SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3865-1
Seawater electrolysis (SWE) is a reusable and convenient avenue for producing hydrogen, offering a promising solution to the energy crisis and global warming. However, poor electrolytic efficiency and irreversible corrosion caused by high concentrations of chlorine severely hinder the commercialization of SWE. To address these challenges, numerous strategies have been proposed in recent years, involving theoretical innovations, directional catalyst design, and electrolyser modification. This review provides a systematic summary of the chlorine-related challenges and solutions encountered in SWE. The chlorine-related theoretical knowledge and challenges in SWE systems are first emphasized. Subsequently, multiple anodic chloride suppression strategies are introduced from three aspects: directional regulation of oxygen evolution catalysts, optimization of electrolyte compositions, and ingenious upgrades of electrolytic cells. Finally, future challenges and development directions for large-scale application of SWE technology are explored. This review offers an in-depth analysis of the chlorine-related challenges encountered in the industrialization of SWE, aiming to accelerate the advancement of this technology toward practical applications.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507051
This study investigated the dynamic characteristics and recovery of ammonia emissions from a growing-finishing pig house in Yanshi District, Luoyang City, Henan Province, China. High-sensitivity electrochemical sensors and an ammonia absorption recovery device were employed for continuous monitoring and treatment of exhaust air. The results revealed periodic fluctuations in ammonia emission concentrations, strongly correlated with indoor temperature and humidity. Over the entire monitoring period, the average daily ammonia concentration in exhaust air was 9.852 mg·m−3, below the national emission limit of 25 mg·m−3. However, during high-temperature periods (>30 °C), localized concentrations reached 38.36 mg·m−3. Humidity, particularly from spray cooling, temporarily suppressed ammonia volatilization, but its effect was modulated by temperature. Total ammonia emitted during the study was 1380.4 kg, with an average per-pig emission rate of 0.034 kg·d−1. After treatment with the exhaust gas absorption device, the average daily ammonia concentration dropped to 0.437 mg·m−3, achieving a mean recovery efficiency of 93.5%. These findings demonstrate that controlling environmental factors and employing external air absorption devices can significantly reduce ammonia emissions, offering a viable pathway for mitigating nitrogen pollution from livestock operations and promoting resource recovery.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605004
To address the decline in operational performance of sewage pipeline networks in rainy cities of southern China caused by structural defects, stormwater-sewage cross-connections, and external water intrusion, a systematic governance framework comprising precise investigation, dynamic regulation, graded rehabilitation, and smart operation and maintenance was established. A zoned priority evaluation model was developed with comprehensive problem severity (P) and governance contribution (B) as core indicators, based on which differentiated governance strategies were formulated. Supported by a digital platform, monitoring, assessment, rectification, and verification data were integrated to develop a digital twin system for the pipeline network, and a correlation-based analysis and closed-loop operation and maintenance mechanism linking rainfall, groundwater level, and network hydraulic load was established. A typical urban area in Jiangxi Province was selected as the case study. After implementation, the mean COD concentration of terminal sewage in the study area increased steadily to above 230 mg/L, the average daily external water volume in the dry season decreased by 27.64%, and the sewage collection rate increased to 76%. The results indicate that the proposed framework can effectively support the quality and efficiency improvement of sewage pipeline networks in rainy cities of southern China, and provide a technical reference for similar cities.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605013
The escalating eutrophication of aquatic systems has intensified algal blooms, leading to substantial release and accumulation of algal-derived dissolved organic matter (ADOM), which profoundly influences carbon cycling and pollutant transport. Iron minerals, particularly ferrihydrite, are recognized as critical mediators of DOM sequestration, yet the adsorption fractionation of ADOM under varying environmental conditions remains poorly understood. This study systematically investigated the effects of pH (2.0–10.0) and initial dissolved organic carbon (DOC) concentration (2–100 mg C/L) on the adsorption capacity and selectivity of ADOM onto ferrihydrite, employing UV-Vis spectroscopy and excitation-emission matrix fluorescence with parallel factor analysis (EEM-PARAFAC). Results demonstrated that adsorption capacity increased with pH from 2.0 to 7.0, reaching a maximum of 21.59 mg C/g at pH 7.0, followed by a decline at pH > 7.0 due to enhanced electrostatic repulsion. Within the environmentally relevant pH range of 3.0–9.0, selective fractionation intensified with increasing pH, favoring highly aromatic, high-molecular-weight chromophoric DOM (CDOM) and protein-like/aromatic amino acid fluorescent DOM (FDOM) with high humification and autochthonous characteristics. With increasing initial DOC concentration, adsorption exhibited non-linear growth, with preferential uptake of low-aromaticity, high-molecular-weight CDOM and protein-like FDOM of lower humification and stronger autochthonous features. These findings elucidate that ferrihydrite can effectively sequester reactive ADOM components via pH- and concentration-dependent selective adsorption, potentially altering DOM composition and reactivity in eutrophic waters, thereby providing fundamental data for understanding iron mineral-mediated internal carbon sequestration.