Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(25)60616-5
CuZnAl (CZA) is a classic industrial catalyst for methanol synthesis from syngas, but its catalytic performance for CO2 hydrogenation to methanol is suboptimal. The catalytic mechanism of Cu species in CZA remains challenging. This study systematically investigates the valence state changes of active Cu species in CZA catalysts and their influence on catalytic performance by modifying catalysts with varying amounts of electron donor K, thereby identifying the catalytic function of Cu species with different valence states. H2-TPR, XPS, and HR-TEM characterizations reveal that highly dispersed K species supported on CZA catalysts inhibit the reduction of CuO, resulting in a small amount of Cu2O active species being produced under reaction conditions, thus causing a decrease in catalytic activity. Furthermore, XRD and Cu LMM spectra show that the proportion of Cu0 in K-modified CZA catalysts increases with K loading, but a higher proportion of Cu0 species on the surface obviously promotes the reverse water gas shift (RWGS) reaction. According to the results of in situ infrared spectroscopy, CZA catalyst follows the reaction pathway mediated by HCOO* in the hydrogenation of CO2 to methanol.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025032504
The environmental persistence and ecotoxicity of diclofenac sodium (DCF), a widely used non-steroidal anti-inflammatory drug, necessitate efficient removal strategies. Covalent organic frameworks (COFs) have emerged as promising adsorbents. Here, a novel nanoribbon COF (COF-TFPPy-DGCl) was synthesized via condensation of 1,3,6,8-tetrakis(4-formylphenyl)pyrene and 1,3-diaminoguanidine hydrochloride. The material was characterized by SEM, TGA, FT-IR, and PXRD. Batch adsorption experiments evaluated the effects of pH, contact time, and initial concentration. COF-TFPPy-DGCl exhibited a maximum adsorption capacity of 370 mg·g−1 for DCF, with capacity decreasing as pH increased. Adsorption kinetics followed a pseudo-second-order model, and equilibrium data fitted the Langmuir isotherm. Selectivity tests demonstrated a DCF removal rate of 96.75%, significantly higher than for ciprofloxacin and bisphenol A (<20%). The adsorbent retained 80% of its capacity after five regeneration cycles, indicating high stability. Mechanistic studies revealed that adsorption is driven by a synergistic combination of electrostatic interactions (dominant), π-π stacking, and hydrogen bonding, facilitated by uniformly distributed active sites. Rapid equilibrium was achieved within 30 minutes. These findings establish COF-TFPPy-DGCl as a highly selective, stable, and regenerable adsorbent for DCF removal from water, offering a theoretical basis for designing advanced COF-based water treatment materials.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026031103
Sintering ash washing wastewater from steel plants is characterized by high salinity, high chloride content, high thallium load, and coexistence of multiple metals, posing significant treatment challenges. This study employed thermodynamic simulation to elucidate the speciation and transformation of thallium in such wastewater, and systematically investigated a combined process of sulfide precipitation coupled with coagulation-flocculation. The results showed that at pH 9–10, thallium predominantly existed as Tl+. Under oxidizing conditions, the stable complex anion [TlCl4]− dominated at pH < 8.1, while at pH > 8.1, a mixed system of solid Tl2O3 and dissolved TlClO3 coexisted. Under optimized conditions (pH 12, 2.0% thallium removal agent, 1.0% multi-effect auxiliary agent), the thallium concentration in the wastewater decreased from an initial 9.58 mg·L−1 to 4.31 μg·L−1, meeting the stringent discharge limit of ≤5 μg·L−1. Concurrent removal of Cu, Zn, and Cd was achieved. The primary removal mechanism was sulfide precipitation, with lattice substitution between Tl+ and K+ serving as an auxiliary pathway. This study provides a practicable technical route for advanced treatment of high-chloride, high-thallium industrial wastewater.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608007
The Minjiang River Basin, subjected to combined pollution from domestic, agricultural, and industrial sources, has become a typical sensitive area for studying the environmental behavior of emerging contaminants such as antibiotics. This study conducted a cross-year comparative analysis of the composition and concentrations of antibiotics in water samples from nine sampling sites during the dry season in November 2022 and 2024. The findings revealed: 1) After the implementation of the "National Action Plan for Reducing Antimicrobial Use in Livestock", the detection concentrations of tetracycline antibiotics (TCs) decreased (e.g., doxycycline concentrations dropped from 7.75 ng/L to undetectable levels), and the mixed risk quotient (MRQ) across the entire basin transitioned from medium to low risk. However, lincomycin (up to 4.6 ng/L), clarithromycin (1.3 ng/L), and florfenicol (0.6 ng/L) have emerged, indicating an increasing hidden ecological risk from substitution. 2) High-concentration antibiotic zones transferred from urban residential areas in 2022 to intensive aquaculture zones and upstream reservoir areas in 2024. The reduction in dry-season water flow intensified pollutant accumulation, synergistically enhancing the effects of tidal drag. Additionally, the conversion of agricultural land to aquaculture ponds led to increased use of alternative drugs (e.g., sulfamethazine), while policy interventions mitigated the exacerbation of urban antibiotic pollution by construction land. This study elucidates the migration patterns of antibiotic pollution under the synergistic effects of policy regulation and natural processes, emphasizing the need to address hidden risks of substitute drugs and the driving role of land-use changes, providing scientific basis for watershed-scale risk assessment and precise management of emerging pollutants.