Water scarcity presents a critical challenge to global sustainable development. Membrane distillation (MD) is a promising technology for desalination, yet its performance is often limited to the properties of the hydrophobic membrane. This study reports a facile in-situ reduction strategy to fabricate reduced graphene oxide (RGO)-polyvinylidene fluoride (PVDF) composite membranes for enhanced direct contact MD (DCMD). The composite membranes were designed for robust desalination and potential treatment of hypersaline wastewater. Hydrazine hydrate was employed as the reducing agent within the PVDF casting solution to simultaneously induce phase inversion and the reduction of GO to RGO. The effects of RGO loading on membrane properties were systematically investigated. The optimized membrane (R-4, with a GO precursor concentration of 9 g/L) exhibited a water contact angle of 105.13°, a liquid entry pressure of 2.05 bar, and a high permeate flux of 11.21 kg·m–2·h–1 when treating a 3.5 wt

To achieve low-energy pollutant removal, graphene aerogel (GA) was synthesized via facile water bath-assisted ambient drying, followed by in-situ growth of CuBi2O4 (CBO) onto its surface and into its pores through spraying and hydrothermal treatment, affording an efficient composite aerogel (CBGA-5). Subsequently, comprehensive characterizations confirmed the successful formation of CBGA-5 and revealed a larger specific surface area, improved surface hydrophilicity, and strong light absorption ability that collectively facilitated photogenerated charge carrier separation and transfer. Consequently, the CBGA-5/simulated sunlight (SSL)/persulfate (PDS) system demonstrated exceptional tetracycline degradation under 20 W LED irradiation (1000 W m-2), achieving 93.4% removal efficiency with a rate constant of 0.0425 min-1 under optimized conditions (2.5 mL spray volume, 1.0 g center dot L-1 catalyst, 20 mg center dot L-1 PDS, and 20 mg center dot L-1 tetracycline), representing a 5.05-fold enhancement over the GA/SSL/PDS system (50.5%, 0.00841 min-1). In parallel, mechanistic investigations identified singlet oxygen (1O2) and superoxide radicals (O2-center dot) as dominant reactive species, while Cu+/Cu2+ and Bi3+/Bi5+ redox couples enabled continuous dynamic cycling. Furthermore, CBGA-5 exhibited remarkable stability, retaining 81.1% of its initial activity after five consecutive cycles. Collectively, these findings underscored CBGA-5's potential as a durable, efficient catalyst for solar-driven antibiotic wastewater treatment.

The global freshwater scarcity crisis necessitates the development of efficient desalination technologies. Membrane distillation (MD) is a promising thermal process capable of utilizing low-grade heat and treating highsalinity brines. However, its performance is often limited by the properties of the hydrophobic membrane. This study addresses this challenge by fabricating and optimizing poly (vinylidene fluoride) (PVDF) membranes incorporated with multi-walled carbon nanotubes (MWCNTs) for enhanced MD performance. A series of flatsheet membranes with MWCNTs loadings from 0 to 1.0 wt% were systematically characterized and evaluated in direct contact membrane distillation (DCMD). The results demonstrated that MWCNTs significantly altered the membrane's microstructure, enhancing porosity, optimizing pore size distribution, and improving hydrophobicity and mechanical strength. The membrane with 0.5 wt% MWCNTs (C-3) exhibited an optimal balance of properties, achieving a high DCMD flux of 15.15 +/- 0.15 kg/m2 & sdot;h and a salt rejection 99.99 % using a 3.5 wt% NaCl feed at 60 degrees C. This flux was 61 % higher than that of a commercial PVDF membrane. The enhanced performance is attributed to the MWCNTs acting as nano-reinforcements and structural modifiers. This work provides valuable insights for designing high-performance composite membranes for sustainable desalination.

Urban dust acts as a significant sink for airborne microplastics (MPs), yet residential exposure to MPs in dust remains poorly recognized. Here, dust samples collected across four functional zones (educational, residential, commercial, and park zones) during the winters of 2023 and 2024 were analyzed by optical microscopy and Raman spectroscopy to decipher the spatiotemporal patterns and ecological risks of MPs. MP abundance rose from 568 +/- 84 to 792 +/- 116 items/kg within one year. Polypropylene (PP, 42 %) and polyethylene terephthalate (PET, 31 %) dominated the polymer types. Fibers comprised more than 70 % of the total MPs, with over half of all MPs smaller than 500 mu m. Colored MPs dominated the samples (similar to 70 %), with red being the most prevalent (similar to 33 %). Spatially, residential zones exhibited the highest MP abundance, followed by commercial, educational, and park zones. Significant differences were observed among the four functional zones in MP colour, shape, size and polymer composition. The city-wide Pollution Load Index (PLI) in 2023 and 2024 denotes light pollution, whereas the Potential Ecological Risk Index (PERI) indicates minor risk level in 2023 and high ecological risk in 2024. Notably, residential and commercial zones showed particularly elevated ecological risks. These findings underscore the need for land-use-specific MP monitoring and targeted plastic-waste mitigation strategies in rapidly urbanizing regions.

Although Raman spectroscopy is widely used in microplastic detection, it is highly susceptible to strong fluorescence interference from complex matrices and weathering masking in real aquatic environments. To address this issue, this study proposes a method for identifying microplastics in aquatic environments by combining Raman spectroscopy with machine learning algorithms. In this study, Raman spectra of ten types of microplastic standard samples were systematically collected. After preprocessing and multi-stage data augmentation to expand the dataset, principal component analysis (PCA) was employed to extract key features. During algorithm construction, five-fold cross-validation and multi-seed strategies were introduced to systematically compare the classification performance of four algorithms: support vector machine (SVM), k-nearest neighbors (KNN), multilayer perceptron (MLP), and one-dimensional convolutional neural network (1D-CNN). To validate the generalization ability of the models, real water samples from a wastewater treatment plant and an urban lake were collected to construct an external test set containing five typical polymers: polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS), polyamide (PA), and polyphenylene oxide (PPO). Comprehensive ablation experiments were also conducted. The results showed that the synergistic introduction of PCA and data augmentation effectively bridged the spectral domain transfer gap. On the real water environment test set, all models achieved robust identification mainly for three dominant polymers (PE, PET, PS). SVM demonstrated the most robust balanced recognition, with an average accuracy of 63.45%; 1D-CNN also showed a high recognition potential, averaging 63.08%. This study provides scientific methodological support for monitoring microplastic pollution in aquatic environments.

Iron oxide is one promising catalyst for the removal of volatile organic compounds (VOCs), whereas the unavoidable residue anion in the preparation process will inevitably influence the VOCs oxidation efficiency and the mechanism remains unclear. In this study, Fe2O3 with three typical residual anions (NO3−, SO42− and Cl−) were fabricated by using different iron salts as precursors via hydrothermal method. Systematical evaluation of toluene oxidation performance, in situ DRIFTS, GC–MS analysis and DFT calculations were employed to investigate the anion-mediated influence and mechanism. It was found that all of the Fe2O3-X catalysts followed a MvK-dominated oxidation process, and the type of iron salt precursor significantly influenced the toluene oxidation performance. Fe2O3-N exhibited the best toluene oxidation activity, achieving T90 of 340 °C when treating 1000 ppm toluene at WHSV of 60,000 mL·g−1·h−1. The enhanced lattice oxygen mobility and faster oxygen turnover of Fe2O3-N facilitated toluene deep oxidation. Insufficient toluene oxidation intermediates were accumulated on Fe2O3-S, and Fe2O3-Cl exhibited inferior toluene adsorption and limited active oxygen species participation. These findings provided a feasible strategy for developing VOC oxidation catalysts by adjusting precursor selection.

Chlorinated volatile organic compounds (CVOCs) are highly toxic and recalcitrant pollutants, necessitating the development of efficient catalysts for their deep oxidation. In this work, a series of Pr-doped MnOx catalysts were synthesized and evaluated for the catalytic combustion of chlorobenzene (CB). The optimized MnPr-5% catalyst exhibited superior catalytic performance, achieving 90% CB conversion at a low temperature of T90 = 295 degrees C. Comprehensive characterizations (XRD, Raman, XPS, H2-TPR, and EPR) revealed that the incorporation of Pr species induced significant lattice distortion and electronic modulation. Importantly, the Pr doping facilitated a marked increase in the concentration of surface Mn3 + species and oxygen vacancies by a charge compensation mechanism. The enriched oxygen vacancies served as active sites for the activation of gaseous oxygen into reactive lattice oxygen species, while the high proportion of Mn3+ enhanced the mobility of lattice oxygen, thereby accelerating the Mars-van Krevelen (MvK) redox cycle. Meanwhile, Pr incorporation also improved chlorine resistance by preferentially stabilizing dissociated chlorine species and suppressing the poisoning of Mn active sites. Furthermore, in situ DRIFTS analysis elucidated the reaction pathway and confirmed that the abundant active oxygen species facilitated the rapid deep oxidation of intermediates. This study provides valuable insights into the synergistic regulation of Mn valence states and oxygen defects for the rational design of high-performance catalysts for CVOCs abatement.

To rationally utilize Chinese medicine residue (CMR), biochar was produced through a novel one-step pyrolysis method by CMR doped with iron-rich sludge (IRS) and employed for the removal of tetracycline (TC) in Fentonlike process. The co-pyrolysis biochar (BMS-2) with the weight ratio of IRS to CMR (2:1) achieved the maximum removal efficiency of TC (85.73 %) under the optimum conditions (30 mg/L TC, 10 mM H2O2, pH 7.0, and 0.5 g/ L BMS-2), which was 2.22 times higher than that of CMR biochar. It's probably because that the addition of IRS enhanced the iron content, surface functional groups (C=O), and graphite structures augmented the active sites of BMS-2. Significantly, the catalytic system maintained effective performance across a widened pH range of 3-9. Furthermore, the identification of reactive oxygen species and electron paramagnetic resonance analysis demonstrated that singlet oxygen (1O2) played a predominant role in TC degradation, whereas hydroxyl radicals (& sdot;OH) and superoxide radicals (O2-& sdot;) had a secondary impact. This work advanced dual waste valorization by transforming industrial and medical waste into functional catalysts, established pH-neutral Fenton-like systems overcoming acidic limitations, and elucidated 1O2-mediated mechanisms for the removal of antibiotic wastewater.

Tetracycline (TC) is a prominent antibiotic that remains largely unmetabolized in humans and animals, resulting in significant excretion into the environment. This poses a substantial threat to human health, highlighting the urgent necessity for effective removal of TC from water sources. A series of catalytic materials were prepared by subjecting natural psilomelane (NP) to roasting at varying temperatures and subsequently employed to activate persulfate for the degradation of tetracycline. The natural psilomelane roasted at 500 °C (NP‐500) exhibited the excellent catalytic activity compared to the unroasted natural psilomelane. The removal rate of tetracycline at a concentration of 30 mg/L was 84.6% when a dosage of 0.5 g/L of catalyst and 0.5g/L of PMS was employed. Furthermore, an appropriate calcination temperature could facilitate the generation of oxygen vacancies and active metal ions (Fe, Mn), which were crucial for the formation of active oxygen. Besides, superoxide radicals (O 2 • − ) and singlet oxygen ( 1 O 2 ) were the primary reactive species. And the initial pH and co‐existing anion experiments showed that the NP‐500/PMS system presented a wide range of potential applications. Finally, based on the LC‐MS and experimental results, a possible degradation pathway and mechanistic map of TC were proposed.

In recent years, microplastics, as emerging contaminants, have raised global concern among scholars due to their potential threats to both ecological systems and human health. Traditional water treatment methods primarily remove microplastics through phase transfer mechanisms, which fail to achieve actual degradation. In contrast, Advanced Oxidation Processes (AOPs) demonstrate superior efficacy by generating reactive free radicals that degrade microplastics efficiently. Remarkably, AOPs can even mineralize microplastics into harmless CO₂ and water, positioning them as a forefront research focus for microplastic remediation. This paper systematically reviews applications of various AOPs, including UV/UV-H₂O₂ oxidation, O₃/O₃-H₂O₂ oxidation, UV-induced photocatalysis, solar/visible light-induced photocatalysis, electrochemical oxidation, and persulfate oxidation, in degrading aqueous microplastics. The degradation efficiencies, mechanistic pathways, and reaction kinetics are critically analyzed, alongside a comparative assessment of each technique's advantages and limitations. Finally, the review discusses future prospects and challenges for implementing AOPs in microplastic treatment.

The current researches on microplastics in different water layers of reservoirs remains limited. This study aims to investigate the microplastics in different water layers within a source water reservoir. Results revealed that the abundance of microplastics ranged from 2.07 n/L to 14.28 n/L (reservoir, water) and 3 to 7.02 n/L (river, water), while varied from 350 to 714 n/kg(dw) (reservoir, sediment) and 299 to 1360 n/kg(dw) (river, sediment). The average abundance in surface, middle, and bottom water were 6.83 n/L, 6.30 n/L, and 6.91 n/L respectively. Transparent fibrous smaller than < 0.5 mm were identified as the predominant fraction with Polypropylene and Polyethylene being the prevalent polymer types. Additionally, the pollution load index, hazard index, and pollution risk index were calculated for different layers and sediments. Results showed that surface water exhibited a moderate level of risk while the sediments posed a low level of risk. Both the middle and bottom water showed elevated levels of risk due to higher concentrations of polymers with significant toxicity indices. This study presents novel findings on the distribution of microplastics in different water layers, providing crucial data support for understanding the migration patterns of microplastics in source water reservoirs and facilitating pollution prevention efforts.

This study examined the removal efficiency of microplastics (MPs) in a wastewater treatment plant (WWTP) in Zhengzhou, China. A three-point sampling approach (influent, process effluent, and final effluent) was employed, with samples collected across three seasons (summer, winter, and autumn) to investigate seasonal variations in MPs. The abundance of MPs in influent ranged from 184.3 ± 4.0 to 145.3 ± 24.0 n/L, while in the process effluent it decreased to 79.3 ± 18.7 to 62.3 ± 15.0 n/L. Furthermore, in final effluent it was further reduced to 26.0 ± 7.0 to 38.7 ± 5.1 n/L. Fragments and granule-shaped MPs predominated (>80%), with polypropylene (PP, 42.6%) and polyethylene terephthalate (PET, 31.8%) emerging as the dominant polymer types. The removal efficiency of MPs in the WWTP was 86%, 81%, and 73% in summer, autumn, and winter, respectively. Additionally, the plant exhibited differing removal efficiencies for MPs of varying sizes. Notably, residual sludge retained substantial MPs loads, with seasonal abundances measuring 22.3 ± 3.2, 14.2 ± 2.4, and 29.1 ± 6.7 n/g in summer, autumn, and winter samples, respectively. The findings underscore the importance of implementing effective management strategies and interventions in wastewater systems to mitigate MP pollution.

Microplastics have been widely detected in wastewater treatment plants, but there is still a significant dearth of research data on the removal efficiency of microplastics in such plants. The present study focused on three wastewater treatment plants situated in Zhengzhou, China. On-site sampling and Raman spectrum detection techniques were employed to identify microplastics in both wastewater and sludge samples, while the removal efficiency of microplastics was quantified for each plant. Results showed that the abundance of microplastics in influent exhibited ranging from 147.5 ± 2.6 to 288.8 ± 11.8 n/L, while the range in sludge samples was from 12,024.7 ± 1737.0 n/kgdw to 20,818.4 ± 5662.0 n/kgdw. The removal efficiencies of microplastics in the three WWTPs ranged from 76.2% to 91.2%. The primary components of microplastics were generally identified as fibers ranging in size from 10 to 100 μm. The samples collectively exhibited a total of seven distinct colors, with the predominant proportion being transparent. Polypropylene was the polymer type with the highest proportion. The sludge in WWTPs plays a pivotal role in the accumulation of MPs from wastewater bodies, necessitating increased attention toward its proper disposal in future endeavors.

As an emerging contaminant, the spatial distribution characteristics of microplastics in source water reservoirs warrant further attention from researchers. In this study, the Luhun Reservoir, which is situated in the middle reaches of the Yellow River, was selected as the object. Field sampling and detection were conducted to ascertain the presence of microplastics in water and sediment. The results indicated that the abundance of microplastics in the water varied from 1.60 to 13.26 items/L, while in the sediment it ranged from 792.38 to 2352.00 items/kg. Polyethylene, polyethylene terephthalate, and polyamides exhibited higher levels in the water, whereas polyamides and polyethylene were more predominant in the sediments. Additionally, the surface layer exhibited the highest abundance of microplastics, followed by the bottom, while the intermediate layer displayed the lowest. As the depth increased, there was a gradual decrease in the proportion of polyethylene and an increase in the proportions of polyethylene terephthalate and polyamides. The risk assessment results showed that the Pollution Risk Index value of the water was 201.79, while the sediment had a value of 184.98, indicating a moderate potential ecological risk. This study provides valuable insights into the spatial distribution patterns of microplastics at different water depths and provides crucial data support for understanding the migration patterns of microplastics in source water reservoirs.

As an emerging contaminant, microplastics (MPs) have caused global environmental pollution and become the focus of current research. This research presents a comprehensive literature review on the occurrence and distribution characteristics of MPs in surface water within China. The findings demonstrate that stainless steel barrels currently serve as the predominant tool for water sampling, whereas Fourier Transform Infrared spectrometer and Raman spectrometer are extensively employed for the detection of MPs. The mean abundance of MPs in rivers ranges from 0.57 to 930.00 n/L, while in lakes and reservoirs, it varies between 1.30 and 27.50 n/L. The size of MPs in surface waters is mainly less than 1 mm, with the transparent or white fibrous forms being the most frequently observed morphology, and polypropylene and polyethylene emerge as the primary polymer types. Additionally, the investigation of MPs in lakes and reservoirs in Northeast China and South China remains unexplored. Currently, an increasing number of Chinese cities are opting for surface water as their water source, so more studies should focus on enhancing the accumulation of research data on MPs in surface water to provide substantial support for the development of pollution control measures in the future.

As an emerging contaminant, the presence of microplastics is widespread in the environment. However, current research regarding the removal of microplastics by drinking water treatment plants (DWTPs) remains insufficient. This study aims to investigate microplastics in water and sludge in four DWTPs in Zhengzhou; these DWTPs have different water sources. The results revealed that the abundance of microplastics in raw water ranged from 12.80 ± 0.80 to 25.07 ± 1.67 n/L. Overall, fibers and fragments ranging from 10 to 100 μm constituted the primary components. The proportion of white and transparent microplastics was the highest. Among the ten polymer types detected, polyvinyl chloride, polyphenylene oxide, and polyethylene terephthalate were the predominant ones in raw water; polyethylene terephthalate emerged as the prevalent polymer type in treated drinking water, with both polyethylene terephthalate and polyvinyl chloride being primarily present in sludge. The removal rate of microplastics ranged from 45.8% to 74.5%. Furthermore, the removal rates at the sedimentation tank outlet accounted for more than 50.0% of the total removal rate. The abundance of microplastics in sludge was significantly higher than that in water, indicating a concentrated environment for the persistence of microplastics. The proper disposal of sludge has emerged as one of the challenges requiring our attention.

With the rapid development of industry, large amount of refractory organic pollutants in domestic and industrial wastewater are discharged into water bodies, posing a serious threat to human health and the environment. Advanced oxidation processes (AOPs) based on persulfates have shown outstanding performance in treating refractory organic wastewater, and the use of single-atom catalysts (SACs) can maximize the utilization of metal atoms and reduce the leaching of metal ions, which has a promising application prospect in the activation of persulfates for the degradation of organic pollutants. The preparation methods of single-atom catalysts were summarized, and the advantages and disadvantages of various methods were discussed. The application of single-atom catalysts with metals such as Fe, Co, Mn and Cu in the activation of persulfates for the degradation of organic pollutants was discussed. The mechanisms of single-atom catalysts in activating persulfates and the degradation mechanisms of the persulfate system catalyzed by single-atom catalysts towards organic pollutants were summarized. Finally, the future development of single-atom catalysts in activating persulfates for the degradation of organic pollutants was discussed.

An amorphous copper silicate catalyst was prepared using Cu(NO3)2 and Na2SiO3 & BULL;9H2O as precur-sors. Characterization of amorphous copper silicate was accomplished by several techniques, includ-ing X-ray diffraction, X-ray photoelectron spectroscopy analysis, scanning electron microscopy, transmission electron microscopy, thermogravimetry-differential thermal curves, Fourier-transform infrared spectroscopy, and nitrogen adsorption-desorption. The results of characterization showed that Cu-Si binary oxide and CuO were formed on the surface of amorphous copper silicate and contained abundant functional groups. The dosages of the catalyst, ozone, and humic acid affected the removal efficiency of p-chloronitrobenzene (p-CNB). A hydroxyl radical (& BULL;OH) scavenger exper-iment, electron spin resonance (ESR) analysis, and pH experiment demonstrated that & BULL;OH was the predominant reactive specie for p-CNB degradation. Catalytic reusability studies demonstrated that amorphous copper silicate maintained its catalytic activity and stability for five consecutive cycles.

根据河南省三门峡市沿黄文化博物馆的实际设计过程,介绍沿黄文化博物馆消防系统设计的主要组成部分,分析各部分消防系统的设计要点、参数选用和系统控制等内容.消防系统设计过程中采用了多种自动灭火系统,并比较了博物馆展厅中常用的自动灭火系统.该博物馆为多层公共建筑,研究可以为此类公共建筑的消防设计提供借鉴和参考.