To explore the hydrochemical characteristics and hydraulic connections of different aquifers in the northern mining area of the Zhungeer Coalfield, and to reveal the regional water circulation patterns under coal mining activities, a total of 39water samples were collected from different aquifers in the mining area. The hydrochemical characteristics, controlling factors, and hydraulic connection degrees were analyzed using methods such as Piper trilinear diagrams, Gibbs diagrams, ion ratio analysis, chloride-alkalinity index, factor analysis, and connectivity index. The results show that the water in the mining area is generally weakly alkaline. The main hydrochemical type of the Quaternary and Shiqianfeng Formation aquifers is HCO^--Ca type water, which is mainly influenced by silicate weathering and mining activities, with positive cation exchange occurring. The main hydrochemical type of the Zhidan Group aquifer is HCO₃-Ca type water, followed by HCO₃-Na and Cl-Ca types. Its sources are mainly influenced by the weathering dissolution of silicate rock minerals and the impacts of mining and agricultural activities, with positive cation exchange occurring. The main hydrochemical type of mine water is Cl-Ca type water, which is influenced by the weathering dissolution of silicate and evaporite minerals and mining activities, with reverse cation exchange occurring. The hydraulic connectivity indices between the Quaternary aquifer and the Zhidan Formation, and between the Zhidan Formation aquifer and the Shiqianfeng Formation are 27% and 20%, respectively, indicating the presence of hydraulic connections. The hydraulic connectivity index between the Shiqianfeng Formation aquifer and the mine water is 39%, indicating a weak hydraulic connection.

In this study, the rates of denitrification and anammox, as well as their contributions to nitrogen removal, were quantified using the ¹⁵N isotope labeling technique in the riparian zones and sediments of different sampling sections within the 3rd Drainage Ditch in Ningxia's saline-alkali region. By integrating metagenomic sequencing and quantitative PCR (qPCR) analysis of functional genes, the influences of physicochemical properties, functional gene abundances, and microbial community structures on nitrogen removal processes in these two matrixes were systematically investigated. The results revealed that denitrification rates (1.22~3.75μmol N₂/(kg·h) were significantly higher than anammox rates (0.16~0.48μmol N₂/(kg·h) in both riparian zones and sediments (P<0.05), contributing 83.91%~92.95% and 7.05%~16.09% to total nitrogen removal, respectively. This indicates that denitrification is the dominant nitrogen removal pathway in the studied drainage ditch system. Sediments exhibited significantly higher denitrification rates than riparian zones (P<0.05), while no significant difference in anammox rates was observed between the two zones (P>0.05). Regarding functional genes, the abundance of the denitrification gene nirK was significantly higher in riparian zones than in sediments (P<0.05), whereas the opposite trend was found for nirS. Notably, the combined abundances of denitrification genes (nirK + nirS) were significantly greater than those of anammox-related genes in both matrixes (P<0.05). Microbial community analysis showed that Nitrososphaera was the most dominant genus among nirK-type denitrifiers in riparian zones, while Dechloromonas dominated the nirS-type denitrifier community in sediments. Environmental factors regulated microbial activity by influencing the abundance and expression of functional genes, thereby driving nitrogen removal processes. Higher total organic carbon (TOC) content, more anaerobic micro-environments, and greater functional gene abundances in sediments were identified as core driving factors contributing to their significantly enhanced denitrification capacity compared to riparian zones.

To investigate the fungal community structure, diversity, and influencing factors in three habitats (surface water, sediment, and riparian soil) of the Qingshui River in Ningxia, 22 sampling sites were established along the river in 2022. Sampling was conducted during the three hydrological periods: the normal period (May), the wet season (July), and the dry season (December). High-throughput sequencing technology was employed in conjunction with environmental factor measurements and multivariate statistical analyses. The results showed that the α-diversity of fungi in surface water was lower than that in sediment. However, the community structure in surface water was more sensitive to hydrological periods. In contrast, the fungal communities in sediment and riparian soil showed higher similarity. The dominant phyla were Chytridiomycota, Ascomycota, and Basidiomycota, and Fungi_gen_Incertae_sedis and Fusarium were identified as the key dominant genera. Water temperature (WT), pH value, bicarbonate (HCO₃^-) and calcium (Ca²⁺) in surface water, pH value, conductivity (EC), available potassium (AK), total phosphorus (TP) in sediments, pH value, total dissolved solids (TDS), ammonia nitrogen (NH₃-N) in interstitial water, water-soluble fluorine (Ws-F), exchangeable calcium (Ex-Ca), total nitrogen (TN), TP in riparian soil had significant effects on fungal community. The changes of fungal indicator groups reflected the environmental characteristics of different hydrological periods: the accumulation of agricultural non-point source pollution in the normal period, the migration of organic pollutants in the wet season, and the accumulation of refractory organics and high saline-alkali environment in the dry season.

3C-SiC was synthesized via the sol-gel carbothermal reduction method, and BiVO₄/SiC composites were prepared using a hydrothermal approach. The Vis+BiVO₄/SiC+PMS system was constructed for the degradation of CIP. Under optimized conditions, 1.0-BiVO₄/SiC was added with a dosage of 300mg/L, PMS concentration of 2mmol/L, and initial pH of the reaction of 7—the system achieved a 93.63% CIP degradation rate within 40minutes, with the k of 0.05456min^-1. These values represented 3.34 times and 3.27 times enhancement compared to BiVO₄ and SiC, respectively. The catalyst was characterized by SEM, XRD, XPS, UV-Vis DRS and electrochemical workstation. The excellent photocatalytic performance of BiVO₄/SiC was attributed to the formation of a Z-scheme heterojunction, which could promote the separation of electron-hole pairs while maintaining the high redox activity of the catalyst. Therefore, the Z-Scheme heterojunction formed by BiVO₄/SiC could effectively promote the activation of PMS and generate more active species, thus accelerating the degradation process of CIP. The active species in the system were identified as h⁺、¹O₂、·O₂^-、·OH、SO₄·^--- through the free radical quenching experiment. The efficient degradation of CIP was realized through the interaction of free radicals and non-free radicals. Notably, the catalyst exhibited excellent stability, retaining 89.49% of its initial degradation efficiency after five consecutive cycles. This study not only presents a novel strategy for PMS activation using photocatalysts but also demonstrates its successful application in antibiotic degradation, offering a promising approach for the remediation of organic pollutants in aquatic environments.

In this study, nitrate and ofloxacin(OFL) with high detection rate in groundwater were taken as target pollutants, and the effects of iron denitrification microorganism(M) with different inoculation dosage on the removal of nitrate and OFL by the dual materials of micro ZVI/FeS₂ system was investigated. Also, the influence of the major water chemical parameters, nitrate and OFL concentrations on the removal of nitrate and OFL in the coupled system(ZVI/FeS₂+M) was studied. In addition, the enhanced mechanisms for removing nitrate and OFL in the coupled system were explored. The results showed that the iron denitrification functional microorganisms could significantly enhance the removal of nitrate and OFL by ZVI/FeS₂. When the mass ratio and total dosage of ZVI/FeS₂ were 2:1 and 16g/L, respectively, and the inoculation amount of M was 5.81g/L, the nitrate in the ZVI/FeS₂+M reaction system was almost completely removed within 168h, and the removal rate of OFL was as high as 90.44%. Meanwhile, the ZVI/FeS₂+M system showed a good adaptability at different temperatures(10~30℃), nitrate concentrations(25~150mg/L), OFL concentrations(500ng/L~200ug/L) and the presence of coexisting ions. The intervention of microorganisms greatly delayed the passivation and oxidation of the ZVI surface, and at the same time, it could increase the dissolution of FeS₂ to produce FeS, Fe²⁺ and S^2-, which were all beneficial to the removal of pollutants. The removal of nitrate and OFL by ZVI/FeS₂+M after six cycles was still kept at 73.80% and 79.25%, which was still higher than that of the ZVI/FeS₂ (62.73% and 60.60%) in a one cycle experiment, indicating that the coupled system(ZVI/FeS₂+M) is a feasible method for remediating nitrate and antibiotic-containing groundwater.

Ultraviolet spectra, infrared spectra, and fluorescence spectroscopy with parallel factor analysis were used to explore the complexation heterogeneity and underlying mechanisms between tetracycline (TC) and dissolved organic matter (DOM) from hydrochars of three sources (i.e., sludge, chicken manure, and straw). Results showed that all three hydrochar DOM types exhibited high hydrophilicity and low aromaticity. Among these, straw-derived hydrochar DOM showed relatively higher aromaticity and larger molecular weight, whereas it had lower dissolved organic carbon (DOC) content and richer surface oxygen-containing groups. In contrast, sludge-derived hydrochar DOM possessed the highest DOC content but the lowest aromaticity and molecular weight. The fluorescence quenching of the three hydrochar DOMs by TC was static quenching. Sludge- and chicken manure-derived hydrochar DOMs showed significant quenching effects. The complexation constants (lgK) ranged from 4.48to 5.81 for sludge-derived hydrochar DOM and from 5.94 to 6.33 for chicken manure-derived hydrochar DOM, with corresponding capacities (f) of 0.21~0.40 and 0.14~0.46, respectively. Further analysis indicated that TC tended to quench the protein-like components in hydrochar DOM. The chicken manure-derived hydrochar DOM exhibited the strongest binding affinity with the protein-like component (C4), with the highest lgK of 6.33 and f of 0.46. The complexation effects between different source-derived hydrochar DOMs with TC varied, influencing the environmental occurrence, migration, and bioavailability of TC.

Aiming at the characteristics of complex sources and scattered emissions of antibiotics, a method for estimating antibiotic emissions was established. Based on the population and the number of livestock and poultry in the basin, the antibiotic emissions in different regions were obtained by combining the consumption coefficients of different organisms and the sewage treatment rate. Using the emission loads as the input data, the semi-distributed hydrological model-SWAT model was established to simulate the ciprofloxacin (CFX) and sulfamethazine (SMZ) in the middle and upper reaches of the Huaihe River. The results showed that the livestock breeding scale, regional population, sewage treatment capacity and large-scale management measures are the main influencing factors of antibiotic emissions in each city. The results of model validation showed that the simulated concentrations of CFX and SMZ are basically in the same order of magnitude as the monitoring values, with the good accuracy. In summer, the concentrations of CFX in the main channels of Huaihe River were almost all lower than 7.26ng/L. And in winter, the concentrations of CFX in the main channels of Huaihe River almost all were lower than 190.3ng/L. In summer, the concentrations of SMZ in the main channels of Huaihe River almost all were lower than 8.7ng/L, while in winter, the concentrations of SMZ in the main channels of Huaihe River almost all were lower than 38.11ng/L.

Based on confirming that the linear perfluorohexanesulfonate (L-PFHxS) could be degraded and defluorinated in a biomimetic system, the degradation products of isotope-labelled (¹³C) L-PFHxS (MPFHxS) were qualitatively analyzed, and the degradation mechanisms of L-PFHxS were then clarified. Two ¹³C-labeled perfluorocarboxylates (PFCAs, i.e. ¹³C₃-perfluorohexanoate and ¹³C₃-perfluorononanoate), eight native PFCAs (perfluorocarbon chain length ranged from C1 to C8), and seven native perfluoroalkylsulfonates (PFSAs, perfluorocarbon chain length ranging from C3 to C8, including linear and branched PFHxS), had been identified as the biomimetic degradation products of MPFHxS. The degradation pathways of L-PFHxS were proposed as follows: L-PFHxS were firstly reduced to C₆F₁₃· radical by cleavage of C-S bond, and then transformed to perfluorohexanoate through a series of hydrolysis. C₆F₁₃· radical or/and L-PFHxS were further reduced to form C_nF_2n+1· (n = 1, 2or 3) radicals, and these radicals were chain-lengthened by stepwise addition of 0 ~ 2C₃F₆ moieties and eventually transformed to various degradation products with different perfluorocarbon chain length via a series of hydrolysis (PFCAs) or combination reaction with sulfonyl hydroxide radical (PFSAs).

This study investigated the colonization process of ammonia-oxidizing microorganisms (AOMs) on five common types of microplastics (MPs) as well as the potential nitrification niches of MPs in water supply systems, with the methods of biofilm simulation reactors, physicochemical characterization of MPs and microbiological analysis techniques. The results indicated that chlorination and microbial colonization led to an increase in the crystallinity of microplastics and the formation of hydrophilic groups such as carbonyl and hydroxyl moieties. The abundances of amoA genes of AOMs on microplastics ranged from (1.54±0.02) × 10 to (3.07±0.64) × 10¹ copies/g. Comammox was predominant on most of the microplastics. Ammonia-oxidizing archaea (AOA), which was highly chlorine-resistant, was found to be predominant on the MPs only after chlorination for 42days. The total abundance of AOMs exhibited a positive correlation with microplastic crystallinity on unchlorinated microplastics, which was particularly obvious on higher intrinsic crystallinity MPs, ^i.e., polyethylene (PE) and polypropylene (PP). However, this correlation was not observed after chlorination treatment. Diversity analysis of AOMs colonizing on microplastics revealed that AOA on unchlorinated MPs were more closely related to soil-derived AOA. On the contrary, AOA on chlorinated MPs was more closely to aquatic AOA.

To explore the mechanisms by which gut microbiota dysbiosis influences the health effects of microplastics (MPs), a systematic search was conducted across five English-language databases (PubMed, Embase, Scopus, Cochrane, and Web of Science) and three Chinese-language databases (CNKI, Wanfang Data, and China Biomedical Literature Database). Studies addressing gut microbiota-mediated health effects of MPs exposure in mice and rats were identified and reviewed. A total of 27 studies met the inclusion criteria. The animal models used were primarily C57BL/6 mice, aged between 4 and 12 weeks, mainly male. The MPs used were mainly polystyrene, with particle sizes ranging from 0.05~53μm. The primary exposure routes were oral gavage and free drinking water, with exposure durations ranging from 3 to 13 weeks. Microbial community analysis was primarily performed using 16S rRNA gene sequencing. The studies investigated gut microbiota on harm through the gut-organ axis (including the liver, brain, testes, bone marrow, and lungs) and the gut-function axis (encompassing immune and metabolic functions). Intestinal microflora mediates the damage of MPs to mice through various metabolic pathways (such as amino acids and lipids) and signaling pathways (including TLR 2-Myd 88-NF-κB and intestinal microflora -HIF 1α/PTBP 1). Further clinical studies are warranted to better elucidate the potential mechanisms by which gut microbiota modulates the health effects of MPs exposure in humans.