Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607018
To address the dual challenges of phosphorus resource scarcity and eutrophication control, this study proposed a sustainable waste-treats-waste strategy by preparing red-mud-modified sludge-based biochar (RMSBC) via co-pyrolysis of red mud and sewage sludge. The optimal material (RMSBC800), produced at 800 °C with a red mud-to-sludge mass ratio of 3:1, achieved a maximum phosphorus adsorption capacity of 28.57 mg/g, a 350% enhancement over unmodified biochar (SBC). Characterization (SEM, XRD, EDS, FT-IR, XPS) revealed that red mud modification increased the average pore size from 7.91 nm to 20.33 nm, reduced electronegativity, and raised the pH at point of zero charge (pHpzc) from 2.01 to 3.37. Adsorption kinetics followed the pseudo-second-order model, and isotherms fitted the Langmuir model, indicating monolayer chemisorption. The Freundlich parameter 1/n was 0.34, suggesting favorable adsorption. Mechanistic studies identified electrostatic attraction and surface precipitation as dominant, with molecular dynamics simulations confirming the critical role of Fe3O4 over Fe2O3 in adsorbing HPO4^2- due to stronger electrostatic interactions. The material retained 61% of its initial capacity after five regeneration cycles and achieved 83% phosphorus removal from real wastewater. This work demonstrates synergistic valorization of industrial wastes, offering an economically viable solution for phosphorus pollution control and resource recovery.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202408057
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.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608025
To evaluate heavy metal contamination and human health risks in desert lakes, this study analyzed concentrations of seven heavy metals (Hg, Pb, Cu, Zn, Cd, Cr, As) in Hongjiannao Lake, Northern Shaanxi, from 2013 to 2024. The absolute principal component score-multiple linear regression (APCS-MLR) model quantitatively apportioned pollution sources, and a health risk assessment model evaluated non-carcinogenic and carcinogenic risks. Results showed average concentrations of the seven metals did not exceed background values, but 28.57% of sampling points exceeded background for As, with a maximum exceedance factor of 1.92. Total average concentration decreased from 112.51 μg/L (2013–2016) to 58.80 μg/L (2017–2024), attributed to the 2016 closure of small coal mines and ecological restoration around the 4A scenic area. Source apportionment identified four sources: industrial (35.44%), agricultural (24.67%), natural (23.65%), and traffic (16.23%), indicating industrial dominance. Non-carcinogenic risks were negligible, but carcinogenic risks exceeded the alert value (1×10⁻⁴), with adults at higher risk than children. Oral ingestion was the primary exposure pathway. As and Cd were key control elements, with exceedance rates of 100% and 16.67%, respectively. These findings provide a theoretical basis for health risk prevention and environmental management.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60721-9
Methane (CH4), the primary component of natural gas, is an ideal feedstock for producing high-value chemicals and clean fuels due to its high hydrogen-to-carbon ratio. However, its chemical inertness poses significant challenges, and traditional thermal catalytic reforming processes suffer from long reaction pathways and high energy consumption. Photocatalytic technology enables highly selective CH4 conversion under mild conditions, even at room temperature, offering environmental and economic benefits. This review systematically summarizes recent advances in room-temperature photocatalytic systems for direct CH4 conversion. It begins by elucidating the mechanisms, product distributions, and inherent challenges of four key reaction pathways: partial oxidation, non-oxidative coupling, oxidative coupling, and oxidative carbonylation. The discussion then addresses the critical role of catalyst architecture, focusing on semiconductor supports, metal site modulation, and advanced porous frameworks. Furthermore, reactor design and process intensification strategies are examined, including batch and continuous-flow reactors, novel structured reactors, and photo-electro and photo-thermo synergistic approaches. Finally, reaction mechanisms are summarized. Despite progress, challenges remain in fundamental understanding, performance evaluation, and technological integration. Future efforts should focus on mechanistic studies, standardization of evaluation protocols, development of non-noble metal catalysts, system optimization, and comprehensive sustainability assessments.