Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024102403
The rapid combustion of soot at low temperatures is critical for diesel engine cold-start emission control. This study investigates the effects of water vapor (H2O) and nitrogen oxides (NOx) on electricity-pulse-sparked catalysis (EPSC) for soot combustion over a ceramic filter paper-based potassium-supported antimony-doped tin oxide (K/ATO/CP) monolithic catalyst. Under EPSC with 2000 J pulses, the presence of H2O and NOx adversely affected soot combustion performance, yet average reaction rates remained high at 12.0 μmol·gcat−1·s−1 and 9.53 μmol·gcat−1·s−1, respectively, exceeding conventional thermal catalysis (<8 μmol·gcat−1·s−1). In situ Raman and concentration profiles revealed that electricity pulses promote rapid H2O desorption, effectively alleviating H2O poisoning and restoring catalyst activity. In contrast, NOx adsorption forms stable nitrates (e.g., KNO3) that desorb slower than the soot combustion process, leading to incomplete recovery of activity. These findings highlight the importance of adsorbate desorption kinetics in EPSC and suggest that using weakly basic alkaline-earth metals (e.g., Mg, Ca, Sr) with lower nitrate decomposition temperatures could mitigate NOx poisoning. The results provide guidance for advancing EPSC technology in hybrid vehicle exhaust aftertreatment systems.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202605002
The single-phase partial nitrification and anammox (SPN/A) process has seen limited widespread application due to its slow startup and difficulties in enriching anaerobic ammonium-oxidizing bacteria (AnAOB). This study utilized high-ammonia nitrogen wastewater to initiate and enhance the SPN/A process in a pilot-scale integrated fixed-film activated sludge (IFAS) reactor. By establishing an IFAS-SPN/A coupled system based on the symbiotic relationship between biofilm and sludge, rapid startup and efficient AnAOB enrichment were achieved. An innovative sludge inoculation strategy was employed: first, conventional nitrifying sludge was inoculated to initiate shortcut nitrification and allow ammonia-oxidizing bacteria (AOB) to colonize blank carriers; subsequently, anammox sludge was inoculated to promote efficient AnAOB enrichment on the AOB biofilm. The influent was low-temperature shift condensation water from a synthetic ammonia workshop, with an average ammonium nitrogen concentration of 2300 mg/L and COD ranging from 50 to 200 mg/L. The 180-day experiment comprised three stages: shortcut nitrification startup, SPN/A startup, and load intensification. The system successfully started up SPN/A within 120 days, achieving total nitrogen removal efficiency and removal load of (90.21±2.18)% and (0.31±0.07) kg/(m³·d), respectively, through synergistic biofilm and suspended microorganisms. During load intensification, AnAOB relative abundances in biofilm and flocs reached 18.8% and 35.3%, respectively, and removal load increased to (0.64±0.11) kg/(m³·d). Stable influent quality is a prerequisite for efficient and stable nitrogen removal; a surge in influent ammonium concentration caused nitrite accumulation imbalance and deteriorated performance. Adding an equalization tank before the aeration tank mitigates water quality fluctuations, and a 'dilution-reconstruction' strategy for low-ammonia wastewater facilitates rapid recovery after performance deterioration.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025092801
Urban river water quality is critically influenced by outfall discharges, yet the seasonal dynamics of dissolved organic matter (DOM) and its linkage to water quality remain poorly constrained. This study collected outfall water samples seasonally during 2023–2024 along the Nanfei River and Banqiao River in Hefei, Anhui Province. Parallel factor analysis of excitation-emission matrices identified three fluorescent components: fulvic acid-like C1, tryptophan-like (protein-like) C2, and terrestrial humic-like C3. Seasonal variations were pronounced: protein-like C2 dominated in winter and spring, whereas summer and autumn showed lower C2 proportions due to rainwater dilution and urban nonpoint source runoff inputs. Water quality indices decreased in summer and autumn, primarily attributed to dilution by rainfall runoff. Fluorescence index (FI > 1.9) and biological index (BIX > 1.0) indicated predominantly autochthonous DOM sources. During summer and autumn, humification index (HIX) and specific UV absorbance (SUVA) increased, while spectral slope ratio (SR) decreased, suggesting enhanced terrestrial and urban runoff influence. Significant positive correlations were observed between protein-like C2 and terrestrial humic-like C3 with water quality parameters, indicating their utility as precise indicators of pollution sources and seasonal water quality variations. These findings provide a scientific basis for integrated management of urban outfalls.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607009
Resource utilization of food waste is a key measure for implementing waste classification and constructing zero-waste cities in China. However, the technical route based on anaerobic digestion currently faces developmental bottlenecks. In this study, engineering-scale facilities located in Northeast, North, Northwest, and Southeast China were selected, and material flow analysis was employed to comprehensively assess the current status of anaerobic digestion of food waste. The results indicated that, during the pretreatment stage, both leachate and organic slurry from all surveyed regions exhibited high COD/TN ratios, and the leachate contained high concentrations of lipids. Following three-phase (oil-water-solid) separation, the oil recovery rate could reach over 98%. Anaerobic digestion of each ton of food waste from the four regions generated approximately 70 to 80 Nm³ of biogas, while simultaneously producing liquid digestate accounting for 69% to 80% of the total mass and solid digestate accounting for 2.7% to 3.6%. However, the annual continuous production of digestate was not aligned with the seasonal demand for land use, thereby restricting the pathway for resource utilization. Converting food waste into an external carbon source can significantly enhance its resource utilization efficiency, with the economic benefits increasing by more than 203% compared to the methanogenesis pathway. The selection of the carbon source production technology route should be comprehensively determined by taking into account factors such as the specific nitrogen removal requirements of the target wastewater treatment process, the quality requirements for the carbon source products, and the substitution rate of commercial carbon sources.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025041505
To combat severe air pollution, China has implemented a series of air pollution control action plans since 2013, effectively alleviating PM2.5 pollution. However, PM2.5 concentrations in most cities within the Fenwei Plain still exceed national standards. This study systematically evaluates PM2.5 concentration changes across two policy phases (2013–2020) using the Community Multiscale Air Quality (CMAQ) model, quantifying contributions of meteorology and emissions, and analyzing sectoral source changes. Results show that annual average PM2.5 concentration declined cumulatively by 19% during 2013–2020. In the first phase (2013–2017), regional PM2.5 decreased by 3% annually, with most improvement in winter; however, due to unfavorable meteorology, concentrations increased in Xi'an and Xianyang. In the second phase (2017–2020), PM2.5 declined by an additional 16%, with more effective control measures, particularly in spring and autumn. Emission reductions dominated in both phases, with stronger effects in the second phase (−8 μg·m−3), significantly outweighing adverse meteorological contributions (+3.5 μg·m−3). Nevertheless, many cities still face challenges from unfavorable meteorology, highlighting the need for future policies to account for meteorological influences. Emissions from industrial, energy, and agricultural sources decreased significantly across both phases. However, during winter heating periods, residential emissions emerged as a source equal in importance to industrial emissions, becoming a key target for future emission controls.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60668-8
A series of Co-based molecular sieve catalysts with varying Si/Al ratios was synthesized via impregnation. Microstructural properties of Co active sites were characterized by XRD, TEM, Raman, H2-TPR, Py-FTIR, and XPS. Results indicate that surface Co species predominantly exist as CoOx nanoclusters and isolated Co2+, with the latter exhibiting superior N2O decomposition activity. Decreasing the Si/Al ratio of the MFI zeolite promotes the formation of isolated Co2+ active sites, thereby enhancing catalytic performance. Compared to Co/S-1 (pure silica support), the Co/HZ60 catalyst (low Si/Al ratio ZSM-5) lowers the temperature for complete N2O decomposition by 80 °C and demonstrates excellent resistance to O2 and NO. The strong interaction between the zeolite framework and Co2+ inhibits oxidation to Co3+, improving N2O adsorption and activation. This work provides a rational design strategy for efficient and stable Co-based catalysts for N2O abatement in industrial tail gases.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4181-6
Green hydrogen production via electrocatalytic water splitting is pivotal for sustainable energy, yet the high cost and scarcity of platinum (Pt) catalysts impede large-scale adoption. Ruthenium (Ru)-based materials emerge as promising alternatives, but their performance requires enhancement. Two-dimensional transition metal dichalcogenides (TMDs), particularly ReS2, offer intrinsic 1T' phase with good conductivity and stability, yet suffer from inert surfaces limiting water adsorption. Here, we report a heterostructure comprising Ru nanoclusters anchored on ReS2 nanosheets (Ru/ReS2) to modulate electronic structure via d-p coupling. This design enhances water dissociation kinetics and optimizes hydrogen adsorption free energy (ΔG_H*). The Ru/ReS2 catalyst exhibits superior hydrogen evolution reaction (HER) activity in acidic media, achieving an overpotential of 47 mV at 10 mA cm−2 and a Tafel slope of 38 mV dec−1, outperforming commercial Pt/C (overpotential 54 mV, Tafel slope 45 mV dec−1). Notably, it demonstrates exceptional stability, with negligible degradation after 10,000 cyclic voltammetry cycles, contrasting with Pt/C's 54 mV overpotential increase. Density functional theory calculations reveal that d-p coupling between Ru and ReS2 optimizes the electronic structure, facilitating water adsorption and dissociation. This work provides a rational strategy for designing efficient, durable, and cost-effective HER electrocatalysts for green hydrogen production.