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Showing 32 of 146 peer-reviewed papers with full Graphical Abstracts.

Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512031• Jan 15, 2026

Adsorption Performance and Mechanism of Iron-Modified Sugarcane Bagasse Biochar for Amoxicillin in Aqueous Solution

Authors: LU Juncai, LIU Shuang, QU Jia, YOU Shaohong, JIANG Pingping, JU

The overuse of antibiotics has led to residual amoxicillin (AMX) in aquatic environments, promoting the spread of antibiotic resistance genes (ARGs) and threatening ecological safety. In this study, magnetic iron-modified biochar (Fe-BC) was prepared from agricultural waste sugarcane bagasse via FeCl3·6H2O impregnation and oxygen-limited pyrolysis. The adsorption performance and mechanism of Fe-BC for AMX were systematically investigated. Under conditions of 25 °C, pH 6, and initial AMX concentration of 50 mg·L−1, the adsorption capacity reached 32.61 mg·g−1. Characterization of Fe-BC before and after adsorption, combined with adsorption kinetics, isotherms, and thermodynamic analyses, revealed that adsorption primarily relied on oxygen-containing functional groups. The mechanisms included pore filling, electrostatic interaction, hydrogen bonding, complexation, and π–π interaction. After six thermal regeneration cycles, the removal efficiency of AMX remained above 76%. The specific surface area of Fe-BC increased from 279.20 m2·g−1 to 481.42 m2·g−1, an enhancement of approximately 72.4%. These results provide a technical reference for the resource utilization of agricultural waste and cost-effective treatment of antibiotic-containing wastewater in rural decentralized areas.

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Adsorption Performance and Mechanism of Iron-Modified Sugarcane Bagasse Biochar for Amoxicillin in Aqueous Solution

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202508006• Jan 15, 2026

Enhanced Nitrogen Removal from Landfill Leachate via a Two-Stage A/O–MBBR System Coupled with Anammox

Authors: LIU Jianxi, LIU Hongtao, TAN Yong, GUO Juncheng, LIU Sichen, TAN Cong

Landfill leachate, characterized by high ammonia nitrogen, high organic load, complex toxic components, and low nitrogen removal efficiency, poses significant environmental challenges. To achieve efficient nitrogen removal, a continuous-flow two-stage anoxic/oxic (A/O) moving-bed biofilm reactor (MBBR) system coupled with anaerobic ammonium oxidation (Anammox) was constructed and operated for long-term treatment of actual landfill leachate. After biofilm attachment and multi-gradient acclimation, influent concentrations were gradually increased from low levels (NH4+-N ~200 mg·L−1, COD ~2500–3000 mg·L−1) to high levels (NH4+-N ~1800 mg·L−1, COD ~8500 mg·L−1). During stable operation, average removal efficiencies of NH4+-N and COD reached 97.7% and 66.8%, respectively, with total nitrogen (TN) removal efficiency improving to 93.9%. Along the reactor, the first A/O stage achieved major organic degradation and ammonia oxidation, while the second stage facilitated nitrite accumulation and promoted Anammox for synergistic nitrogen removal. High-throughput sequencing revealed Proteobacteria as the dominant phylum (>50%), with denitrifying genera such as Azoarcus and Thauera significantly enriched. Planctomycetota abundance increased from 0.6% to 3.7%, and Candidatus Kuenenia was detected, confirming successful Anammox colonization and participation in nitrogen removal. This study validates the efficient combined nitrogen removal mechanism of the A/O–MBBR system with Anammox, providing theoretical basis and technical support for engineering treatment of high-ammonia wastewater.

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Enhanced Nitrogen Removal from Landfill Leachate via a Two-Stage A/O–MBBR System Coupled with Anammox

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512064• Jan 15, 2026

Cerium-Based Magnetic Y-Type Molecular Sieve for Deep Removal of Fluoride Ions from Water

Authors: FANG Wanrong, QIU Zhaofu, WANG Yuan, LI Shangshu, JIN Xibiao

With increasingly stringent discharge standards for fluoride-containing wastewater, there is an urgent need for cost-effective, easily operable adsorbents capable of rapid adsorption and separation for deep defluorination. In this study, a novel adsorbent, Ce-FMSY, was successfully prepared by co-precipitation of cerium (Ce) and Fe3O4 onto Y-type molecular sieve (MSY). The effects of Ce/Fe mass ratio, adsorption time, initial solution pH, and coexisting anions on adsorption performance were systematically investigated. Results showed that at a Ce loading of 1.0% and Ce/Fe mass ratio of 2:1, Ce-FMSY rapidly adsorbed 86.2% of F− within 30 min, with a maximum adsorption capacity of 4.139 mg·g−1. The saturated magnetization of Ce-FMSY was 13.4 emu·g−1, enabling rapid solid-liquid separation. The adsorbent maintained a stable fluoride removal rate of 77.1%–96.8% over an initial pH range of 3–9. Adsorption kinetics and isotherm fitting indicated that F− adsorption onto Ce-FMSY followed pseudo-second-order kinetics and the Freundlich model, suggesting chemisorption as the dominant mechanism, involving rapid diffusion, surface complexation, and valence transformation reactions. After five adsorption-desorption cycles, the adsorption capacity slightly decreased and then stabilized, with F− removal efficiency maintained at approximately 72.3% of the initial value. This study provides data support and theoretical reference for deep fluoride removal from wastewater.

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Cerium-Based Magnetic Y-Type Molecular Sieve for Deep Removal of Fluoride Ions from Water

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202510044• Jan 15, 2026

Catalytic Conversion Behavior and Degradation Mechanisms of Sulfur-Containing Multi-Pollutants such as Thiols and Thioethers: A Review

Authors: FENG Yu, FANG Jian, XU Zhizhi, LAI Junyu, LU Jichang, LUO Yongming

The efficient treatment of sulfur-containing volatile organic compounds (S-VOCs) has become a critical task for air pollution control and green low-carbon transition under China's 14th Five-Year Plan. Industrial emissions often contain multiple S-VOC species, whose interactions can complicate degradation pathways, generate uncontrollable byproducts, and deactivate catalysts, limiting practical application. This review systematically summarizes the past decade of research on catalytic degradation of thiols and thioethers in multi-pollutant systems, focusing on competitive adsorption mechanisms, interfacial reaction pathways, and environmental factor regulation. Performance differences and reaction mechanisms across various catalyst systems under coexisting S-VOCs and inorganic sulfur are compared. Key findings indicate that mixed thiol systems exhibit faster deactivation than single-component systems due to temperature-dependent competitive adsorption and pathway switching, governed by molecular size–active site matching. Strategies such as metal–support strong interactions, zeolite confinement, nanocluster effects, and single-atom catalysts have improved activity and stability. However, dynamic competition mechanisms at active sites remain unresolved. Future research should develop atomic/molecular-level characterization techniques and multi-variable kinetic models, and shift from end-of-pipe purification to resource recovery, e.g., converting H2S and thiols into high-value chemicals like methanethiol, achieving dual goals of pollution control and sulfur resource recycling.

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Catalytic Conversion Behavior and Degradation Mechanisms of Sulfur-Containing Multi-Pollutants such as Thiols and Thioethers: A Review

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511043• Jan 15, 2026

Dominant Role of Digestate Biochar-Modified Zero-Valent Iron Interfacial Structure in Regulating Nitrobenzene Reduction Efficiency

Authors: LIU Daicheng, LI Yongqiang, CHEN Jingkang, XIONG Lei, GUO Dajiang, JU

Zero-valent iron (ZVI) suffers from surface passivation and low electron utilization in reductive removal of nitrobenzene (NB). To address these issues, a ball-milled iron/digestate biochar composite (BM-Fe/DBC) was prepared and compared with a physically mixed counterpart (PM-Fe/DBC). Characterization revealed that ball milling tightly embedded ZVI particles into the carbon matrix, forming Fe–C chemical bonds and a strong interfacial coupling structure that established efficient electron transfer channels. This structure significantly enhanced the micro-galvanic effect between iron and carbon, yielding superior reduction performance across a wide pH range (3–9). Under optimal conditions (Fe:C mass ratio 2:1, dosage 1.0 g·L−1, pH 5), BM-Fe/DBC achieved 79.9% NB removal, and the generation of aniline (AN) was 1.85 times that of PM-Fe/DBC. Mechanistic studies indicated that the intimate Fe–C interfacial coupling promoted sustained ZVI corrosion and enhanced the production of indirect reducing species, including adsorbed Fe(II) and atomic hydrogen (H*). Electrochemical analyses showed that BM-Fe/DBC exhibited a lower corrosion potential, a higher corrosion current density (approximately 2.15 times higher), and lower charge transfer resistance, kinetically confirming its superior electron transfer capability. These findings reveal that constructing strong interfacial coupling in iron–carbon composites via mechanochemical methods can effectively overcome key limitations of ZVI in reduction reactions, providing a theoretical basis and practical pathway for designing high-performance water treatment materials.

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Dominant Role of Digestate Biochar-Modified Zero-Valent Iron Interfacial Structure in Regulating Nitrobenzene Reduction Efficiency

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202510042• Jan 15, 2026

Empowering a Chinese-Characteristic Waste Classification Model with Mid-End Intelligent Sorting

Authors: JIANG Zixuan, WEN Zongguo, HU Yupeng, WU Jianyang, WU Jiancheng, ZHANG Liping

Given China's escalating municipal solid waste (MSW) generation and the limitations of current classification schemes, this study proposes a novel waste classification model centered on mid-end intelligent sorting technology. The approach integrates targeted pretreatment with multimodal visual recognition and robotic grasping to efficiently sort complex household waste, while compact equipment innovations adapt to the low-value characteristics of recyclables. An engineering demonstration case shows that the technology can effectively recover low-value recyclables comprising 15%–30% of mixed MSW. If applied at 5% of a case city's waste transfer stations, approximately 5×10^4 t of recyclables could be sorted annually. Preliminary estimates indicate a 20% return on investment for operators at an 80 t·d−1 scale. The study demonstrates that mid-end intelligent sorting offers a technically feasible and economically sustainable solution to reduce fiscal expenditure on waste classification while improving efficiency.

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Empowering a Chinese-Characteristic Waste Classification Model with Mid-End Intelligent Sorting

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512045• Jan 15, 2026

Electrocatalytic Degradation of Phenol by Sn-Sb Co-doped Ti/SnO2 Electrode: Performance and Mechanism

Authors: XIE Haoyu, WANG Tianyu, LI Yanhong, LIU Ruiping

To optimize the anode structure of Ti/SnO2-based electrodes in electrochemical advanced oxidation processes (EAOPs) and enhance their electrocatalytic activity and stability, Sn-Sb co-doped Ti/SnO2 electrodes were fabricated via a sol-gel method. The degradation performance and mechanism were evaluated using phenol as a model pollutant. Three electrodes were prepared with different Sn/Sb molar ratios: Ti/SnO2 (10:0), Ti/Sb (0:10), and Ti/SnO2-Sb (9:1). Characterization by XRD, SEM, and electrochemical tests revealed that the Sn-Sb co-doped electrode exhibited a dense surface, higher oxygen evolution potential (OEP), larger electrochemically active surface area, and lower charge transfer resistance compared to single-doped counterparts. In constant-current electrolysis experiments (20 mA·cm−2, pH=5, 0.1 mol·L−1 Na2SO4), the co-doped electrode achieved superior phenol and TOC removal efficiencies and higher apparent rate constants, with the lowest specific energy consumption per unit TOC removal. Radical quenching and intermediate analysis indicated that hydroxyl radicals (·OH) were the dominant reactive species. The degradation pathway involved aromatic ring hydroxylation, ring opening, and further mineralization of short-chain carboxylic acids. Sn-Sb co-doping enhanced the generation of ·OH by increasing surface adsorbed oxygen and defect site density. This synergistic doping strategy significantly improved the electrocatalytic activity and service life of Ti/SnO2-based anodes, providing a basis for the rational design of anode materials for EAOPs in treating refractory organic wastewater.

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Electrocatalytic Degradation of Phenol by Sn-Sb Co-doped Ti/SnO2 Electrode: Performance and Mechanism

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511095• Jan 15, 2026

Characteristics of Autumn–Winter Daily Atmospheric Dustfall Pollution in the Core Area of Beijing

Authors: HUANG Yu-hu, LIU Li-yang, LI Bei-bei, WANG Yu, LIANG Jing, ZHAO Yu, QIN Jian-ping

To address the low temporal resolution of conventional monthly dustfall monitoring and the lack of component information, this study proposed a daily dustfall measurement method that adds a filtration step to the Chinese standard method, referencing international standards. Using a sand-core filtration device with quartz or mixed cellulose ester membranes, the method achieved a spiked recovery of 101.1% ± 1.2%, good parallelism (y = 0.95x + 0.28), and satisfactory temporal closure. During autumn–winter (November 2020 to March 2021) at a representative site in Xicheng District, Beijing, daily dustfall ranged from 0.06 to 2.33 t·(km²·d)−1. Days with daily dustfall exceeding 0.7 t·(km²·d)−1 accounted for only 4% of the sampling days but contributed 25% of the total dustfall, with high values mainly occurring in January, March, and December. The insoluble fraction averaged 83% ± 12%, and a logarithmic model (y = 9.36ln(x) + 99.98) was established to estimate the insoluble proportion from insoluble dustfall (x, ≤1.00). Daily dustfall showed a strong positive correlation with average wind speed, and an exponential prediction model (y = 0.06e0.61x) was derived. Windy conditions (≥3 on the Beaufort scale) significantly amplified dustfall. The study recommends suspending earthwork, covering bare ground, and increasing watering frequency during high-wind alerts to mitigate dust pollution. This work provides a reliable method for high-resolution dustfall monitoring and insights for targeted pollution control in urban core areas.

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Characteristics of Autumn–Winter Daily Atmospheric Dustfall Pollution in the Core Area of Beijing

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511055• Jan 15, 2026

Numerical Simulation of Water Environment in the Mountainous River of the Upper Heihe River Based on MIKE21

Authors: WANG Yu, WEI Xiaozhen, LUO Tianfeng, WANG Hao, TIAN Miao, SUN Chao, ZHANG Xiaolong, REN Weilong, HU Feiyan

To systematically investigate the spatiotemporal distribution of hydrodynamics and water quality under cascaded hydropower development in the upper Heihe River, a MIKE21-based water environment model was constructed for the mountainous reach. The model simulated the dynamic changes of total phosphorus (TP), total nitrogen (TN), and ammonia nitrogen (NH3-N) from January to August 2023. Calibration and validation against field data showed good performance: the hydrodynamic model achieved a coefficient of determination (R2) of 0.89 and a mean relative error (MRE) of 11.3%; the water quality model achieved an average R2 of 0.86 and an average MRE of 14.21%. Hydrodynamic simulations revealed average flow velocities of 1.78, 0.72, and 0.36 m·s−1 during wet, normal, and dry periods, respectively. Natural river sections exhibited high velocities up to 4.3 m·s−1, while reservoir sections had near-stagnant flow due to hydraulic structures. Water quality simulations indicated that TN and NH3-N concentrations were higher in dry and normal periods, whereas TP was higher in the wet period. Spatially, concentrations in reservoir sections exceeded those in natural sections: natural sections had TP, TN, and NH3-N concentrations of 0.07–0.10, 0.25–0.50, and 0.025–0.250 mg·L−1, respectively, while reservoir sections had 0.12–0.17, 0.60–0.80, and 0.10–0.45 mg·L−1. These findings provide scientific references for water environment management in the Heihe River and similar inland river basins.

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Numerical Simulation of Water Environment in the Mountainous River of the Upper Heihe River Based on MIKE21

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512057• Jan 15, 2026

Preparation of Slag-Based Carbon Powder-Sodium Alginate Composite Membrane and Its Efficient Adsorption of Cr(VI) from Aqueous Solutions

Authors: CHEN Qiuyi, ZHANG Zhe, HUO Qiang, MO Yuanyuan, JU

A novel slag-based carbon powder-sodium alginate composite membrane was fabricated by incorporating purified slag-derived carbon powder into a sodium alginate matrix, followed by dual crosslinking with polyethyleneimine and glutaraldehyde. The membrane was designed to achieve waste-to-treat-waste objectives, enhance the resource value of industrial slag, and provide an efficient, regenerable adsorbent for Cr(VI) removal from water. Adsorption performance was systematically evaluated. Optimal adsorption occurred at pH 2, with elevated temperature and initial Cr(VI) concentration favoring uptake; equilibrium was reached at approximately 73 h. The adsorption kinetics followed a pseudo-second-order model, and isotherm data fitted the Langmuir model, yielding a theoretical maximum adsorption capacity of 471.970 mg·g−1. Thermodynamic analysis indicated a spontaneous, endothermic process. In simulated wastewater containing multiple metal ions, competitive effects moderately reduced adsorption capacity. After three adsorption-desorption cycles, the membrane retained good structural stability despite a decline in capacity. Characterization via SEM-EDS, FTIR, and XPS revealed a porous structure and the involvement of functional groups such as –COOH and –NH2, with partial reduction of Cr(VI) to Cr(III). The adsorption mechanism was attributed to synergistic electrostatic interaction, chemical coordination, and redox reactions.

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Preparation of Slag-Based Carbon Powder-Sodium Alginate Composite Membrane and Its Efficient Adsorption of Cr(VI) from Aqueous Solutions

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202504023• Jan 15, 2026

Interpretation of the National Standard GB/T 19515—2023: Requirements and Calculation Methods for Recyclability Rate and Recoverability Rate of Road Vehicles

Authors: ZHANG Tongzhu, HOU Meng

The national standard GB/T 19515—2023, titled "Road vehicles - Recyclability and recoverability - Requirements and calculation methods," has been officially released and implemented. This standard is crucial for guiding automotive manufacturers in selecting recyclable materials for new products and enhancing the potential recyclability and recoverability of vehicles. This paper provides a comprehensive interpretation of the standard, covering its background, significance, technical requirements for the two rates (recyclability rate and recoverability rate), and the calculation methods. The standard aims to assist automotive enterprises in establishing a calculation system for these rates, thereby improving the recyclability performance of vehicles, reducing waste from end-of-life vehicles, and promoting the circular economy within the automotive industry. Key aspects include the alignment with international standards such as ISO 22628 and EU directives, the historical evolution of the standard from 2004 to 2023, and the detailed calculation methodology based on four stages of end-of-life vehicle processing: pre-treatment, dismantling, metal separation, and treatment of non-metallic residues. The paper also highlights the importance of design-phase considerations and the need for manufacturers to collect accurate material data from their supply chains. Future improvements to the standard are discussed, including expanding vehicle type coverage and refining material identification requirements.

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Interpretation of the National Standard GB/T 19515—2023: Requirements and Calculation Methods for Recyclability Rate and Recoverability Rate of Road Vehicles

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512059• Jan 15, 2026

Construction of Thiol-Functionalized Chitin and Its Adsorption Performance and Mechanism for Pd(II)

Authors: LUO Yi, YAN Linzhe, LI Bo, XUE Zhenluan, SHAO Penghui

Recovery of palladium from Pd-bearing wastewater is economically and environmentally significant. Adsorption is a promising method due to its simplicity, low cost, and high efficiency. In this study, a novel thiol-modified adsorbent (CHT-SH) was synthesized via one-step functionalization of inexpensive chitin (CHT) with thioglycolic acid. At room temperature and pH=2, CHT-SH exhibited an experimental adsorption capacity of 223.67 mg·g−1 for Pd(II), which was approximately 7 times higher than that of pristine CHT (30.6 mg·g−1). Kinetic and isotherm studies indicated that the adsorption process followed the pseudo-second-order kinetic model and the Langmuir isotherm model, with a maximum theoretical adsorption capacity of 248.89 mg·g−1, suggesting monolayer chemisorption. Characterization (FTIR, SEM, XPS, XRD) and density functional theory (DFT) calculations revealed that the adsorption mechanism primarily involved synergistic coordination of nitrogen and sulfur atoms, along with electrostatic interactions. Furthermore, CHT-SH demonstrated good reusability, retaining stable adsorption capacity after five adsorption-desorption cycles. Compared to other adsorbents that rely on redox mechanisms and are costly, CHT-SH offers comprehensive advantages. This work provides a cost-effective and efficient adsorbent for Pd(II) recovery from wastewater, offering technical support and theoretical reference for practical applications.

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Construction of Thiol-Functionalized Chitin and Its Adsorption Performance and Mechanism for Pd(II)

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512052• Jan 15, 2026

Performance of Iron-Carbon-Manganese Ore Composite Substrate Constructed Wetland for Simultaneous Removal of Nitrogen and Tetracycline

Authors: CHENG Yuwei, LU Xixin, ZHANG Haiqing, HAO Yinli, QU Dan, LIU Yongze, JIN Rencai, HUANG Jinkun, ZHU Yan

Constructed wetlands (CWs) with conventional substrates often exhibit limited removal of nitrogen and antibiotics from secondary effluent. This study developed an iron-carbon-manganese ore (Fe-C-Mn) composite substrate CW to enhance simultaneous removal of nitrogen and tetracycline (TC). Under influent TC of 2 mg·L−1 and total nitrogen (TN) of 15 mg·L−1, the Fe-C-Mn system achieved average TC removal of 91.3%, significantly higher than the gravel control (27.2%). TN and nitrate nitrogen (NO3−-N) removals reached 71.7% and 83.3%, respectively, versus 7.8% and 1.2% in the control. Substrate analysis revealed increased surface roughness and synergistic generation of active components (Fe(II)/Fe(III) and Mn(II)), driving autotrophic denitrification and TC biodegradation/chemical degradation. Microbial community analysis indicated reduced overall diversity but selective enrichment of potential TC degraders (e.g., Trichosporon, Bacillota) and denitrifiers (e.g., unclassified_f_Rhodocyclaceae). TC degradation pathways included demethylation, hydroxylation, and ring-opening, ultimately yielding small metabolites. These findings provide theoretical and technical support for enhanced removal of antibiotics and nitrogen from secondary effluent using CWs.

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Performance of Iron-Carbon-Manganese Ore Composite Substrate Constructed Wetland for Simultaneous Removal of Nitrogen and Tetracycline

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512025• Jan 15, 2026

Stratification of Persulfate in Porous Aquifers and Its Impact on Remediation of Light Non-Aqueous Phase Liquid Contamination

Authors: YANG Wei, CHEN Yudao, JU, LI Weixuan, TANG Dongbo, DU Liu, YAN Xue

Persulfate (PS) is a common oxidant in in-situ chemical oxidation (ISCO) for groundwater organic contamination, but its vertical concentration stratification may lead to inefficient remediation of light non-aqueous phase liquids (LNAPLs). To investigate the vertical stratification characteristics of PS in porous aquifers and its impact on LNAPLs remediation, static water column experiments and flowing water sand tank experiments were conducted. The migration behavior of PS under non-slow-release and slow-release conditions was compared, with Br− as a reference tracer and benzene, toluene, and xylene (BTX) as LNAPLs contaminants. Results showed that in static water columns, Br− exhibited weak vertical migration, short migration distance, and a low decay rate (0.009 d−1), consistent with a stable tracer. In contrast, PS showed strong vertical migration, with concentrations increasing with depth; under slow-release conditions, the concentration difference between the top and bottom of the column could reach two orders of magnitude. Br− migration was dominated by molecular diffusion (effective diffusion coefficient 2.2×10−9 m2·s−1), while PS migration was driven by both diffusion and density. Under slow-release conditions, the average PS decay rate was 0.072 d−1, slightly higher than the non-slow-release rate (0.059 d−1). In both column and sand tank experiments, BTX exhibited a distinct shallow-layer distribution, contrasting with PS. When the aquifer thickness is large, PS stratification limits its contact with LNAPLs contaminants, increasing remediation cost and difficulty. These findings provide theoretical reference for PS-based ISCO remediation of LNAPLs in porous aquifers.

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Stratification of Persulfate in Porous Aquifers and Its Impact on Remediation of Light Non-Aqueous Phase Liquid Contamination

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511005• Jan 15, 2026

Nitrogen Removal Performance of Tidal Flow Constructed Wetlands Based on α-Fe2O3/Volcanic Rock Mixed Substrate

Authors: GONG Jiaxing, GUO Jie, LUO Xiao, ZHANG Rui

To enhance the adsorption performance of volcanic rock for nitrogen in water, an α-Fe2O3/volcanic rock composite was successfully prepared via ferric citrate impregnation and calcination. Its adsorption characteristics for NH4+-N and NO3−-N and application in tidal flow constructed wetlands (TFCWs) were systematically investigated. Results showed that the adsorption kinetics of both nitrogen forms followed a pseudo-second-order model, indicating chemisorption dominance. Langmuir and Freundlich isotherm models both fitted the data, suggesting coexistence of monolayer and multilayer adsorption. The saturated adsorption capacities of α-Fe2O3/volcanic rock for NH4+-N and NO3−-N were 0.055 mg·g−1 and 0.067 mg·g−1, respectively. In TFCWs using this composite as substrate, average removal efficiencies for NH4+-N and NO3−-N reached 72.51% and 68.13%, respectively. Furthermore, microbial community abundance and diversity in the wetland system significantly increased, indicating that α-Fe2O3 introduction effectively enhanced microbial activity, thereby improving nitrogen removal efficiency.

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Nitrogen Removal Performance of Tidal Flow Constructed Wetlands Based on α-Fe2O3/Volcanic Rock Mixed Substrate

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512015• Jan 15, 2026

Stabilization Efficiency and Mechanisms of Iron-Manganese Phosphate Modified Biochar for Cadmium, Lead, and Zinc Co-Contaminated Soil

Authors: LI Jiayue, ZHU Bin, ZUO Jianfen, YAN Ximing, LIU Yang, PAN Bo, HUANG Jianhong, JU

The co-contamination of cadmium (Cd), lead (Pb), and zinc (Zn) in agricultural soils near mining areas poses significant risks to ecosystems and human health. Conventional stabilization materials often exhibit insufficient performance for Zn, particularly in multi-metal systems. This study synthesized a novel composite biochar (PFMBC) by loading phosphate and iron-manganese oxides onto biochar via phosphoric acid impregnation followed by secondary pyrolysis at 600 °C. The stabilization efficiency of PFMBC was evaluated against pristine biochar (BC) and iron-manganese modified biochar (FMBC) in a soil collected from a lead-zinc mining area (total Cd: 43.77 mg·kg−1, Pb: 3355.94 mg·kg−1, Zn: 1296.57 mg·kg−1). After 60 days of incubation with 5% PFMBC, the DTPA-extractable (bioavailable) fractions of Cd, Pb, and Zn decreased by 73.44%, 90.10%, and 69.33%, respectively, significantly outperforming BC and FMBC. Sequential extraction indicated that PFMBC promoted the transformation of Cd, Pb, and Zn from acid-soluble and reducible fractions to more stable residual fractions. Characterization via FTIR, SEM, and XRD revealed enhanced surface functional groups and the formation of stable mineral phases. The synergistic effects of phosphate precipitation, iron-manganese oxide adsorption, and surface complexation contributed to the superior stabilization, particularly overcoming the challenge of Zn immobilization. These findings demonstrate that PFMBC is a promising amendment for the remediation of Cd-Pb-Zn co-contaminated soils, offering high efficiency and long-term stability.

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Stabilization Efficiency and Mechanisms of Iron-Manganese Phosphate Modified Biochar for Cadmium, Lead, and Zinc Co-Contaminated Soil

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511027• Jan 15, 2026

Nutrient Release Characteristics of Aquaculture Sludge through Anaerobic Acidification in an Aquaponics System

Authors: ZI Yongxia, HE Xinmeng, GAO Yueshu, LI Chunjie

Aquaponics systems integrate aquaculture and hydroponics to recycle resources, yet nutrient recovery from aquaculture sludge remains inefficient. This study investigated anaerobic acidification as an alternative to conventional anaerobic digestion, which suffers from long conversion cycles. Batch experiments compared two sludge loading rates: high (13.22 kg·kg−1) and low (4.61 kg·kg−1) (mass of sludge per mass of anaerobic inoculum). Under low loading, soluble chemical oxygen demand (SCOD) exhibited a single peak, reaching a maximum organic solid conversion of 68.2% at 70.5 h. In contrast, high loading produced three SCOD peaks with an average peak conversion efficiency of only 26.9% at 27.5 h and higher residual concentrations. Ammonia nitrogen conversion was slightly higher under low loading (64.8%) than high loading (62.2%), while orthophosphate conversion was markedly superior (95.7% vs. 76.4%). The optimal hydraulic retention time for low-loading operation was 144 h, corresponding to an organic loading rate of 0.77 kg·(kg·d)−1. Under these conditions, the produced ammonia and phosphate can be effectively recovered without adversely affecting water quality, as the biofilter converts ammonia to nitrate for plant uptake. Microbial analysis revealed that low-loading conditions favored the dominance of Acinetobacter (relative abundance 66.6%), which likely enhances organic degradation and nutrient release. These findings demonstrate that anaerobic acidification under low loading is a promising strategy for efficient nutrient recovery in aquaponics, offering a shorter conversion time and higher nutrient yields than traditional methods.

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Nutrient Release Characteristics of Aquaculture Sludge through Anaerobic Acidification in an Aquaponics System

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202510071• Jan 15, 2026

Removal of Nitrate from Livestock Wastewater Using Composite Carbon Sources of Corncob and Polycaprolactone

Authors: TANG Qiang, YAN Xiaoping, HE Xiao, LIU Siqi, ZHAO Shengwei, JIANG Rong, YANG Zhanbiao

Carbon source is a critical factor driving heterotrophic denitrification, yet the low carbon-to-nitrogen ratio (C/N) of livestock wastewater limits this process. This study developed novel composite carbon sources by combining corncob (CC) and polycaprolactone (PCL). Static carbon release and denitrification experiments were conducted to evaluate carbon release patterns and nitrogen removal performance. Results showed that the carbon release index (n) was below 0.45, indicating Fickian diffusion as the dominant release mechanism. The composite carbon source prepared at a CC:PCL mass ratio of 3:2 (denoted YP4) achieved a nitrate nitrogen removal efficiency of 94.76%, with effluent ammonia nitrogen meeting the discharge limits of GB 18596-2001. High-throughput sequencing revealed that YP4 increased the relative abundance of genera capable of denitrification and biopolymer degradation (e.g., Aeromonas, Novosphingobium, Bacteroides, and Clostridium sensu stricto), thereby enhancing heterotrophic denitrification and nitrogen removal. These findings provide a novel approach for selecting and preparing external carbon sources for biological heterotrophic denitrification of low C/N wastewater.

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Removal of Nitrate from Livestock Wastewater Using Composite Carbon Sources of Corncob and Polycaprolactone

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512014• Jan 15, 2026

Application of Microporous Bio-Gravel for Microecological Remediation of Degraded Mine Soils

Authors: WANG Jingwen, HU Hao, LIU Yongjie, LI Jingguo, QU Laiye, ZHANG Naili, TAO Siqi

Mining activities cause severe soil degradation and microbial diversity loss, impeding ecological restoration. This study evaluated the effects of a novel soil amendment, microporous bio-gravel (MBG), on bacterial and fungal community structure and function in degraded soil from the Baiyinhua open-pit mine, Inner Mongolia. A pot experiment with four MBG-to-soil volume ratios (CK, L=1:3, M=1:2, H=1:1) was conducted, with a simplified plant community and uniform fertilization. After 180 days, soil samples were analyzed via high-throughput sequencing and bioinformatics. Results showed that the medium ratio (M) significantly increased fungal Shannon index and evenness, while the high ratio (H) negatively affected bacterial communities. At phylum and genus levels, MBG promoted enrichment of Cyanobacteria and specific functional groups (e.g., nitrogen-fixing bacteria, Bacillus). Co-occurrence network analysis revealed peak complexity, modularity, and average degree in bacterial and fungal networks under the M treatment. Functional prediction indicated significant enrichment of pathways related to lipopolysaccharide biosynthesis, nitrotoluene degradation, and plant-pathogen interactions, alongside increased abundance of saprotrophic and ectomycorrhizal fungi. Mantel and VPA analyses showed that MBG indirectly regulated microbial community structure by improving soil physicochemical properties and plant traits, with stronger effects on fungi than bacteria. In conclusion, MBG optimizes the soil microhabitat and plant-soil-microbe interactions, modulating microbial diversity, network complexity, and functional potential. The medium ratio (1:2) was most effective, demonstrating potential for ecological restoration of degraded mine soils.

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Application of Microporous Bio-Gravel for Microecological Remediation of Degraded Mine Soils

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511025• Jan 15, 2026

Carbon Emission Accounting and Reduction Pathways for a Municipal Wastewater Treatment Plant in Lanzhou

Authors: XU Wen, YANG Rui, LIU Xiangrui, MAO Yaoru, CHENG Xiuwen

Under the national carbon peak and carbon neutrality goals, carbon reduction in municipal wastewater treatment plants (WWTPs) has been largely overlooked, yet accurate accounting is the first step toward mitigation. This study establishes a carbon emission accounting method for a municipal WWTP in Lanzhou, covering the operation and maintenance phase, to identify key emission sources and propose feasible reduction pathways. The results show that the total annual carbon emission in 2023 was 61,399.80 t CO2-eq, with an emission intensity of 0.71 kg CO2-eq per tonne of wastewater treated. Monthly emissions were relatively stable, with a coefficient of variation of 3.46%. Direct emissions accounted for 47.47% of the total, with N2O being the dominant contributor (61.89% of direct emissions), followed by CO2 (30.88%) and CH4 (7.23%). Indirect emissions accounted for 52.53%, dominated by electricity consumption (95.15% of indirect emissions). Pearson correlation analysis revealed that direct carbon emissions per tonne were significantly correlated with influent BOD5 concentration, influent TN concentration, BOD5 removal rate, and TN removal rate (P < 0.01). Sensitivity analysis identified sewer retention time, fossil carbon fraction in influent, and solids retention time as the most influential parameters, with sensitivity coefficients of 0.42, 0.35, and 0.28, respectively. Considering uncertainties in emission factors and monitoring errors, the 95% confidence interval for annual total emissions was 55,200–67,600 t CO2-eq, corresponding to an emission intensity of 0.64–0.79 kg CO2-eq per tonne. Recommendations focus on three synergistic reduction strategies: reducing source emissions, lowering energy consumption, and enhancing carbon compensation.

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Carbon Emission Accounting and Reduction Pathways for a Municipal Wastewater Treatment Plant in Lanzhou

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202509120• Jan 15, 2026

Intensity-Based Carbon Reduction Benefits of 'Zero-Waste City' Construction: A Case Study of Mianyang

Authors: LONG Fei, JIANG Zhonglin, TANG Xiujuan, JIANG Yingying, DING Xia, CHEN Mengjun, JU (Corresponding Author: CHEN Mengjun)

The 'Zero-Waste City' initiative, centered on source reduction, resource utilization, and safe disposal of solid waste, aims to minimize environmental impact. To quantitatively assess its carbon reduction contribution, this study took Mianyang as a case, systematically collecting data on solid waste generation, utilization, and disposal across industrial, agricultural, and other sectors from 2021 to 2024. Employing an improved WARM model and emission factor method, and incorporating generation, utilization, and disposal intensities, the carbon reduction benefits before (2021–2022) and after (2023–2024) the initiative were evaluated. Results show that despite significant improvements in comprehensive utilization and safe disposal rates, total solid waste generation increased, leading to a net negative carbon effect of -127.6×10^4 tCO2eq based on absolute quantities. However, after stripping economic and population growth factors, intensity-based accounting revealed a cumulative reduction of 10.8×10^4 tCO2eq, demonstrating significant synergistic benefits. The industrial sector contributed the most, with a reduction of 40.2×10^4 tCO2eq, driven by green transformation and enhanced utilization capacity. Conversely, the rising intensity of domestic solid waste generation resulted in a negative benefit of -46.1×10^4 tCO2eq, highlighting a key area for future improvement. The study underscores the necessity of considering both intensity and absolute quantity dimensions in evaluating rapidly developing cities. These findings provide practical evidence and reference pathways for advancing 'Zero-Waste City' construction and synergistic pollution reduction and carbon mitigation under the 'dual carbon' goals.

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Intensity-Based Carbon Reduction Benefits of 'Zero-Waste City' Construction: A Case Study of Mianyang

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511021• Jan 15, 2026

Synergistic Cadmium Immobilization in Paddy Soil by Klebsiella aerogenes Wn Combined with Hydroxyapatite

Authors: ZHAI Ke, SU Yuan, GUAN Huize, TANG Xi, RAO Zhongxiu, HUANG Fengqiu, TANG Chongjian

Phosphate-solubilizing microorganisms (PSM) can immobilize cadmium (Cd) by dissolving insoluble phosphates and inducing the precipitation of stable Cd-phosphate minerals. However, the low bioavailability of soil phosphorus and the relatively low Cd2+ concentrations often limit the efficiency of microbial-induced phosphate precipitation (MIPP). This study proposed a combined strategy using the phosphate-solubilizing bacterium Klebsiella aerogenes Wn (Wn) and hydroxyapatite (HAP) to enhance Cd immobilization in paddy soil. Pot experiments were conducted to evaluate the effects on soil Cd availability and rice grain Cd accumulation, and the underlying mechanisms were investigated. Results showed that the combined treatment stabilized soil pH between 5.8 and 6.7 and electrical conductivity between 66 and 290 μS·cm−1, while increasing available phosphorus by 4%–67%. The optimal treatment (T4: 8 g·kg−1 HAP + 3.75×10^9 cfu·kg−1 Wn) reduced soil available Cd by 40.2% and decreased rice grain Cd to 0.0699 mg·kg−1, which is 65% below the national food safety limit. Microbial community analysis confirmed successful colonization of Wn. Pure culture experiments demonstrated that Wn induced phosphate precipitation, forming a more stable cadmium hydroxyapatite mineral [Ca3.9(Ca4.7Cd0.7)(PO4)6(OH)1.8]. The combined Wn-HAP treatment is an efficient strategy for remediating Cd-contaminated farmland, with significant potential for ensuring agricultural product safety and promoting soil remediation.

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Synergistic Cadmium Immobilization in Paddy Soil by Klebsiella aerogenes Wn Combined with Hydroxyapatite

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511054• Jan 15, 2026

S-scheme Bi6O5(OH)3(NO3)5·3H2O/BiOBr0.8I0.2 Heterojunction Photocatalyst: Synthesis and Visible-Light Degradation Mechanism of Rhodamine B

Authors: LI Dongmei, HE Shuai, JIANG Shuxian, CHEN Zhixiang, WU Hanjie, ZHANG Jinming, DAI Ziqiang, LIU Ziye

A novel S-scheme heterojunction photocatalyst, Bi6O5(OH)3(NO3)5·3H2O/BiOBr0.8I0.2 (BON@BI), was synthesized via a one-step hydrothermal method using Bi6O5(OH)3(NO3)5·3H2O (BON), KBr, and KI as precursors. The mass ratio of BON to BiOBr0.8I0.2 (BI) was optimized, revealing that the 20% BON@BI composite (BON@BIOPT) exhibited the highest visible-light photocatalytic activity. Under 30 min of visible-light irradiation, BON@BIOPT achieved a 99.8% degradation efficiency of Rhodamine B (RhB), approximately twice that of pristine BI (52.2%). The composite displayed a rod-like morphology with uniform nanosheets, and its specific surface area increased from 32.54 m²·g⁻¹ (BI) to 44.7 m²·g⁻¹. The absorption edge red-shifted from 560 nm (BI) to 580 nm, narrowing the bandgap from 2.55 eV to 2.43 eV. The S-scheme heterojunction formed between BON and BI generates an internal electric field that effectively suppresses recombination of strongly reducing photogenerated electrons and strongly oxidizing holes, with superoxide radicals (O₂•⁻) and holes (h⁺) identified as the primary reactive species. BON@BIOPT exhibited excellent stability, retaining 88.6% degradation efficiency after seven consecutive cycles. It also demonstrated robust environmental adaptability, maintaining 85–98% degradation efficiency under various pH conditions and in the presence of interfering anions. The degradation pathway of RhB involves N-de-ethylation, cleavage of the conjugated chromophore, and deamination, ultimately mineralizing into low-molecular-weight organics, inorganic salts, CO₂, and H₂O. These results underscore the potential of BON@BIOPT for practical remediation of organic pollutants in water.

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S-scheme Bi6O5(OH)3(NO3)5·3H2O/BiOBr0.8I0.2 Heterojunction Photocatalyst: Synthesis and Visible-Light Degradation Mechanism of Rhodamine B

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511046• Jan 15, 2026

Comparative Carbon Footprint of Ex-situ Remediation Facility and On-site Remediation Modes for Contaminated Soil

Authors: LI De'an, DENG Yirong, LI Fuhan, ZHANG Zhenxing, LI Shuo, WANG Jun

To evaluate the carbon footprint differences between the emerging ex-situ remediation facility mode and the conventional on-site remediation mode in China, this study employed the SEFA tool to calculate greenhouse gas (GHG) emissions and energy consumption for four typical remediation scenarios. Results indicate that the carbon emission intensity of solidification/stabilization (S/S) in the remediation facility is 12.00% higher than that of on-site S/S, with unit carbon intensities of 66.74 and 59.59 kgCO2e·m−3, respectively, and total energy consumption 11.90% higher. The soil transport segment in the facility S/S contributes 13% of carbon emissions, being the primary reason for its higher total carbon footprint. Conversely, thermal desorption (TD) in the facility exhibits 11.10% lower carbon emissions than on-site TD, with unit intensities of 269.16 and 302.78 kgCO2e·m−3, and total energy consumption 3.97% lower, mainly due to the utilization of landfill biogas as renewable energy for heat and power generation, while soil transport contributes only 3% of emissions. The reagent segment in S/S and the heat supply segment in TD account for 77%–86% and 70%–72% of total GHG emissions, respectively. The study demonstrates that remediation facilities, leveraging advantages such as landfill biogas, can actively aggregate contaminated soil from surrounding areas for centralized thermal desorption, which is beneficial for regional carbon emission reduction in soil remediation.

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Comparative Carbon Footprint of Ex-situ Remediation Facility and On-site Remediation Modes for Contaminated Soil

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202510017• Jan 15, 2026

Carbon Emission Analysis and Reduction Scenario Prediction of Municipal Solid Waste Based on LCA-SD Model

Authors: ZHAO Hui, LIN Xiaoying, JIANG Wei, HUANG Hanwei, CAO Xinchong, CHEN Junjun, LIU Xueping

Municipal solid waste (MSW) is a significant source of urban carbon emissions. This study integrates life cycle assessment (LCA) and system dynamics (SD) to construct a multi-subsystem LCA-SD model covering economy, population, waste generation, transportation, treatment, and resource utilization, using Fuzhou City as a case study. The model was validated against historical data and uncertainty analysis. Carbon emissions from MSW transportation, treatment, and resource utilization during 2013–2023 were calculated, and emission trends under seven reduction scenarios for 2024–2035 were predicted. Results show that Fuzhou's MSW treatment evolved through three stages: 'landfill+incineration', 'treatment structure adjustment', and 'incineration+kitchen waste resource utilization', corresponding to emission growth, fluctuation, and reduction periods. In 2023, total net carbon emissions were 1.07×10^6 t CO2-eq, with incineration being the largest contributor (9.93×10^5 t), followed by transportation (2.93×10^4 t), leachate treatment (2.14×10^4 t), and kitchen waste treatment (7.90×10^3 t, negative emission). Scenario analysis indicates that without further measures, carbon neutrality cannot be achieved. Synergistic enhancement of kitchen waste separation and incineration power generation efficiency can significantly boost reduction, potentially achieving carbon neutrality by 2032. The study provides a dynamic accounting and scenario assessment framework for low-carbon transition of urban solid waste systems.

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Carbon Emission Analysis and Reduction Scenario Prediction of Municipal Solid Waste Based on LCA-SD Model

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202512066• Jan 15, 2026

RuO2 Nanorods for Electrochemical Chlorine Evolution and Simultaneous Removal of Ammonia Nitrogen and COD from Wastewater

Authors: SONG Xiaoyang, WANG Yan, REN Xiaohua, ZHAO Xu

This study addresses the removal of ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) from real coal chemical wastewater via electrochemical chlorine evolution. A nanorod-structured ruthenium dioxide catalyst (N-RuO2) was synthesized by modifying ruthenium trichloride precursor with ammonium chloride. Compared with unmodified RuO2, commercial DSA, and commercial RuO2 (Com-RuO2), N-RuO2 exhibited significantly enhanced electrochemical performance: Faradaic efficiency for chlorine evolution increased by 12.9%, 18.5%, and 25.6%, respectively; accelerated lifetime improved by 1.7, 1.9, and 2.9 times, respectively. In treating real coal chemical wastewater, N-RuO2 reduced NH4+-N to 86.4 mg·L−1 and COD to 72 mg·L−1, with degradation rate constants approximately 2.08 and 1.46 times higher than Com-RuO2, while energy consumption decreased by 17.7 Wh·g−1 and 1.5 Wh·g−1, respectively. Further studies showed that increasing chloride ion concentration enhanced removal rates and reduced energy consumption; higher current density accelerated removal but increased energy use; alkaline conditions favored NH4+-N removal, while neutral conditions favored COD removal. The excellent electrochemical performance of RuO2 nanorods indicates broad application prospects in practical water treatment.

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202408057• Jan 15, 2026

Coastal Urban Waterlogging Simulation and Drainage System Optimization: A Case Study of the Shajing River Drainage Area in Shenzhen

Authors: YU Ziwei, LYU Jiajie, TIAN Zhan, YE Qinghua, WANG Yanlong, LIU Qiaodan, TANG Yingdong

Urban waterlogging, exacerbated by climate change and rapid urbanization, poses increasing risks, particularly in coastal low-lying areas with dense river networks. This study simulated waterlogging in the Shajing River drainage area of the Maozhou River basin, Shenzhen, using the SOBEK hydrodynamic model. Under a 5-year return period rainfall, 47 manholes overflowed and 31.29% of stormwater pipes operated at full capacity. Twelve waterlogging-prone points were identified: eight due to insufficient drainage capacity and five due to river backflow from low elevation. Two optimization schemes were compared: enlarging pipe diameters and implementing Low Impact Development (LID) measures. Pipe enlargement reduced overflowing manholes by 32 and full-flow pipe length by 20%, effectively decreasing surface ponding. LID measures reduced overflowing manholes by only 4 and full-flow pipe length by 1.5%, but decreased maximum flooding depth by nearly 1 m, alleviating drainage system burden. The study highlights the complex causes of coastal urban waterlogging, especially river backflow under tidal influence, and recommends considering sea-level rise and storm surge in drainage design. The findings provide valuable references for attributing waterlogging causes and planning drainage network upgrades in coastal cities.

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Coastal Urban Waterlogging Simulation and Drainage System Optimization: A Case Study of the Shajing River Drainage Area in Shenzhen

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511011• Jan 15, 2026

Continuous Manufacturing Process Design of Solid-Waste-Based Ozone Catalysts and Their Long-Term Performance Study

Authors: HUANG Yanli, LI Yanhong, JI Zehua, et al.

The high cost of catalysts is a critical barrier to the upgrading and cost reduction of catalytic ozonation technology. This study developed a low-cost, long-life Fe–Mn-based ozone catalyst (FMG) derived from solid wastes (red mud and blast-furnace slag), leveraging iron and manganese components to construct dual active centers. A continuous manufacturing process was achieved by integrating alkali-activated cementitious reactions with disc pelletization via a cascade spray-coating and multi-stage curing technique. Under optimal conditions (ozone dosage 3.5 mg·L−1), the catalyst achieved 81.81% total organic carbon (TOC) removal of phenol solution within 60 min, retaining 87.27% of its initial activity after 15 reuse cycles. Long-term continuous-flow tests over 60 days demonstrated stable TOC removal between 69.44% and 75.46%. The production cost of FMG was 1,351.44 CNY·t−1, and the unit TOC removal cost was only 0.06 CNY·(g TOC)−1, representing a 78.69%–86.85% reduction compared to commercial catalysts (0.30–0.48 CNY·(g TOC)−1). This work provides a theoretical and technical foundation for cost-effective catalytic ozonation and high-value conversion of bulk solid wastes.

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Continuous Manufacturing Process Design of Solid-Waste-Based Ozone Catalysts and Their Long-Term Performance Study

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511050• Jan 15, 2026

Engineering Optimization of an 80 t·d−1 Municipal Solid Waste Gasification-Incineration Furnace: A Case Study in Inner Mongolia

Authors: ZHANG Zhefeng, LI Wenkai, GU Qi, LIU Jianguo, SHI Lin, ZHANG Jialong, WANG Qunhui, MA Lisha, ZHENG Tianlong

Municipal solid waste (MSW) management in Inner Mongolia has long relied on landfilling, facing land scarcity and leachate management challenges. This study addresses the region's dry, cold climate, high proportion of agricultural and livestock waste, fluctuating moisture content, and weak leachate treatment capacity. An engineering optimization was implemented on an 80 t·d−1 vertical rotary gasification-incineration system featuring a dual-combustion-chamber design (primary chamber for medium-temperature pyrolysis-gasification at 550–650 °C and secondary chamber for high-temperature oxidation above 900 °C), coupled with in-situ leachate recirculation. Field measurements showed improved processing capacity and continuous operation stability. Under the project's leachate yield, in-situ recirculation achieved on-site disposal without significant adverse effects on gasification-incineration conditions, providing buffering against moisture fluctuations. During the monitoring period, major gaseous pollutant emissions remained below current national standards. The results provide engineering references for the co-processing and stable operation of small-scale county-level MSW treatment facilities.

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Engineering Optimization of an 80 t·d−1 Municipal Solid Waste Gasification-Incineration Furnace: A Case Study in Inner Mongolia

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511094• Jan 15, 2026

Effect of Fermentation Temperature on Volatile Fatty Acid Production and Fungal Community Structure from Brewer's Spent Grain

Authors: HONG Wenfei, XU Yufeng, TONG Juan, WEI Yuansong, CHEN Hexiang

Brewer's spent grain (BSG), a major byproduct of the brewing industry, is produced in large quantities globally, yet its high-value utilization remains limited. This study investigated the effects of fermentation temperature (35, 40, 45, 50, and 55 °C) on volatile fatty acid (VFA) production and fungal community structure during anaerobic fermentation of BSG. Results showed that mesophilic temperatures significantly enhanced VFA yields, with the highest production at 35 °C, reaching 344.22 mg/g COD converted, and a peak VFA concentration of 14,267 mg/L after 5 days. Acetic acid dominated the VFA profile (95.6%–98.9%) across all temperatures. Protein and carbohydrate degradation rates were highest under mesophilic conditions, while lipid degradation peaked at 55 °C. Fungal community analysis revealed that at peak acid production, cellulose-degrading fungi were predominant, with Oligophagozyma being the dominant genus at 35 °C (90.07%) and 40 °C (55.31%). Higher temperatures increased fungal diversity and evenness. Mantel tests indicated that carbohydrates and lipids promoted fungal growth, whereas total dissolved solids, nitrate, and phosphate inhibited it. These findings provide insights into the role of fungi in VFA production from BSG and support its resource utilization.

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Effect of Fermentation Temperature on Volatile Fatty Acid Production and Fungal Community Structure from Brewer's Spent Grain

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511052• Jan 15, 2026

Effects of Different Morphologies of PET Microplastics on Anaerobic Digestion of Sewage Sludge

Authors: MA Yuhui, XIA Ziyuan, GOU Min, TANG Yueqin

Microplastics in sewage sludge, owing to their diverse physicochemical properties, can differentially affect subsequent anaerobic digestion. This study focused on polyethylene terephthalate (PET) microplastics, systematically investigating the effects of particle (MP), fiber (MF), and film (MPF) morphologies at concentrations of 0–150 mg·g⁻¹ (based on total solids) on sludge digestion performance and microbial community structure. Results showed that MP inhibited total biogas production at all concentrations (inhibition rates 8.16%–9.58%), whereas MF and MPF exhibited low-concentration stimulation and high-concentration inhibition, with MPF exerting stronger inhibition than MF. All MP concentrations induced significant reactive oxygen species (ROS) accumulation (increases of 9.43%–34.52%), indicating the strongest oxidative stress. Low concentrations of PET generally enhanced cell membrane permeability, prompting microbes to secrete different extracellular polymeric substances (EPS) to resist stress. The morphology and concentration of microplastics regulated the relative abundances of key functional bacteria (e.g., proteolytic bacteria and organic acid-oxidizing bacteria) and low-abundance bacteria, ultimately leading to differences in digestion performance. This study provides a theoretical basis for efficient treatment of sludge containing microplastics.

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Effects of Different Morphologies of PET Microplastics on Anaerobic Digestion of Sewage Sludge

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Original ResearchVol. 20, Issue 7 • pp. 100-112DOI: 10.12030/j.cjee.202511062• Jan 15, 2026

Application and Mechanistic Study of Lactate Regulation and Microbial Immobilization Technology in Sediment Microbial Fuel Cell Systems

Authors: YU Jianjun, QI Jiarui, WU Yutiancheng, LI Xiaofeng, XIE Wen, WU Chenyang

Sediment microbial fuel cells (SMFCs) are a green technology for simultaneous polluted sediment remediation and energy recovery, yet their performance is constrained by insufficient anodic microbial activity and low electron transfer efficiency. This study employed lactate addition combined with composite engineered microbial immobilization to synergistically optimize SMFC performance by enhancing microbial stability and carbon source supply. Results showed that lactate, as an easily utilized electron donor, promoted electrochemical activity, achieving a maximum power density of 22.06 mW·m−2 at 6 mmol·L−1, a 194% improvement over the blank group. Immobilization further enhanced electron transfer efficiency, with the highest output voltage (88.75 mV) being 2.09 times that of the non-immobilized group. For pollutant degradation, the 6 mmol·L−1 lactate group achieved TOC and TN removal rates of 29.02% and 28.4%, respectively, outperforming the control (22.41% and 21.42%). However, high lactate concentrations inhibited microbial metabolism, leading to TOC accumulation. 16S rRNA analysis revealed that the anodic microbial community was dominated by Bacillota and Pseudomonadota, both possessing electroactive and pollutant-degrading capabilities, indicating that lactate and immobilization exert a synergistic effect in SMFCs, simultaneously enhancing electricity generation and pollutant removal efficiency.

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Application and Mechanistic Study of Lactate Regulation and Microbial Immobilization Technology in Sediment Microbial Fuel Cell Systems

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