Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507081
Coal chemical waste salt, a solid residue from evaporative crystallization of high-salinity wastewater, poses significant environmental risks and challenges for resource utilization due to its complex composition. This study systematically analyzes its composition and environmental hazards, highlighting its typical "mixed salt" nature and the potential threats of organic pollutants and heavy metals to soil, water, and ecosystems. It reviews mainstream treatment pathways, including organic degradation, inorganic impurity removal, and salt separation, with a focus on the resource utilization of sodium chloride and sodium sulfate and their industrial prospects. The current pollution control technical specifications and product quality standards are examined, comparing the scope and technical points of relevant standards such as the "Technical Specification for Pollution Control of Chemical Waste Salt." Finally, countermeasures are proposed to address challenges including difficult treatment of mixed salts, insufficient resource utilization incentives, and incomplete standard systems, emphasizing technological innovation, policy guidance, and standard improvement.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202508021
Coal chemical industry waste salt, generated from high-salinity wastewater treatment, poses a bottleneck for green transformation under the 'dual carbon' strategy due to its low value and high complexity. This study investigated a typical coal chemical industrial park in Northwest China, using principal component analysis (PCA) on actual waste salt samples to identify pollutant characteristics and assess resource utilization potential. Results showed total organic carbon (TOC) ranged from 707.9 to 7,737.9 mg·kg⁻¹, with benzo(a)pyrene concentrations frequently exceeding the limits of the 'Identification Standards for Hazardous Wastes' (GB 5085.3). Hardness ions and metal ions also surpassed relevant product standards. PCA classified the waste salts into three types: sodium sulfate type, sodium chloride type, and high-complexity mixed salt, each corresponding to distinct resource utilization pathways. The study proposes differentiated technical routes based on PCA classification, providing a feasible reference for classified management and technology selection. This research supports the national policy of 'harmless pretreatment + resource utilization' for waste salt, contributing to green and high-quality development of the coal chemical industry.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(25)60630-X
Chemical looping methane steam reforming (CL-MSR) enables sequential production of high-selectivity syngas and high-purity hydrogen via redox cycling, yet single iron-based oxygen carriers suffer from poor cycling stability, low reactivity, and sintering. This study modified Fe2O3/Al2O3 oxygen carriers with Cu, La, and Ce additives via dip-coating, and systematically characterized their physicochemical properties, reactivity, and hydrogen production performance. Results showed that spinel-phase CuFe2O4 exhibited higher reactivity than perovskite LaFeO3 and CeO2, promoting deeper reduction of Fe2O3. Fe58Cu2Al achieved an oxygen storage capacity of 6.5 mmol/g. During CH4 reaction, Fe58Cu2Al exhibited the highest oxygen loss of 12.1 g/100 g oxygen carrier, with syngas yield of 5.15 mmol/g—1.33 and 1.59 times that of Fe60Al. In hydrogen production, the 2% Cu-modified carrier yielded 5.13 mmol/g H2, 1.51 times that of pristine Fe60Al, with purity exceeding 98%. After ten cycles, H2 yield remained at 3.61 mmol/g, surpassing the single-cycle output of pristine Fe60Al (3.39 mmol/g), demonstrating superior dispersion and coking resistance. The study establishes Cu modification as an effective strategy to enhance reactivity and cyclic stability of iron-based oxygen carriers for CL-MSR hydrogen production.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202509055
Microbial communities are the core functional units in environmental biotechnology. Magnetic field technology, as a non-invasive physical enhancement method, has shown application potential in wastewater treatment and waste resource recovery. Traditional ecological theory posits a positive correlation between species diversity and system function/stability. However, magnetic field enhancement often coincides with improved system performance and decreased microbial diversity, indicating a decoupling. This review systematically explains this phenomenon as the result of magnetic field-driven functional specialization of microbial communities. Magnetic fields act on paramagnetic targets in energy metabolism, including iron-sulfur clusters and cytochromes, alter cell surface physicochemical properties, impose oxidative stress, and select strains with high metabolic flexibility, thereby achieving targeted enrichment of key functional groups such as ammonia-oxidizing bacteria and electroactive bacteria within Proteobacteria. Although such functionally specialized communities have reduced species richness, they exhibit higher energy metabolism efficiency, enhanced electron transfer capacity, optimized interspecies cooperation networks, and strengthened system robustness. These advantages collectively support efficient and stable macroscopic bioprocess performance. This study also discusses potential limitations regarding ecosystem resilience and scenario dependence, and envisions future directions such as quantitative modeling and synergy with magnetic materials to advance magnetic field technology from empirical application to rational design.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025050803
This study systematically investigates the synergistic drag reduction mechanism of surfactants and porous media in coal seam water injection. Four surfactant types—cationic CTAB, anionic SDBS, amphoteric BS-12, and nonionic OP-10—were tested with five porous media pore sizes (3–12 mm) using a custom-built all-in-one drag reduction test system. The effects of surfactant type, mass concentration, driving frequency, and pore diameter on drag reduction efficiency were evaluated. Results show that in an empty tube, drag reduction efficiency increases with mass concentration. As driving frequency increases, drag reduction first rises then falls, peaking at 35 Hz. With porous media, drag reduction exhibits pore size dependence, reaching a maximum at 8 mm and decreasing thereafter. The composite surfactant-porous media system achieves synergistic enhancement over single systems. At 0.05% mass concentration, all surfactants attain maximum drag reduction, with CTAB showing the highest efficiency. Optimal conditions (0.05% CTAB, 35 Hz, 8 mm pore size) yield a drag reduction rate of 66.14%, a 1.4-fold improvement over 20 Hz. These findings demonstrate that tailoring surfactant and porous media parameters can significantly optimize coal seam water injection efficiency, offering a practical approach for dust control in mining.