Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507021
The accumulation of heavy metals in soil around municipal solid waste landfills poses potential risks to human health. This study selected a municipal solid waste landfill and monitored the concentrations of eight heavy metals (Zn, Pb, Cd, Ni, Hg, Cu, As, Cr) in surrounding soil. The geo-accumulation index method was used for pollution assessment, and a health risk assessment model recommended by the USEPA, combined with Monte Carlo uncertainty analysis, was employed to evaluate the pollution status and health risks to nearby residents. Results showed that among the eight metals, Pb, Ni, and Cd exceeded risk screening values at 4.26%, 6.38%, and 4.26% of sampling points, respectively. Geo-accumulation indices indicated overall clean conditions (mean < 0), but slight pollution by Pb, Zn, Ni, Hg, and Cd at some points. Probabilistic risk assessment based on Monte Carlo simulation revealed that for both adults and children, the cumulative non-carcinogenic risk was negligible, while carcinogenic risk was acceptable. However, there was a very low probability (approximately 0.2%) of non-carcinogenic risk for children, and probabilities of unacceptable carcinogenic risk were 0.64% for adults and 3.21% for children. Nickel was the primary contributor to carcinogenic risk, and children faced higher health risks than adults. These findings provide a reference for pollution prevention and health risk management of soil around municipal solid waste landfills.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605018
To address the inadequacy of existing temporal emission allocation coefficients for oil storage, transportation, and sales sources in regions with distinct seasonal temperature variations, this study focused on a large oil depot in Northwest China. A method for establishing temperature-dependent hourly allocation coefficients for VOCs emissions was proposed, revealing a positive correlation between ambient temperature and emission coefficients. The coefficient peaked at 0.068 when temperatures exceeded 14 °C and dropped to a minimum of 0.007 below 8.5 °C. Annual VOCs emissions totaled 256.13 t, with summer contributing 108.89 t (42.51% of annual total) and winter only 12.54 t (4.90%), making summer emissions approximately 8.68 times higher than winter. Using CALPUFF dispersion modeling, dynamic source strength scenarios produced a maximum hourly concentration of 2242.7 μg/m³, a 55.12% increase over the constant source strength scenario (1445.8 μg/m³). The area of exceedance increased by 0.03 km², and the atmospheric environmental protection distance extended by 450 m, from 0 m to 450 m. These results demonstrate that conventional constant emission assumptions underestimate peak concentrations and protection distances, posing health risks to nearby residents. The study provides a scientific basis for localized emission regulation and improved environmental protection distance calculations.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510041
This study presents a full-scale engineering practice of retrofitting an idle upflow anaerobic sludge blanket (UASB) reactor into an aerobic granular sludge (AGS) system for treating low-strength municipal wastewater. The design capacity was 20,000 m3/d (maximum 24,000 m3/d), achieving separate treatment of industrial and domestic wastewater to reduce operational costs. Systematic analysis covered hydraulic capacity enhancement, effluent quality, pollutant removal efficiencies, sludge granulation progress, and operational costs. Results showed rapid start-up: the system reached 75% of design capacity by day 10 and 90% by day 26. During a 4-month operation, average removal efficiencies for COD, NH4+-N, TN, and SS were 83.2%, 97.0%, 75.9%, and 94.4%, respectively, even under low influent BOD5/TN ratios (typically below 4). Granulation progressed quickly: by day 44, average particle size was 2.6 times that of the inoculum and over 4 times that of flocs, with granules (>200 μm) accounting for 17.3%; by day 110, these values increased to 3.2 times and 5 times, with granule proportion reaching 33.4%. Compared to the previous year (June–August), the AGS process reduced electricity consumption, chemical consumption, and sludge production by 77.3%, 25.4%, and 30.4%, respectively, while saving 65.6% of footprint. This ten-thousand-ton case provides a practical basis for AGS technology application in China.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511002
To treat large-air-volume, low-concentration volatile organic compounds (VOCs) containing tetrachloroethylene (PCE) generated from rubber-metal bonding, this study systematically investigated the adsorption-desorption behavior and interaction mechanisms of PCE, toluene, and methyl isobutyl ketone (MIBK) on granular activated carbon (GAC). Static adsorption experiments showed that PCE adsorption capacity reached 556.6 mg·g−1, while dynamic multi-component adsorption capacity was 179.6 mg·g−1. Kinetic analysis indicated that PCE adsorption was controlled by both intraparticle diffusion and external surface adsorption, whereas toluene and MIBK were primarily intraparticle diffusion-limited. During high-temperature nitrogen desorption, PCE underwent dechlorination, hydrogenation, and recombination, producing trichloroethylene, 1,2-dichloroethane, 1,2-dichloropropane, and HCl, with HCl accounting for 3.61% of the chlorine molar content in adsorbed PCE. After four adsorption-desorption cycles, the iodine value of GAC dropped below the industry standard of 600 mg·g−1; however, water washing and alkali immersion extended the cycle life to 8 and 9 cycles, respectively. The HCl generation pattern in co-adsorption systems was consistent with single-PCE systems. A regeneration process combining alkali immersion and water washing was proposed and integrated into an engineering strategy. Compared to conventional activated carbon adsorption coupled with RTO incineration, the proposed classification strategy reduced annual costs by 49.5×10⁴ CNY. This work provides a cost-effective and safe solution for Cl-VOCs treatment.