Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025021005
Microplastic pollution in freshwater environments has escalated, leading to increased accumulation in wild fish. This study investigated the occurrence characteristics of microplastics (MPs) in the gills, gastrointestinal tract (GIT), and muscle of four wild fish species with different feeding habits from Baiyangdian Lake, China. MPs were detected in all tissues. The average abundance was highest in the GIT (11.63 ± 10.76 items/individual), followed by gills (7.44 ± 6.79 items/individual), and lowest in muscle (3.91 ± 3.16 items/individual). The majority of MPs were transparent and black fibers smaller than 0.5 mm. Polymer analysis identified polypropylene (PP) and polyethylene (PE) as dominant components. Significant differences in MP abundance were observed among species, with carnivorous and herbivorous fish (e.g., snakehead and grass carp) showing higher total MPs than omnivorous and planktivorous fish (e.g., mosquitofish and topmouth gudgeon). However, when normalized by body weight, smaller fish exhibited higher MP concentrations in the GIT, suggesting a greater risk per unit mass. This study provides baseline data on tissue-specific MP distribution in wild freshwater fish with varying feeding behaviors and habitats, highlighting the influence of trophic level and body size on MP accumulation.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026012804
This study conducted online monitoring of volatile organic compounds (VOCs) at a roadside site on a main arterial road in Haikou, a tropical city, during summer 2023 (June 25–September 30). A total of 56 VOCs were measured. The mean total VOC concentration (φ(TVOCs)) was (9.05 ± 6.24) nmol·mol−1, with concentrations in the order: alkanes > alkenes > aromatic hydrocarbons > alkynes, dominated by light alkanes. Alkenes and aromatic hydrocarbons contributed significantly to atmospheric chemical reactivity, while secondary organic aerosol formation potential (SOAFP) was limited, influenced by both VOC concentrations and temperature. VOC concentrations exhibited a pronounced bimodal diurnal pattern, consistent with traffic peaks. Ratio analysis indicated a Toluene/Benzene (T/B) ratio slightly higher than typical vehicle exhaust values, and an iso-Pentane/n-Pentane (i/n) ratio suggesting fuel evaporation influence. Positive Matrix Factorization (PMF) identified four sources: gasoline/LPG vehicle exhaust (49.9%), solvent use or vehicle evaporation (26.1%), diesel vehicle exhaust (14.9%), and biogenic sources (9.1%). SOAFP was mainly contributed by solvent use/evaporation (35.7%), gasoline/LPG exhaust (34.6%), diesel exhaust (22.0%), and biogenic sources (7.7%). These findings indicate that under tropical summer high-temperature conditions, roadside VOC pollution is predominantly traffic-related, with vehicle evaporation sources non-negligible, providing insights for evaluating vehicular impacts on particulate pollution.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3886-1
Organic-inorganic hybrid Mn(II) halides have attracted considerable attention for optoelectronic applications due to their environmental friendliness and high photoluminescence quantum yield (PLQY) originating from the d-d transition (4T1(G) → 6A1) of Mn2+. However, complex synthesis processes restrict their potential for low-cost, large-scale production. In this study, the Mn(II) halide (C22H22O2P)2MnBr4 was synthesized via a simple and efficient mechanochemical ball-milling approach, achieving high photoluminescence efficiency and production yield. The halide exhibits intense green emission centered at 520 nm with a PLQY of up to 96.1%. Combined experimental and theoretical characterizations confirm that the strong light emission originates from the synergistic interaction between organic cations and inorganic framework components. A white light-emitting diode (WLED) device based on (C22H22O2P)2MnBr4 was fabricated, exhibiting bright white light emission and a wide color gamut of 113% NTSC. Furthermore, a scintillation screen based on (C22H22O2P)2MnBr4 was fabricated and utilized to investigate internal structures of various objects. The screen demonstrates a high relative light yield of 70546 photons MeV−1, a low detection limit of 33.8 nGy air s−1, and a spatial resolution of up to 12.36 lp mm−1. Finally, by integrating the scintillation screen with a thin-film transistor (TFT) backplane, the resulting X-ray detector successfully enables simulated medical imaging of dental caries. This work establishes a robust foundation for large-scale synthesis of highly efficient luminescent Mn(II) halides and highlights their potential in multifunctional light-emitting applications.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(25)60628-1
The coupling of CO2 with olefins to produce cyclic carbonates has emerged as an important research topic in sustainable chemistry, owing to its high atom economy and the wide applicability of the resulting products. However, this reaction faces a significant challenge due to the mismatch between the rates of the epoxidation and cycloaddition steps. In this work, a series of TS-1 zeolite catalysts encapsulating different amounts of molybdenum acetylacetonate were prepared through hydrothermal synthesis followed by post-treatment, with the aim of elucidating the rate balance between the epoxidation and cycloaddition steps and the underlying regulation mechanism. Characterization results show that the Mo species were present as highly dispersed molybdenum acetylacetonate complexes that were stably confined within the TS-1 framework. These complexes interact electronically with the tetra-coordinated Ti sites to form synergistic active centers, while imposing negligible effects on the zeolite structure and porosity. In the CO2-styrene coupling reaction, tuning the Mo loading enabled effective control over the epoxidation rate, thereby achieving an appropriate balance with the subsequent cycloaddition step. The optimized catalyst delivered excellent performance under mild conditions, with a styrene conversion of 83.4% and a selectivity of 75.3%, and also exhibited outstanding recyclability. Overall, this encapsulated catalyst successfully addresses the dual challenges of rate matching and active-site stability in CO2–olefin coupling, providing valuable insights for the rational design of efficient, durable bifunctional catalysts.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.3724/2097-213X.2025.JFCT.0034
Catalytic cracking of gasoline and diesel to light olefins is a pivotal route for high-value utilization of surplus fuels, typically employing zeolite catalysts. This study systematically investigates the effects of zeolite type and acidic properties on the catalytic cracking of dodecane, a diesel model compound, using SAPO-34, ZSM-5 with SiO2/Al2O3 ratios of 38, 85, and 200, and USY. Catalysts were characterized by XRD, SEM, N2 physisorption, NH3-TPD, and pyridine-FTIR, and evaluated in a fixed-bed reactor. Results demonstrate that zeolite type is the primary determinant of conversion and product distribution. SAPO-34, with 0.38 nm pores, achieved only 24.33% conversion and negligible BTX yield, with severe external coking. ZSM-5-38 and USY, with larger pores, achieved near-complete conversion; however, ZSM-5-38, possessing moderate acidity, yielded the highest light olefins (18.40%) and minimal coke (0.18%), while USY, with higher acidity, promoted hydrogen transfer and coking (12.90% coke). Within ZSM-5 series, lower acid site density (ZSM-5-200) proved optimal, achieving 97.79% conversion and a total light olefin yield of 41.93% (ethylene 11.11%, propylene 20.33%, butenes 10.49%) with low coke (0.43%). The study proposes reaction pathways and regulatory mechanisms, highlighting that zeolite type and acidity govern the relative rates of cracking, hydrogen transfer, oligomerization, aromatization, and coking, thereby dictating performance. These findings provide a rational basis for optimizing zeolite catalysts in commercial gasoline/diesel cracking processes.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202511027
Aquaponics systems integrate aquaculture and hydroponics to recycle resources, yet nutrient recovery from aquaculture sludge remains inefficient. This study investigated anaerobic acidification as an alternative to conventional anaerobic digestion, which suffers from long conversion cycles. Batch experiments compared two sludge loading rates: high (13.22 kg·kg−1) and low (4.61 kg·kg−1) (mass of sludge per mass of anaerobic inoculum). Under low loading, soluble chemical oxygen demand (SCOD) exhibited a single peak, reaching a maximum organic solid conversion of 68.2% at 70.5 h. In contrast, high loading produced three SCOD peaks with an average peak conversion efficiency of only 26.9% at 27.5 h and higher residual concentrations. Ammonia nitrogen conversion was slightly higher under low loading (64.8%) than high loading (62.2%), while orthophosphate conversion was markedly superior (95.7% vs. 76.4%). The optimal hydraulic retention time for low-loading operation was 144 h, corresponding to an organic loading rate of 0.77 kg·(kg·d)−1. Under these conditions, the produced ammonia and phosphate can be effectively recovered without adversely affecting water quality, as the biofilter converts ammonia to nitrate for plant uptake. Microbial analysis revealed that low-loading conditions favored the dominance of Acinetobacter (relative abundance 66.6%), which likely enhances organic degradation and nutrient release. These findings demonstrate that anaerobic acidification under low loading is a promising strategy for efficient nutrient recovery in aquaponics, offering a shorter conversion time and higher nutrient yields than traditional methods.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026051001
Haikou, a representative tropical city in China, experiences air pollution influenced by both local emissions and regional transport. This study analyzed O3 and PM2.5 concentrations, emission sources, and meteorological fields from Haikou and Guangdong-Guangxi cities in 2024, employing correlation analysis and the Weighted Potential Source Contribution Function (WPSCF) to systematically investigate spatial-temporal patterns, regional linkages, and transport mechanisms. Results revealed distinct pollution characteristics: Hainan exhibited prominent O3 pollution in autumn and winter, while the Pearl River Delta (PRD) in Guangdong suffered significant O3 pollution year-round, positioning it as the core control area. Guangxi was characterized by severe PM2.5 pollution in winter with extensive high concentration areas. Haikou's O3 and PM2.5 concentrations showed strong correlations with those in Zhanjiang and Maoming throughout the year, particularly in winter. Regional transport analysis indicated that O3 pollution in Haikou depended on stable cross-regional precursor transport coupled with intense photochemical conditions, whereas PM2.5 exhibited diverse transport pathways across seasons. Lag effect analysis confirmed that pollution exceedance days were substantially influenced by upwind transport from the previous day, highlighting the dominant role of cross-regional physical transport. Autumn pollution was driven by stable surface northeasterly winds and upper-level uniform pressure fields. Potential source areas were highly consistent with the MEIC emission inventory, confirming distinct contributions of transport pathways for O3 and PM2.5. These findings provide a scientific basis for differentiated collaborative control of air pollution in tropical coastal cities.
Journal of Fuel Chemistry and Technology•2026•DOI: 10.1016/S1872-5813(26)60667-6
The introduction of an appropriate amount of Cu effectively enhances the catalytic performance of ZnO-ZrO2 solid solution catalysts in CO2 hydrogenation to methanol. However, systematic studies on the effect of Cu content in ZnO-ZrO2 solid solution catalysts remain limited. In this work, a ZnO-ZrO2 solid solution and a series of Cu/ZnO/ZrO2-x catalysts (x = 0.3, 0.7 and 0.9, denoting the molar ratio of Cu/(Cu+Zn+Zr)) were prepared by co-precipitation method. Among these catalysts, the Cu/ZnO/ZrO2-0.7 catalyst exhibited the optimal catalytic performance, with a space-time yield of methanol (162.7 g/(kg·h)) that was 6.6 times higher than that of the ZnO-ZrO2 solid solution catalyst (24.8 g/(kg·h)) at 250 °C. Structural characterizations reveal that the introduction of an appropriate amount of Cu led to the coexistence of a solid solution and individual metal oxides, and promoted the formation of medium-strength basic sites. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results further confirm that Cu introduction facilitated the conversion of key reaction intermediates. This work provides a systematic investigation of the influence of Cu content on the methanol synthesis performance of ZnO-ZrO2 solid solution catalysts and elucidates the promotional mechanism induced by Cu incorporation.