Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507029
This study systematically evaluates the environmental risks associated with the resource utilization of municipal solid waste incineration (MSWI) fly ash in the production of aerated concrete, co-prepared with multiple solid wastes. The focus is on the leaching behavior and total content of heavy metals (Cr, Pb, Cd, Cu, Zn) under CO2 curing and chelating agent stabilization. Water washing pretreatment parameters (liquid-to-solid ratio, washing time, ash-to-slag ratio) were optimized for chloride removal. Results demonstrate that CO2 curing suppresses the leaching of most metals; leaching concentrations of Cr, Pb, Cd, and Zn decrease with reduced fly ash content, whereas Cu leaching increases when fly ash is absent. The addition of 17.5% organic sulfur stabilizer (DTC) significantly outperforms inorganic sulfide (Na2S) in immobilizing heavy metals, achieving compliance with national standards without compromising compressive strength or carbon sequestration. Water washing effectively reduces soluble chloride content to below 1% (mass fraction), meeting the HJ 1134-2020 regulatory limit. Optimal parameters include a liquid-to-solid ratio of 5, washing time of 20 min, and a raw material ratio of incineration bottom slag:fly ash:slag = 40:20:40. Under these conditions, the final product exhibits a compressive strength of 1.50 MPa, with heavy metals and soluble chlorides fully compliant. This work provides key technical support for the safe recycling of MSWI fly ash in building materials.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605001
The lower reaches of the Yangtze River Basin, as a concentrated area of China's C5 petroleum resin industry, face critical bottlenecks in green and low-carbon transformation due to high-pollution, refractory wastewater and high carbon emissions. Traditional petrochemical wastewater treatment technologies suffer from low efficiency, high energy consumption, and insufficient resource utilization. This paper systematically analyzes the sources of wastewater in C5 petroleum resin production from principles and processes, and reviews research progress and carbon reduction potential of current technologies in three aspects: new materials, new equipment, and new processes. Integrated processes centered on efficient pretreatment, biological enhancement, and multi-technology coupling show significant advantages in improving treatment efficiency, reducing energy consumption and cost, and strengthening resource recovery. The study also prospects future research priorities for pollution and carbon mitigation through green technological innovation and intelligent upgrading, providing new solutions for 'near-zero discharge' and resource recycling of C5 petroleum resin wastewater, thereby promoting the green and low-carbon transformation of the petrochemical industry.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509020
The AAOA-MBR (anaerobic-anoxic-oxic-anoxic membrane bioreactor) process is widely used in municipal wastewater treatment, but its multi-stage internal recirculation complicates sludge retention time (SRT) and carbon source distribution. This study systematically regulated three reflux ratios (R1: membrane tank to oxic tank; R2: oxic tank to anoxic I tank; R3: anoxic II tank to anaerobic tank) in a pilot-scale system (0.24 m3·d−1) to reveal their effects on nutrient removal and membrane fouling. When R1:R2:R3 = 300%:200%:100%, effluent COD, TN, TP, and NH3-N met discharge standards. Reducing R1 and R2, thereby decreasing total reflux ratio from R=6 to R=3, shortened SRT, which suppressed nitrifier accumulation and increased effluent COD and TN, but decreased TP. High-throughput sequencing of anoxic I and oxic tanks showed that denitrifying bacteria (Thauera and Ottowia) relative abundances decreased from 0.68% to 0.42% and 0.51% to 0.24%, respectively, while the phosphorus-accumulating organism Candidatus_Accumulibacter increased from 0.78% to 1.12%, enhancing phosphorus removal. Additionally, lowering R1 to 200% caused sludge accumulation in the membrane tank, exacerbating membrane fouling. Thus, internal recirculation ratios must be adjusted based on influent characteristics to balance nutrient removal and membrane performance.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607003
Co-firing municipal sludge with municipal solid waste (MSW) provides a viable solution for sludge disposal. This study evaluated the effect of sludge co-firing rate (0%, 5%, and 10%) on flue gas pollutant emissions, operational performance, and incineration byproduct characteristics in a waste-to-energy plant. The results showed that under all co-firing rates, the concentrations of SO2, NOx, CO, HCl, particulate matter, and dioxins complied with the limits specified in the Standard for Pollution Control on Municipal Solid Waste Incineration (GB 18485—2014). As the co-firing rate increased from 5% to 10%, concentrations of all flue gas pollutants except NOx and HCl exhibited an upward trend. The optimal operational performance under the test conditions was achieved at a 5% co-firing rate, when the flue gas volume, fan volume, and ammonia and lime consumption were minimized. Compared to the 5% rate, increasing the co-firing rate to 10% resulted in elevated flue gas volume, fan volume, and reagent consumption. Steam production decreased from 2.778 t/t (0% co-firing rate) to 2.358 t/t (5% co-firing rate) and 2.117 t/t (10% co-firing rate), indicating a reduction in power generation efficiency with increasing sludge co-firing rates. Leaching toxicity analysis of fly ash revealed significant reductions in the leached concentrations of Zn and Pb, while those of Hg, As, Ba, and Se showed slight increases, all remaining well below regulatory limits. This study confirms the technical feasibility of directly co-firing mechanically dewatered sludge (with a moisture content of 50% to 60%) without thermal drying. A 5% co-firing rate is identified as the optimal balance between operational economy and system efficiency.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511094
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.