Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024100805
A fluorescent metal-organic framework (MOF), PCN-128, was synthesized via a solvothermal method using zirconium tetrachloride (ZrCl4) as the metal source and tetrakis[4-(4'-carboxyphenyl)phenyl]ethylene (H4ETTC) as the organic linker. The resulting material exhibited regular morphology, high crystallinity, strong luminescence, and good stability. PCN-128 was employed as a fluorescent probe for the trace detection of malachite green (MG), a banned veterinary drug, in aquaculture water and freshwater fish tissue. The probe demonstrated exceptional selectivity toward MG among 13 veterinary drugs and robust anti-interference performance against 16 anions, 16 cations, and 12 additional veterinary drugs. The method achieved a broad linear detection range from 0.0 to 7.0 μmol·L−1 with a limit of detection (LOD) of 2.73 nmol·L−1. Spike-and-recovery experiments in three aquaculture water samples and one freshwater fish sample yielded recoveries between 89.80% and 113.7%, with relative standard deviations (RSD) not exceeding 2.59%. These results confirm that the developed method is accurate, reliable, and suitable for routine monitoring of MG residues in aquaculture water and aquatic products, addressing a critical gap in food safety surveillance.
The Chinese Journal of Process Engineering•2026•DOI: 10.12034/j.issn.1009-606X.225185
Sulfur hexafluoride (SF6), widely used as an insulating gas in high-voltage electrical equipment, possesses a global warming potential (GWP) 25,200 times that of CO2, necessitating efficient degradation technologies. This study employed computational fluid dynamics (CFD) to simulate the thermal catalytic degradation of SF6 in a fixed-bed reactor, integrating models for porous media, heat transfer, turbulence, and chemical kinetics. The simulations revealed significant radial non-uniformities in pressure, velocity, temperature, and species concentration distributions, with temperature identified as the dominant factor influencing degradation efficiency. Radial temperature gradients caused uneven reaction rates, with degradation rates near the wall substantially exceeding those at the central axis, thereby reducing overall SF6 conversion. To address this, structural optimizations were implemented, including reducing the reactor tube diameter and incorporating inert porous media with high thermal conductivity at both ends of the catalytic section. These modifications enhanced radial heat transfer, homogenized the temperature field, and improved the uniformity of reaction rates and species concentrations. Parametric studies on inlet gas velocity showed that both excessively low and high flow rates were detrimental: low velocities led to underutilization of the downstream catalyst and increased energy consumption, while high velocities deteriorated heat transfer and exacerbated radial temperature gradients. The optimal inlet velocity range was determined to be 0.4–0.8 m/s for a reactor tube inner diameter of 10 mm, balancing catalyst utilization, energy consumption, and degradation efficiency. This research provides data-driven guidance for the design and scale-up of SF6 catalytic degradation reactors.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025010701
This study investigated the long-term effects of biochar application on physicochemical properties and microplastic accumulation in aeolian sandy soils, based on a field experiment established in 2014. After seven years of mulched cultivation, soil samples were collected from 0–30 cm and 30–60 cm depths. Biochar application significantly increased soil porosity and available nitrogen, phosphorus, and potassium contents, while reducing bulk density. At a biochar rate of 126.00 t·hm−2, soil water content was significantly reduced. Microplastic abundance averaged 3459.57 pieces·kg−1 in the 0–30 cm layer, with the highest abundance at 126.00 t·hm−2; in the 30–60 cm layer, average abundance was 3163.50 pieces·kg−1, with the highest at 63.00 t·hm−2. Microplastics were predominantly transparent, film-shaped, and 0–0.5 mm in size. The results indicate that biochar application significantly increased microplastic abundance in aeolian sandy soils, providing insights into microplastic adsorption and enrichment in agricultural ecosystems. Further research is needed to elucidate underlying mechanisms.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606005
In the context of carbon peaking and carbon neutrality, urban reclaimed water plants must adopt measures such as energy conservation, consumption reduction, and enhanced resource and energy utilization to achieve carbon neutrality. This study developed a carbon emission balance model and accounting method for such plants, incorporating strategies of carbon emission reduction, carbon substitution, and carbon sink. The optimal pathway towards carbon neutrality was evaluated based on the carbon emission balance ratio. Using a 1×10⁵ m³/d urban reclaimed water plant as a case study, the results showed total carbon emissions of 20,934 t CO2e. The carbon emission reduction from reclaimed water source heat pumps for heating and cooling was 21,701 t CO2e, yielding a carbon emission balance ratio of 103.7%. In contrast, other carbon reduction measures contributed 15,424 t CO2e, with a balance ratio of 73.7%, highlighting the pivotal role of reclaimed water source heat pumps. When the heat pump extracted 27% and 36% of residual thermal energy, coupled with reclaimed water reuse or sludge anaerobic digestion-cogeneration, respectively, both pathways achieved a 100% balance ratio. Assuming year-round extraction, the balance ratio reached 213%. The carbon reduction ratio between utilizing residual thermal energy and chemical energy was 8.76:1. This study demonstrates that urban reclaimed water plants can achieve carbon neutrality through multiple pathways, with residual thermal energy recovery exhibiting significant potential.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202508006
Landfill leachate, characterized by high ammonia nitrogen, high organic load, complex toxic components, and low nitrogen removal efficiency, poses significant environmental challenges. To achieve efficient nitrogen removal, a continuous-flow two-stage anoxic/oxic (A/O) moving-bed biofilm reactor (MBBR) system coupled with anaerobic ammonium oxidation (Anammox) was constructed and operated for long-term treatment of actual landfill leachate. After biofilm attachment and multi-gradient acclimation, influent concentrations were gradually increased from low levels (NH4+-N ~200 mg·L−1, COD ~2500–3000 mg·L−1) to high levels (NH4+-N ~1800 mg·L−1, COD ~8500 mg·L−1). During stable operation, average removal efficiencies of NH4+-N and COD reached 97.7% and 66.8%, respectively, with total nitrogen (TN) removal efficiency improving to 93.9%. Along the reactor, the first A/O stage achieved major organic degradation and ammonia oxidation, while the second stage facilitated nitrite accumulation and promoted Anammox for synergistic nitrogen removal. High-throughput sequencing revealed Proteobacteria as the dominant phylum (>50%), with denitrifying genera such as Azoarcus and Thauera significantly enriched. Planctomycetota abundance increased from 0.6% to 3.7%, and Candidatus Kuenenia was detected, confirming successful Anammox colonization and participation in nitrogen removal. This study validates the efficient combined nitrogen removal mechanism of the A/O–MBBR system with Anammox, providing theoretical basis and technical support for engineering treatment of high-ammonia wastewater.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4017-y
Lattice distortion via entropy engineering can significantly optimize thermoelectric performance by intensifying phonon scattering. However, excessive lattice distortion in high-entropy materials inevitably hinders carrier transport, limiting the wide-temperature average ZT (ZTave). To enhance the wide-temperature thermoelectric performance of low-cost PbS-based compounds, this work introduces moderate lattice distortion by controlling entropy around 1.0R (R is the gas constant) to balance phonon and carrier transport, alleviating restrictions on carrier mobility. Substantial Se and Te alloying in PbS induces rock-salt lattice distortion, effectively impeding phonon propagation, thus suppressing lattice thermal conductivity (κlat) from 2.41 W m−1 K−1 in PbS to 0.66 W m−1 K−1 in PbS0.5Se0.35Te0.15 at 300 K. Additionally, Cu interstitials are introduced into the lattice-distorted PbS0.5Se0.35Te0.15 to further optimize carrier density and weighted carrier mobility (μW), leading to significant improvement in μW/κlat parameter at 300–773 K. Finally, a room-temperature ZT of 0.53 and a maximum ZT of 1.44 are obtained in PbS0.5Se0.35Te0.15-1%Cu sample, contributing to an impressive ZTave of 1.08 at 300–773 K and a maximum power generation efficiency (ηmax) of 7.5%. The results outperform previously reported cost-effective PbS-based compounds and highlight the importance of lattice distortion regulation in enhancing wide-temperature thermoelectric performance.