Abstract We examined the growth tolerance, bioremoval efficacy, and metabolomic profiles of the cellular responses of Chlorella pyrenoidosa to phenol and 4-fluorophenol. We found that C. pyrenoidosa can tolerate exposure to 100 mg/L of phenol and 4-fluorophenol, and the growth of algal cells had a significant hormesis of inhibition first and then promotion. Up to 70% bioremoval of phenol and 4-fluorophenol may occur after 240 h of treatment. Superoxide dismutase (SOD) and CAT activities, malondialdehyde (MDA) content, and reactive oxygen species (ROS) in algal cells in the phenol- and 4-fluorophenol-treated groups were similar or lower than in the control group. Furthermore, photosynthetic pigment and glycerophospholipid contents were significantly upregulated in both phenol- and 4-fluorophenol-treated groups, as indicated by the metabolomic analysis of C. pyrenoidosa, resulting in the vigorous growth of algal cells compared to the control group. Therefore, C. pyrenoidosa can be an excellent biosorbent for phenol and 4-fluorophenol.

Abstract The amount of particles and organic matter in wash-waters and effluent from the processing of fruits and vegetables determines whether they need to be treated to fulfil regulatory standards for their intended use. This research proposes a novel technique in photovoltaic cell-based renewable energy in saline water analysis using the oxidation process and deep learning techniques. Here, the saline water oxidation is carried out based on photovoltaic cell-based renewable and saline water analysis is carried out using Markov fuzzy-based Q-radial function neural networks (MFQRFNN). The plan is entirely web-oriented to enable better control and effective monitoring of water consumption. This monitoring makes use of a communication system that collects data in the form of irregularly spaced time series. Experimental analysis has been carried out based on water salinity data in terms of accuracy, precision, recall, specificity, computational cost, and kappa coefficient.

Abstract Zinc is one of the heavy metals present in textile wastewater with high concentrations. However, the chronic toxic effects of zinc on aquatic vertebrates are still ambiguous. Zinc accumulation in zebrafish after chronic zinc exposure and toxic effects on the intestines, muscles, and gills were investigated in this study. The results showed that a significant accumulation of zinc in the intestine, muscle, and gill was observed after 25 d of zinc exposure. The toxic effects of zinc were mainly in the form of zinc-induced oxidative stress in zebrafish, potential neurotoxicity, and changes in intestinal microbes. Significant changes in the levels of superoxide dismutase, catalase, metallothionein, glutathione, and malondialdehyde indicated that zinc damaged the antioxidant system of adult zebrafish. Zinc exposure resulted in a significant decrease in acetylcholinesterase activity and abnormal neural signaling. Furthermore, zinc exposure resulted in increased intestinal microbial richness and decreased the Simpson index in adult zebrafish. At the phylum and genus levels, the predominant microbes in the intestine are altered by zinc. In summary, this study provides an analysis of the toxic effects of chronic zinc exposure on adult zebrafish and the potential mechanisms, which are important for assessing the dual effects of zinc on aquatic organisms.

Abstract In this work, Phragmites australis and Vallisneria natans were selected as the research objects and were cultured for 10 d under 0.10 μg L−1 sulfadiazine (SD) stress in a simulated surface flow wetland reactor. SD degradation was conducted at pH = 7 and 25 °C for 96 h. Each plant group conformed to the first-order kinetic model of degradation, and the degradation rate increased with time, reaching the maximum at 96 h. At 96 h, the degradation rate of P. australis communities was higher than that of V. natans. SD metabolites showed that the degradation pathways in the plant rhizosphere were mainly hydroxylation, aminolation, and S–N bond cleavage. In the analysis of rhizosphere bacterial community structure, the bacterial phyla that could degrade antibiotics accounted for a large proportion. Compared with before degradation, the dominant phylum and genus did not change after degradation (96 h), but their abundance changed to varying degrees, and new genera appeared in the P. australis group. This research provides a reference for the degradation of antibiotics in karst areas and new information on the mechanism of SA degradation in the plant rhizosphere.

Abstract Over the past 30 years, water security issue in Chinese cities has become increasingly serious, largely due to rapid urbanization, population growth and disproportionate investment in water infrastructure. Urban rainwater harvesting (URWH), a household and community-level rainwater management measure, has been widely used during this period. This study provides a critical review of the policies, methods, technology, construction, implementation and benefits related to URWH in China. We show that URWH in China has gone through three phases over the past 30 years: an initial development phase, a rapid development phase and a sponge city construction phase. URWH research has focused mainly on rainwater harvesting, storage, utilization, management and other technologies, with limited attention to policy and benefit analysis. However, the scale of URWH construction and implementation in China remains small and needs further development. Currently, while URWH assessments cover social, ecological and environmental benefits, the economic benefits need to be further strengthened. The next step in URWH implementation should be to strengthen research and development of policy, legal and design standards. This study provides guidance for the implementation of URWH in Chinese cities and other cities alike in developing countries.

Abstract Water is a vital resource that makes it possible for human life forms to exist. The need for freshwater consumption has significantly increased in recent years. Seawater treatment facilities are less dependable and efficient. Deep learning systems have the potential to increase the efficiency as well as the accuracy of salt particle analysis in saltwater, which will benefit water treatment plant performance. This research proposed a novel method for optimization and modelling of the treatment process for saline water based on water level data analysis using machine learning (ML) techniques. Here, the optimization and modelling are carried out using molecular separation-based reverse osmosis Bayesian optimization. Then the modelled water saline particle analysis has been carried out using back propagation with Kernelized support swarm machine. Experimental analysis is carried out based on water salinity data in terms of accuracy, precision, recall, and specificity, computational cost, and Kappa coefficient. The proposed technique attained an accuracy of 92%, precision of 83%, recall of 78%, specificity of 81%, computational cost of 59%, and Kappa coefficient of 78%.

Abstract Fluorescence analysis is a sensitive and selective method that provides abundant information and does not result in sample destruction. This technology is widely used in the detection of dissolved organic matter in the environment. Some challenges with fluorescence analysis are its higher sensitivity so that it is sensitive to background signals, the difficulty of extracting useful information, and the complexity and diversity of analytical methods. This review summarizes recent applications of fluorescence analysis in water research for the characterization of pollutants, evaluation of water treatment processes, and monitoring of emerging contaminants such as drugs, disinfection by-products, and toxicity. Two-dimensional fluorescence and excitation–emission matrix fluorescence analysis methods are discussed, along with their advantages and disadvantages, and application scope. Methods for sample processing, instrument calibration, and data analysis are proposed. This review is an important source of information for the application of fluorescence technology in water research such as the analysis of emerging contaminants.

Abstract China's shale gas industry is developing rapidly, but the associated challenges of water resources shortage and water pollution are becoming more and more prominent. Hydraulic fracturing, the core process of shale gas extraction, consumes a large amount of water and produces refractory wastewater, closely linking shale gas fields with water resources. In this context, this article is to (1) summarize the characteristics of water consumption and wastewater production in typical shale gas fields; (2) introduce the current status of water intake and internal reuse and treatment of shale gas wastewater (SGW); and (3) analyse the challenges of water management in shale gas field. In order to promote the sustainable development of the shale gas industry, it is necessary to establish an efficient water management system according to local conditions. Making use of municipal reclaimed water in fracturing, promoting external reuse of SGW, strengthening the monitoring and safety guarantee of water use, and formulating national or regional water management guidelines can improve the utilization efficiency of water resources in shale gas fields.

Abstract The Qarhan Salt Lake is the second largest salt lake in the world and contains a rich and unique range of extremophiles requiring in-depth exploration. Halophilic microorganisms are promising resources for biotechnology due to their flexibility and survivability. The present study first isolated a novel strain of Halobacillus trueperi S61 from the Qarhan Salt Lake, then whole-genome sequencing and comparative genomics using third-generation PacBio combined with second-generation Illumina technology were performed. The whole genome of H. trueperi S61 identified 57,549 reads and consists of a complete circular chromosome of 4,047,887 bp with 43.86% genetic compound (GC) content and no gaps. A total of 139 non-coding ribonucleic acids (RNA) (including 86 tRNA, 30 rRNA, and 23 sRNA),16 gene islands with 260, 275 bp, and two prophages (with 82,682 in length) were predicted. The whole genome of H. trueperi S61 was annotated with 3,982 protein-coding genes using the Nr, Swissport, KOG, and KEGG databases for 3,980, 3,667, 2,998, and 2,303 genes. In addition, 561 carbohydrate enzymes and 4,416 pathogen–host interaction-related genes were identified. The protein function of H. trueperi S61 was focused on biological processes with distribution in gene transcription and amino acids as well as carbohydrate metabolism. The novel strain of H. trueperi S61 isolated from the Qarhan Salt Lake primarily preferred protein biological processes and antibiotic resistance, providing a potential resource for biotechnology.

Abstract To improve the performance of the membrane process in the treatment of oily wastewater, the combined effects of pretreatment, membrane modification, and optimization of operating parameters on the microfiltration membrane system were investigated. First, coagulation and adsorption were used as pretreatment steps. Polyaluminium chloride and ferric chloride were employed as coagulants, and granular activated carbon was used as an adsorbent. In the optimal coagulation condition (1 g/L polyaluminium chloride, pH 7.5), chemical oxygen demand (COD) was reduced by 96%, while in the optimal adsorption condition, in which large amounts of activated carbon were utilized, 48% of COD was eliminated. A membrane of polyethersulfone containing SiO2-g-polymethacrylic acid (PMAA) nanoparticles was then prepared by the non-solvent-induced phase separation method. To reduce fouling and increase the flux of the membrane, the SiO2 nanoparticles were first activated with amine groups and then PMAA was grafted onto the surface of the particles. Subsequently, the operating parameters were studied to optimize the performance of the polyethersulfone (PES)/SiO2-g-PMAA membrane using the response surface methodology (RSM) method. The results indicated that the flux of the modified membrane for pretreated wastewater was 72.2% higher than that of the PES membrane and non-pretreated wastewater at an optimum pressure of 2 bar and a flow rate of 3.5 L/min.