed fluoxetine better， PP adsorbed mianserin better， and PVC adsorbed diazepam better， while a certain linear characteristic was observed in the adsorption of fluoxetine by PS. When the pH value of natural surface water ranged between 6.5 and 8.5， the adsorption of diazepam by microplastics reached a maximum. With an increase in NaCl concentration， the equilibrium adsorption capacity of diazepam in the solution also gradually increased. This is because the adsorption of diazepam is dominated by non-electrostatic interactions， and increasing the ionic strength can enhance the adsorption capacity of microplastics for diazepam in water.
2026,
44(6):
148-157.
doi: 10.13205/j.hjgc.202606015
Abstract:
This study investigated the performance and tissue-specific mechanisms of corn straw as a solid-phase carbon source for nitrate removal from groundwater. Through cyclic heterotrophic denitrification experiments， the denitrification efficiency， sustainability， DOC release characteristics， carbon utilization efficiency， intermediate accumulation， and environmental parameter variations were systematically evaluated across different tissues （leaf， stem pith， stem bark， stem node， husk， and mixed tissue）. Kinetic modeling， correlation analysis， and structural equation modeling were employed to elucidate the regulatory mechanisms of denitrification. The systems utilizing mixed tissues and bracts as carbon sources demonstrated the highest denitrification efficiency， exhibiting favorable slow-release characteristics and sustained carbon supply capacity. Across four repeated denitrification experiments， the nitrate removal rates were consistently maintained above 98%， while the concentrations of byproducts such as NO-2-N and NH+4-N remained at low levels. Correlation analysis and structural equation modeling revealed that carbon source type primarily influenced total nitrogen removal efficiency indirectly by regulating dissolved organic carbon （DOC） release， which subsequently affected system pH， electrical conductivity， and the transformation pathways of three nitrogen species （NO-3-N、NO-2-N and NH+4-N）. Significant differences were observed among corn stover tissue-based carbon sources in terms of denitrification efficiency， carbon utilization rate， nitrogen transformation pathways， and micro-environmental regulation. Among them， mixed tissues and bracts emerged as superior carbon sources due to their combined efficiency and stability. However， it is noteworthy that bracts tend to release odorous compounds during the reaction process， which may pose challenges in practical applications and necessitate further treatment.
This study investigated the performance and tissue-specific mechanisms of corn straw as a solid-phase carbon source for nitrate removal from groundwater. Through cyclic heterotrophic denitrification experiments， the denitrification efficiency， sustainability， DOC release characteristics， carbon utilization efficiency， intermediate accumulation， and environmental parameter variations were systematically evaluated across different tissues （leaf， stem pith， stem bark， stem node， husk， and mixed tissue）. Kinetic modeling， correlation analysis， and structural equation modeling were employed to elucidate the regulatory mechanisms of denitrification. The systems utilizing mixed tissues and bracts as carbon sources demonstrated the highest denitrification efficiency， exhibiting favorable slow-release characteristics and sustained carbon supply capacity. Across four repeated denitrification experiments， the nitrate removal rates were consistently maintained above 98%， while the concentrations of byproducts such as NO-2-N and NH+4-N remained at low levels. Correlation analysis and structural equation modeling revealed that carbon source type primarily influenced total nitrogen removal efficiency indirectly by regulating dissolved organic carbon （DOC） release， which subsequently affected system pH， electrical conductivity， and the transformation pathways of three nitrogen species （NO-3-N、NO-2-N and NH+4-N）. Significant differences were observed among corn stover tissue-based carbon sources in terms of denitrification efficiency， carbon utilization rate， nitrogen transformation pathways， and micro-environmental regulation. Among them， mixed tissues and bracts emerged as superior carbon sources due to their combined efficiency and stability. However， it is noteworthy that bracts tend to release odorous compounds during the reaction process， which may pose challenges in practical applications and necessitate further treatment.
2026,
44(6):
158-165.
doi: 10.13205/j.hjgc.202606016
Abstract:
To address the challenges of high sulfur content and difficult deep desulfurization of barium slag， this study employed sodium carbonate as the desulfurization agent. The effects of reaction temperature， reaction time， and sodium carbonate concentration on the desulfurization performance were systematically investigated. The phase transformation and microstructure evolution during the desulfurization process were characterized using XRD and SEM-EDS， and the corresponding reaction mechanism and limiting factors were clarified. The results indicated that the desulfurization of barium-containing waste slag primarily relied on the reaction between ettringite and sodium carbonate in solution， which formed calcium carbonate precipitates to remove sulfur. However， the precipitated calcium carbonate gradually accumulated on the surface of ettringite， hindering further progress of the desulfurization reaction. Under the optimal conditions of 60 °C， 5 h， and 2 mol/L Na2CO3， the desulfurization efficiency reached 91.21%， and the sulfur content of slag was reduced to 0.27%， meeting the standards for co-processing in cement kilns.
To address the challenges of high sulfur content and difficult deep desulfurization of barium slag， this study employed sodium carbonate as the desulfurization agent. The effects of reaction temperature， reaction time， and sodium carbonate concentration on the desulfurization performance were systematically investigated. The phase transformation and microstructure evolution during the desulfurization process were characterized using XRD and SEM-EDS， and the corresponding reaction mechanism and limiting factors were clarified. The results indicated that the desulfurization of barium-containing waste slag primarily relied on the reaction between ettringite and sodium carbonate in solution， which formed calcium carbonate precipitates to remove sulfur. However， the precipitated calcium carbonate gradually accumulated on the surface of ettringite， hindering further progress of the desulfurization reaction. Under the optimal conditions of 60 °C， 5 h， and 2 mol/L Na2CO3， the desulfurization efficiency reached 91.21%， and the sulfur content of slag was reduced to 0.27%， meeting the standards for co-processing in cement kilns.
2026,
44(6):
166-175.
doi: 10.13205/j.hjgc.202606017
Abstract:
Against the backdrop of deepening global green transition and tightening resource and environmental constraints， China advances Zero-Waste City construction under the Dual Carbon Goals， taking waste resource utilization as a critical pathway for sustainable development. As an essential basic metal for the national economy， zinc faces challenges such as high external dependence and an approaching primary resource exploitation threshold， making the regenerated zinc industry a core force to bridge the resource gap. However， Regenerated Zinc Raw Material（YS/T 1093—2015） has become outdated in its classification system， technical indicators， and environmental requirements， failing to adapt to industrial upgrading and the increasingly complex composition of raw materials. This paper focuses on YS/T 1093—2024， analyzing its revision background， core content， and impacts along the industrial chain. The revision renames the standard and clarifies its nature as front-end smelting intermediate feedstock. The new standard establishes a classification system covering six typical zinc-bearing materials （with expanded utilization of low-grade complex materials）， tightens limits on harmful elements （fluorine， chlorine， lead， etc.）， and adds practical indicators （moisture control， appearance evaluation）， enhancing operability and guidance. Compared with EU standards， it shows systematic improvements in raw material coverage， process adaptability and environmental risk control. Moreover， this paper discusses the standard’s implementation path and optimization directions from three dimensions： old-new comparison， practical industrial suggestions， and international alignment. Its implementation is expected to drive the regenerated zinc industry towards intensification， high-value utilization and clean production， improving resource recycling efficiency， reducing environmental pressure， and supporting China's zinc resource strategic security and low-carbon development.
Against the backdrop of deepening global green transition and tightening resource and environmental constraints， China advances Zero-Waste City construction under the Dual Carbon Goals， taking waste resource utilization as a critical pathway for sustainable development. As an essential basic metal for the national economy， zinc faces challenges such as high external dependence and an approaching primary resource exploitation threshold， making the regenerated zinc industry a core force to bridge the resource gap. However， Regenerated Zinc Raw Material（YS/T 1093—2015） has become outdated in its classification system， technical indicators， and environmental requirements， failing to adapt to industrial upgrading and the increasingly complex composition of raw materials. This paper focuses on YS/T 1093—2024， analyzing its revision background， core content， and impacts along the industrial chain. The revision renames the standard and clarifies its nature as front-end smelting intermediate feedstock. The new standard establishes a classification system covering six typical zinc-bearing materials （with expanded utilization of low-grade complex materials）， tightens limits on harmful elements （fluorine， chlorine， lead， etc.）， and adds practical indicators （moisture control， appearance evaluation）， enhancing operability and guidance. Compared with EU standards， it shows systematic improvements in raw material coverage， process adaptability and environmental risk control. Moreover， this paper discusses the standard’s implementation path and optimization directions from three dimensions： old-new comparison， practical industrial suggestions， and international alignment. Its implementation is expected to drive the regenerated zinc industry towards intensification， high-value utilization and clean production， improving resource recycling efficiency， reducing environmental pressure， and supporting China's zinc resource strategic security and low-carbon development.
2026,
44(6):
176-182.
doi: 10.13205/j.hjgc.202606018
Abstract:
Swine wastewater is a type of high-concentration organic wastewater， and hydrogen production during anaerobic fermentation is an important pathway for its conversion into clean energy. A comparative study on hydrogen production characteristics was conducted using three anaerobic sequencing batch reactors （ASBRs） for raw wastewater， the supernatant after MAP precipitation for nitrogen and phosphorus recovery， and the same supernatant co-treated with sludge heat-treated at 75°C for 0.5 hours. Without adjusting the influent pH， the hydrogen production rate in the raw wastewater reactor remained below 0.50 mmol/（kg·d）. When the influent COD concentration was 1800 mg/L， the hydrogen production rates in the MAP-pretreated reactor and co-treated reactor reached 48.17， 71.44 mmol/（kg·d）， respectively. At an influent COD concentration of 2400 mg/L， the methane concentrations in the raw， MAP-pretreated， and co-treated reactors were 10.8%， 14.2%， and 9.1%， respectively， indicating that MAP pretreatment significantly enhanced both hydrogen and methane production. Subsequently， as the influent load increased， the methane concentration in the raw wastewater reactor rose to 14.6%. Under these conditions， the average COD removal efficiencies for the raw， MAP-pretreated， and co-treated reactors were 78.9%， 70.8%， and 52.5%， respectively. Under pH-adjusted conditions， this study demonstrated that all three reactors achieved peak hydrogen production at pH 4.0， with production rates reaching 0.10， 7.74， and 8.83 mol/（kg·d）， respectively. This study provides valuable insights into exploring hydrogen production from swine wastewater through anaerobic processes.
Swine wastewater is a type of high-concentration organic wastewater， and hydrogen production during anaerobic fermentation is an important pathway for its conversion into clean energy. A comparative study on hydrogen production characteristics was conducted using three anaerobic sequencing batch reactors （ASBRs） for raw wastewater， the supernatant after MAP precipitation for nitrogen and phosphorus recovery， and the same supernatant co-treated with sludge heat-treated at 75°C for 0.5 hours. Without adjusting the influent pH， the hydrogen production rate in the raw wastewater reactor remained below 0.50 mmol/（kg·d）. When the influent COD concentration was 1800 mg/L， the hydrogen production rates in the MAP-pretreated reactor and co-treated reactor reached 48.17， 71.44 mmol/（kg·d）， respectively. At an influent COD concentration of 2400 mg/L， the methane concentrations in the raw， MAP-pretreated， and co-treated reactors were 10.8%， 14.2%， and 9.1%， respectively， indicating that MAP pretreatment significantly enhanced both hydrogen and methane production. Subsequently， as the influent load increased， the methane concentration in the raw wastewater reactor rose to 14.6%. Under these conditions， the average COD removal efficiencies for the raw， MAP-pretreated， and co-treated reactors were 78.9%， 70.8%， and 52.5%， respectively. Under pH-adjusted conditions， this study demonstrated that all three reactors achieved peak hydrogen production at pH 4.0， with production rates reaching 0.10， 7.74， and 8.83 mol/（kg·d）， respectively. This study provides valuable insights into exploring hydrogen production from swine wastewater through anaerobic processes.
2026,
44(6):
183-189.
doi: 10.13205/j.hjgc.202606019
Abstract:
The flue gas and dust generated by sludge co-combustion in coal-fired power plants exhibit high viscosity， leading to severe dust deposition on downstream environmental protection equipment. In this context， the dust deposition mechanism inside electrostatic precipitator （ESP） was analyzed， and the characteristics of dust layers were characterized. The results indicated that sludge co-combustion in coal-fired units increased flue gas moisture content， changed particle morphology， and elevated dust viscosity. To address this issue， an anode pneumatically rapped ESP technology was developed to improve the dust cleaning efficiency of the anode plates. This technology was applied to the retrofit of a 1000 MW coal-fired unit at Zhejiang Jiahua Power Plant， and corresponding engineering verification tests were carried out. ESP performance tests under sludge co-combustion conditions were completed in February 2025. The test results showed that， at a specific dust collection area of 118 m2·s/m3 and a unit load of 987 MW， the dust concentration at the outlet of the ESP decreased from 25.32 mg/m3 before the retrofit to 7.95 mg/m3 after the retrofit. Analysis revealed that sludge co-combustion caused excessive dust deposition on the anode plates of the first electric field， which induced back corona， high-voltage power supply flashover， and low operating parameters of secondary voltage and current. After the retrofit with the pneumatically rapped ESP， regions with low rapping acceleration on the plates were eliminated， achieving effective dust cleaning of anode plates. Meanwhile， the secondary voltage and current of the high-voltage power supply were significantly improved， and the overall dust collection efficiency of the ESP was remarkably enhanced. The proposed pneumatically rapped ESP technology can provide a reference for ESP retrofitting of coal-fired units under biomass （sludge） co-combustion and low-load operating conditions.
The flue gas and dust generated by sludge co-combustion in coal-fired power plants exhibit high viscosity， leading to severe dust deposition on downstream environmental protection equipment. In this context， the dust deposition mechanism inside electrostatic precipitator （ESP） was analyzed， and the characteristics of dust layers were characterized. The results indicated that sludge co-combustion in coal-fired units increased flue gas moisture content， changed particle morphology， and elevated dust viscosity. To address this issue， an anode pneumatically rapped ESP technology was developed to improve the dust cleaning efficiency of the anode plates. This technology was applied to the retrofit of a 1000 MW coal-fired unit at Zhejiang Jiahua Power Plant， and corresponding engineering verification tests were carried out. ESP performance tests under sludge co-combustion conditions were completed in February 2025. The test results showed that， at a specific dust collection area of 118 m2·s/m3 and a unit load of 987 MW， the dust concentration at the outlet of the ESP decreased from 25.32 mg/m3 before the retrofit to 7.95 mg/m3 after the retrofit. Analysis revealed that sludge co-combustion caused excessive dust deposition on the anode plates of the first electric field， which induced back corona， high-voltage power supply flashover， and low operating parameters of secondary voltage and current. After the retrofit with the pneumatically rapped ESP， regions with low rapping acceleration on the plates were eliminated， achieving effective dust cleaning of anode plates. Meanwhile， the secondary voltage and current of the high-voltage power supply were significantly improved， and the overall dust collection efficiency of the ESP was remarkably enhanced. The proposed pneumatically rapped ESP technology can provide a reference for ESP retrofitting of coal-fired units under biomass （sludge） co-combustion and low-load operating conditions.
2026,
44(6):
190-201.
doi: 10.13205/j.hjgc.202606020
Abstract:
In response to the widespread challenges faced by municipal wastewater treatment plants in China， such as influent grit loads exceeding design standards and insufficient carbon sources， as well as the limitations of conventional pretreatment processes （including screening， grit chambers， and primary sedimentation tanks）—namely， low removal efficiency of fine grit and poor retention of carbon sources—this study developed a novel pretreatment device known as the swinging ultra-fine screen. With a screening precision of 0.1 mm， the system was tested at a pilot scale of 1000 m3/d to systematically evaluate the pollutant removal efficiency of swinging ultra-fine screens with various aperture sizes ranging from 0.05 mm to 0.4 mm. The mechanisms were further investigated through particle size distribution analysis， COD fractionation， and characterization of the fouling layer. The results demonstrated that the swinging ultra-fine screen with a 0.1 mm aperture achieved an SS removal efficiency of 89.3%， significantly higher than the 57.4% obtained with conventional pretreatment processes. Meanwhile， the COD removal efficiency was only 9.5%， much lower than the 28.6% observed in traditional systems， indicating a carbon source retention efficiency as high as 93%. The device almost completely retained particles larger than 0.1 mm and achieved a removal efficiency exceeding 98% for particles in the 0.075 to 0.1 mm range. It also exhibited stable performance under fluctuating COD and SS conditions. Based on the experimental observations， a three-stage fouling theory for micro-screens was proposed. The 0.1 mm swinging ultra-fine screen represents a breakthrough by increasing the screening precision to 0.1 mm for the first time. It significantly enhances the removal efficiency of fine grit and effectively preserves bioavailable carbon sources， while demonstrating strong resilience to variations in water quality.
In response to the widespread challenges faced by municipal wastewater treatment plants in China， such as influent grit loads exceeding design standards and insufficient carbon sources， as well as the limitations of conventional pretreatment processes （including screening， grit chambers， and primary sedimentation tanks）—namely， low removal efficiency of fine grit and poor retention of carbon sources—this study developed a novel pretreatment device known as the swinging ultra-fine screen. With a screening precision of 0.1 mm， the system was tested at a pilot scale of 1000 m3/d to systematically evaluate the pollutant removal efficiency of swinging ultra-fine screens with various aperture sizes ranging from 0.05 mm to 0.4 mm. The mechanisms were further investigated through particle size distribution analysis， COD fractionation， and characterization of the fouling layer. The results demonstrated that the swinging ultra-fine screen with a 0.1 mm aperture achieved an SS removal efficiency of 89.3%， significantly higher than the 57.4% obtained with conventional pretreatment processes. Meanwhile， the COD removal efficiency was only 9.5%， much lower than the 28.6% observed in traditional systems， indicating a carbon source retention efficiency as high as 93%. The device almost completely retained particles larger than 0.1 mm and achieved a removal efficiency exceeding 98% for particles in the 0.075 to 0.1 mm range. It also exhibited stable performance under fluctuating COD and SS conditions. Based on the experimental observations， a three-stage fouling theory for micro-screens was proposed. The 0.1 mm swinging ultra-fine screen represents a breakthrough by increasing the screening precision to 0.1 mm for the first time. It significantly enhances the removal efficiency of fine grit and effectively preserves bioavailable carbon sources， while demonstrating strong resilience to variations in water quality.
2026,
44(6):
202-208.
doi: 10.13205/j.hjgc.202606021
Abstract:
In order to provide a theoretical basis for the energy-saving combustion of regenerative thermal oxidizers （RTOs）， it is necessary to analyze the energy nodes during RTO operation， refine the heat balance accounting， and establish an overall energy system for RTOs. Taking a three-chamber RTO as the research object and the entire RTO device as the analytical system， this study calculated the enthalpy of exhaust gas as it entered the RTO furnace at different stages. A whole-process heat balance model was established to systematically analyze the processes of exhaust gas preheating， combustion， heat recovery， and heat loss transfer. To address the dynamic heat exchange inside heat accumulators， the coupling of multiple gas streams， and boundary heat loss under complex working conditions， an improved energy accounting method was proposed. The longitudinal temperature distribution function of heat accumulators was introduced to address the difficulties in heat accounting inside the accumulator chamber. A thermodynamic system covering 11 key internal energy nodes of the RTO device was constructed. Combined with the design characteristics of RTO operation in different industries， this study analyzed the application scope of the overall energy system， which can be adjusted by modifying the equilibrium terms according to actual conditions， thus ensuring that the construction of the overall energy system has wide applicability. By constructing an RTO energy system for a glove manufacturing plant and conducting thermal balance calculations for verification， the prediction accuracy of outlet temperature can be improved from 14.3% to 2.8%， providing a theoretical basis for future research on intelligent energy-saving combustion.
In order to provide a theoretical basis for the energy-saving combustion of regenerative thermal oxidizers （RTOs）， it is necessary to analyze the energy nodes during RTO operation， refine the heat balance accounting， and establish an overall energy system for RTOs. Taking a three-chamber RTO as the research object and the entire RTO device as the analytical system， this study calculated the enthalpy of exhaust gas as it entered the RTO furnace at different stages. A whole-process heat balance model was established to systematically analyze the processes of exhaust gas preheating， combustion， heat recovery， and heat loss transfer. To address the dynamic heat exchange inside heat accumulators， the coupling of multiple gas streams， and boundary heat loss under complex working conditions， an improved energy accounting method was proposed. The longitudinal temperature distribution function of heat accumulators was introduced to address the difficulties in heat accounting inside the accumulator chamber. A thermodynamic system covering 11 key internal energy nodes of the RTO device was constructed. Combined with the design characteristics of RTO operation in different industries， this study analyzed the application scope of the overall energy system， which can be adjusted by modifying the equilibrium terms according to actual conditions， thus ensuring that the construction of the overall energy system has wide applicability. By constructing an RTO energy system for a glove manufacturing plant and conducting thermal balance calculations for verification， the prediction accuracy of outlet temperature can be improved from 14.3% to 2.8%， providing a theoretical basis for future research on intelligent energy-saving combustion.
2026,
44(6):
209-216.
doi: 10.13205/j.hjgc.202606022
Abstract:
Taking the volatile organic compounds （VOCs） catalytic combustion reactor of a certain enameled wire enterprise as the research object， Fluent software was used to conduct numerical simulation of its internal flow field. The effects of inlet expansion section length， inlet expansion section angle， and catalyst bed spacing on the velocity field within the reactor were investigated. Additionally， the changes in the reactor's temperature field following alterations to the heating tube configuration were analyzed. The results demonstrated that， considering the actual effective space and influencing factors such as the formation of flow recirculation zones， an expansion section length of 250 mm was deemed appropriate. The most homogeneous axial gas velocity distribution within the reactor was achieved when the expansion section angle was 0°； however， the expansion section angle should be selected according to specific operating conditions. A catalyst bed spacing of 0.05 m not only satisfied the engineering requirement of maintaining the pressure drop across a single catalyst layer at or below 200 Pa but also significantly improved gas flow distribution within the catalyst bed. The gas temperature distribution was found to be most favorable in the region with alternating heating tubes on both sides， as this configuration facilitated an overall temperature rise of the catalyst bed， thereby promoting the catalytic combustion process of VOCs.
Taking the volatile organic compounds （VOCs） catalytic combustion reactor of a certain enameled wire enterprise as the research object， Fluent software was used to conduct numerical simulation of its internal flow field. The effects of inlet expansion section length， inlet expansion section angle， and catalyst bed spacing on the velocity field within the reactor were investigated. Additionally， the changes in the reactor's temperature field following alterations to the heating tube configuration were analyzed. The results demonstrated that， considering the actual effective space and influencing factors such as the formation of flow recirculation zones， an expansion section length of 250 mm was deemed appropriate. The most homogeneous axial gas velocity distribution within the reactor was achieved when the expansion section angle was 0°； however， the expansion section angle should be selected according to specific operating conditions. A catalyst bed spacing of 0.05 m not only satisfied the engineering requirement of maintaining the pressure drop across a single catalyst layer at or below 200 Pa but also significantly improved gas flow distribution within the catalyst bed. The gas temperature distribution was found to be most favorable in the region with alternating heating tubes on both sides， as this configuration facilitated an overall temperature rise of the catalyst bed， thereby promoting the catalytic combustion process of VOCs.
