Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202507043
Municipal sludge with high moisture content and strong viscosity tends to form a dense crust during conventional rotary drum drying, reducing heat and mass transfer efficiency and prolonging drying time. This study proposes a thermal steel ball-enhanced rotary drum drying method that introduces high heat capacity, high thermal conductivity steel balls to achieve synergistic contact heat conduction and mechanical disturbance. An evaluation system incorporating dimensionless moisture ratio (MR), drying rate (DR), characteristic drying time (tdry), effective moisture diffusivity (Deff), and volumetric evaporation intensity (U) was established. Results show that compared with conventional drying, steel ball-enhanced drying increased maximum drying rate (DRmax) by 22.59%–41.19%, U by 38.06%–93.43%, and shortened tdry by 27.56%–48.30%, with more pronounced advantages under high load conditions. Deff was significantly higher throughout the process, with maximum increase up to 48.30%, indicating that ball rolling and collision effectively disrupt the crust and promote moisture migration. Mechanistic analysis reveals that the performance enhancement arises from the dual action of thermal-mechanical coupling and mechanical disturbance, which enhances local heat flux via contact conduction and dynamically renews the drying interface, shortening diffusion paths. This study elucidates the heat and mass transfer mechanisms of thermal steel ball-enhanced sludge drying, providing theoretical support and technical reference for efficient sludge volume reduction and dryer design optimization.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202604013
Reclaimed water serves as an alternative water source for replenishing natural water bodies, yet residual pollutants pose ecological risks. A pilot-scale hybrid vertical flow constructed wetland filled with manganese ore sand, quartz sand, and cobblestones was operated for approximately 140 days to assess nutrient and organic matter removal, ecotoxicity, and the suitability of manganese sand as a functional medium. Influent concentrations were up to 0.4 mg/L ammonia, 0.2 mg/L phosphate, 8 mg/L nitrate, and 30 mg/L COD. After 2–3 months of operation, ammonia and phosphate removal efficiencies exceeded 90% and 80%, respectively. Average reductions for nitrate and COD were 0.67 mg/L and 4.2 mg/L. Manganese sand enhanced organic decomposition, reducing maximum 3D fluorescence intensity by 26%, humic substances by 48%, UV254 by 38%, and achieving 70.8% removal of four target antibiotics. Purified water exhibited no significant genotoxicity, with micronucleus rates approaching tap water levels, and non-concentrated samples showed no acute biotoxicity. However, concentrated samples displayed acute toxicity, suggesting different causative pollutants for genotoxicity and acute toxicity. The study supports manganese sand as an effective medium for improving reclaimed water quality and controlling ecological risks.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3741-3
Functional motifs are essential microscopic units that govern the second harmonic generation (SHG) response in nonlinear optical (NLO) materials. While nonmetal-centered motifs have been extensively studied, metal-centered motifs with outstanding comprehensive performance remain scarce. Here, we report the successful synthesis of the first seven-coordinated indium oxy-chloride and oxy-bromide polyhedra, InO6X (X = Cl, Br), by leveraging the chelating and structure-directing properties of SeO3 groups. The InO6Br polyhedra exhibit the highest polarization anisotropy and hyperpolarizability among all reported indium oxy-chloride and oxy-bromide groups. Consequently, the first non-centrosymmetric halogenated indium selenites, In2(OH)(SeO3)2Cl (ISOC) and In2(OH)(SeO3)2Br (ISOB), were obtained. Both compounds demonstrate strong SHG intensity exceeding six times that of KDP (potassium dihydrogen phosphate) and wide band gaps greater than 4.0 eV, a combination rarely observed in inorganic selenites. This work presents a viable strategy for developing new NLO functional motifs and offers valuable insights for designing novel SHG materials with enhanced performance.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606011
Hexavalent chromium (Cr(VI)) contamination in chromite ore processing residue (COPR) and associated soils poses a persistent environmental challenge. This study developed a dispersedly stabilized iron-sulfur-based slurry (DSS-ISB) modified with an inorganic dispersant to enhance nanoparticle suspension stability and interfacial reactivity. The slurry, with a particle size of approximately 200 nm, efficiently reduced and immobilized Cr(VI) without pH adjustment. Under optimal conditions (liquid-to-solid ratio of 5 mL:10 g, DSS-ISB dosage of 1.8 mg/g, reaction time of 20 h), the removal efficiency exceeded 97%, reducing the leaching concentration from 15.03 mg/L to 0.03 mg/L, well below the GB 5085.3—2007 limit of 5 mg/L. X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analyses revealed a synergistic mechanism of chemical reduction (Fe2+/S2- as dual electron donors) and surface adsorption, converting toxic Cr(VI) to stable Cr(III). Compared with traditional reductants ferrous sulfate (FeSO4) and sodium sulfide (Na2S), DSS-ISB increased removal efficiency by 28.24% and 6.23%, respectively, and unit mass removal capacity by 92.43% and 77.08%. The reagent cost per ton of COPR was reduced to RMB 36.40, achieving savings of 33.82% and 26.02% versus FeSO4 (RMB 55.00) and Na2S (RMB 49.20). The process eliminates pH adjustment and subsequent passivation, simplifying remediation. DSS-ISB offers an economical and green solution for Cr(VI) remediation in both industrial residues and contaminated soils.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3894-9
Photocatalytic production of hydrogen peroxide (H2O2) using water and O2 offers an economical, environmentally friendly, and sustainable route for H2O2 synthesis. However, current photocatalytic systems suffer from poor charge carrier transport, narrow light absorption, and insufficient active sites, leading to unsatisfactory H2O2 production efficiency. In this study, a CoS/ZnIn2S4 (ZIS) composite was constructed by in-situ growing CoS nanoclusters on ZIS via a solvothermal method for photocatalytic H2O2 production. The integration of CoS with ZIS broadened the light absorption spectrum. The optimized CoS/ZIS-3 composite exhibited an exceptional H2O2 production rate of 2693.39 μmol g−1 h−1 under visible light in isopropanol, surpassing pristine ZIS and CoS by factors of 6.54 and 18.08, respectively. The S-scheme heterojunction and built-in electric field synergistically enhanced the separation and transportation of photogenerated charge carriers, thereby improving photocatalytic efficiency. The H2O2 synthesis mechanism involves dual-channel oxygen reduction and water oxidation reactions mediated by CoS/ZIS. The produced H2O2 effectively degraded organic pollutants and inhibited the growth of E. coli. This study presents a promising green strategy for enhancing ZIS-based photocatalysts through constructing S-scheme heterojunctions for efficient H2O2 synthesis.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025032403
An electrochemical sensor for lead ion (Pb2+) detection was developed based on a metal-organic framework (UiO-66-NH2) and conductive polymer polyaniline (PANI) composite. The UiO-66-NH2 was synthesized via hydrothermal method, and the UiO-66-NH2@PANI composite was prepared by in-situ polymerization. The composite was drop-coated onto a glassy carbon electrode (GCE) to fabricate the sensor. Material characterization was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Electrochemical performance was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Key parameters including loading amount, enrichment time, and pH were optimized. Under optimal conditions, the sensor exhibited a linear response to Pb2+ in the concentration range of 10–200 μg·L−1 with a correlation coefficient (R2) of 0.9960, and a limit of detection (LOD) of 9.8 μg·L−1. The sensor demonstrated good anti-interference, repeatability, and stability. Practical applicability was assessed by spiked recovery tests in Yellow River water and tap water, yielding recovery rates of 94.1%–100.8% with relative standard deviations (RSD) ≤3.84%. Comparative analysis with inductively coupled plasma mass spectrometry (ICP-MS) showed comparable accuracy, confirming the sensor's potential for reliable Pb2+ monitoring in environmental samples.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202607004
Pelletizing technology is widely applied in biomass and coal fuel processing, offering advantages in transport, storage, and energy density. Coal gasification fine slag (CGFS), a carbon-rich coal-based solid waste, holds potential as a fuel. This study prepared centimeter-scale composite pellets by blending CGFS with various biomass types under 6 MPa at room temperature for 2 minutes. Combustion and emission characteristics were investigated using a self-developed flat-flame macro-thermogravimetric reactor simulating high heating rate conditions. Results showed that biomass type significantly influenced combustion due to chemical composition differences. Introducing biomass altered fuel particle composition, enhancing combustion rates of single-component fuels by 3–5 times during volatile combustion. Co-combustion reduced NOx and CO emissions by over 50% compared to pure CGFS. Higher biomass ratios accelerated volatile release and shortened burnout time but increased NO emissions due to higher volatile nitrogen content. Conversely, CO emissions decreased due to improved char combustion conditions. These findings provide critical experimental support for optimizing clean and efficient solid fuel production from CGFS and biomass.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202608009
To investigate the flow and heat transfer characteristics of natural draft direct air-cooling towers (NDC) for large coal-fired power generating units, a three-dimensional CFD numerical model covering major plant buildings, air-cooled radiators, and ambient wind fields was established based on the NDC systems of a 2×660 MW unit of a power plant. The influences of meteorological factors, including ambient wind speed, ambient temperature, and ambient wind direction, as well as regulation measures such as rolling shutters, louvers, and bypass windows on the heat dissipation performance of NDC towers were systematically analyzed. The results demonstrate that ambient wind speed acts as the dominant factor governing the performance of the NDC system. As wind speed rose, the uneven distribution of air intake volume and heat dissipation among each cooling delta increased remarkably, which elevated the unit back pressure, and the upstream tower suffered more severe impacts than the downstream one. Ambient temperature exerted a slight effect on circumferential flow distribution, yet substantially changed the overall back pressure of the system. In terms of regulation strategies, closing rolling shutters in the windward zone and reducing the opening of partial louvers can improve air flow redistribution to a certain extent, but will reduce the total air flow rate and total heat dissipation of the entire tower. By contrast, bottom bypass windows can effectively optimize the air intake on the leeward side and boost heat dissipation under high-wind operating conditions, whereas top bypass windows deliver only limited improvement effects. This research can provide fundamental data and technical references for the optimal design, operational regulation, and energy-saving retrofitting of large NDC units.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4129-y
Therapeutic biosynthesis is a promising strategy for precision cancer therapy, yet achieving controlled synthesis of abiotic materials within tumors remains challenging. Here, we report a “dual lock-and-key” system for tumor-specific intracellular synthesis. The precursor, termed “dual-lock,” is activated by two endogenously overexpressed enzymes—azoreductase (AzoR) and nitroreductase (NTR)—acting as “dual keys” in target cancer cells. This activation triggers a condensation reaction that produces fibrous mesh covalent organic polymers (Fm-COPs) in situ. Synthesized Fm-COPs effectively disrupt the cytoskeleton, inhibiting cell migration and invasion while inducing apoptosis. In vivo studies demonstrate that this strategy achieves specific tumor enrichment and deep penetration, leading to significant tumor growth inhibition (tumor inhibition rate >70%) without systemic toxicity, as evidenced by stable body weights and normal histopathology. The dual enzyme-responsive mechanism ensures high selectivity, and the small-molecule precursors facilitate efficient tumor penetration. This work presents a next-generation approach for high-precision cancer therapy, offering a biocompatible and autonomous strategy for intracellular synthesis.