This study focuses on the East Qinling molybdenum mine area, where the pollution of heavy metals in the surrounding aquatic environment and the mineralogical characteristics of the associated sediment were analyzed. Furthermore, the study examined the migration behavior of molybdenum (Mo) during the leaching process from mine tailings to its mineralization in sediment. The findings revealed that the Mo concentration in the aquatic environment significantly surpassed the environmental background levels. Specifically, the maximum exceedance of Mo in the water samples was recorded at 21600 times above the baseline. Additionally, the geoaccumulation index (Igeo) values in both sediments and tailings exceeded 5. The sediments collected from aquatic environments impacted by AMD in the East Qinling molybdenum mining area predominantly comprised schwertmannite minerals, characterized by distinctive "poly spheroid" and "hedgehog" morphologies, and a substantial amount of Mo was immobilized within the mineral structure. In mine tailings, molybdenum (Mo) predominantly exists in the oxidation state of Mo(VI), whereas in schwertmannite, both Mo(VI) and Mo(IV) are present. This indicates a significant change in the valence state of Mo during its migration from tailings to sediments. Moreover, leaching experiments demonstrated that Mo associated with schwertmannite can be re-released into the environment, the processes were significantly influenced by the mineralogical characteristics of schwertmannite. Specifically, schwertmannite with higher crystallinity was found to be more effective in immobilizing Mo.

To investigate the spatio-temporal variations, influential factors and environmental health effects of negative air ions (NAIs) in Hainan tropical rainforests, a mobile comprehensive measurement platform was utilized to carry out field observation during typical tourist season (January), four types of typical forest stands (evergreen broad-leaved, deciduous broad-leaved, coniferous and bamboo forests) at eleven different altitudes in the Wuzhishan area of the Hainan Tropical Rainforest National Park were measured. The concentrations, spatiotemporal variations of NAIs, and their relationships with forest types, meteorological factors, air quality, and volatile organic compounds (VOCs) were analyzed. A comprehensive evaluation method for the ecological health function of tropical rainforest based on the Forest Health Index (FHI) was established. The results showed that the NAI concentration in the Wuzhishan area was relatively high (3541±882) moles/cm³, reaching Level VI of the World Health Organization's air freshness classification standard. The NAI concentration was increased with altitude initially and then decreased. Coniferous forest was found to have the highest NAI concentration, followed by broad-leaved forest, with bamboo forest having the lowest. A total of 66VOCs were detected, with sesquiterpenes and oxygenated organic compounds accounting for over 80%. NAIs were shown significant positive correlations with relative humidity, fine particulate matter, and monoterpenes, and significant negative correlations with sesquiterpenes and aromatic hydrocarbons. The FHI in the afternoon was generally found to be higher than that in the morning, with most sampling sites reaching Level II or above.

Oxygen vacancy-rich magnesium oxide (OV-MgO) microrods were prepared through the combination of chemical precipitation method with high-temperature calcination. The effects of adsorbent dosage, pH values of the solution, coexisting ions and humic acid on the phosphate removal performance were explored. The adsorption kinetic and isotherm models were used to analyze the mass transfer process and the equilibrium characteristics of phosphate adsorption. X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) were adopted to reveal the phosphate adsorption mechanisms. The results indicated that OV-MgO microrod was a mesoporous material with a total pore volume of 0.18cm³/g, and had a good acid resistance. The phosphate adsorption was influenced by SO₄²⁻ and HCO₃⁻ ions, but its adsorption capacity only decreased by 5.18% and 4.67%, respectively, exhibiting an extremely high selectivity. NH₄⁺ and Ca²⁺ ions present in the solution contributed to the phosphate adsorption based on the formation of struvite crystals and calcium phosphate precipitates. The adsorption of phosphate on OV MgO nanorods followed the fractal-like pseudo-first-order kinetic model (Adj. R²=0.9979 and RMSE=3.25). The fitting result of the Vermeulen model indicated that the intraparticle diffusion was the rate-controlling step. The maximum adsorption capacity predicted by the Langmuir isotherm model was 267.1mg/g (as PO₄³⁻-P). The adsorption mechanisms of phosphate mainly included ligand exchange, surface precipitation and oxygen vacancy capture.

Achieving anaerobic ammonium oxidation (Anammox) in low ammonia nitrogen wastewater represents a significant challenge for municipal wastewater treatment plants. This study employed a mainstream Anammox continuous-flow oxygen-limited biofilm system (DO: 0.4~0.7mg/L) and investigated the nitrogen removal performance for treating simulated domestic sewage with low ammonia nitrogen content under different influent carbon-to-nitrogen (C/N) ratios (C/N: 2~5). Long-term experimental results indicated that a C/N ratio of 3.5~4.5 achieved over 85% total nitrogen (TN) removal efficiency. There was a positive correlation between activity of Anammox bacteria (SAA) and the nitrogen removal efficiency, with the highest SAA observed at a C/N ratio of 4. Additionally, the C/N ratio significantly influenced the extracellular polymeric substances (EPS) composition of the biofilm, with the highest protein-to-polysaccharide ratio (PN/PS) and most stable biofilm structure observed at C/N:4. Metagenomic analysis identified Candidatus Kuenenia stuttgartiensis and Candidatus Brocadia sinica as the dominant species, with relative abundances of 21.5% and 4.7%, respectively. A diverse microbial community, including complete ammonia oxidizers (Comammox), and heterotrophic denitrifiers, contributed to microbial community structure in the system. Nitrogen metabolic analysis further uncovered the involvement of partial denitrification genes (HZS、hdh) and Anammox genes (HZS、hdh) in nitrogen removal processes, thus ensuring stable and efficient mainstream nitrogen removal. Research findings are expected to provide a novel option of mainstream anammox-based nitrogen removal process for wastewater treatment plants.

To understand the characteristics of microbial communities along the anaerobic ammonia oxidation (ANAMMOX) system, this study explored the diversity, structure, species network, and functional features of microbial communities in sludge with different morphologies along the flow direction in a long-term operated up-flow anaerobic sludge bed (UASB) ANAMMOX system. The results showed significant differences (P<0.05) in the abundance of AnAOB genes in sludge with different morphologies along the anaerobic ammonia oxidation system. The abundance of AnAOB genes in the bottom granular sludge (KL) was 2.12×10¹⁰copies/g VSS, which was significantly higher (P<0.05) than that in sludge with other morphologies along the system. There were significant differences (P<0.05) in the microbial diversity of sludge with different morphologies along the system, but no obvious change patterns were observed. The dominant bacterial phyla (relative abundance>1%) in sludge with different morphologies were Chloroflexi, Planctomycota, Proteobacteria, Bacteroidota, Acidobacteriota, and Actinobacteriota. The top 10genera in terms of relative abundance were norank_f_norank_o_SBR1031, Candidatus_Kuenenia, norank_f_Anaerolineaceae, Nitrosomonas,Limnobacteriota, norank_f_PHOS-HE36, Denitratisoma, Denitratisoma, and OLB13norank_f_ A4b. There were significant differences (P<0.05) in relative abundance among different samples. There were significant differences (P=0.001) in the microbial community structure of sludge with different morphology along the process. Network analysis found differences in the structure and topological properties of microbial networks among different morphologies of sludge. Specifically, the average degree and center tightness of flocculent sludge in sedimentation tank (CD) and biofilm in the effluent pipe (XK) were higher than those in other samples along the system, indicating a closer correlation among microbial communities. PICRUSt2analysis revealed that the abundance of functional genes related to metabolic pathways was significantly higher than that of other functional genes. Additionally, there were significant differences (P<0.05) in metabolic functional genes abundance among different morphologies of sludge along the process. The relative abundance of nitrogen metabolism functional gene hao was much higher than that of norB, while the abundance of the narG gene was 20.8 to 733.9times that of nirS, indicating activeness of partial nitritation and partial denitrification functions within the system. The anaerobic ammonia oxidation system exhibits significant heterogeneity in the microbial communities of sludge with different morphologies along the process, but no distinct regularity is observed.

FeMnCoNi-O nanoparticles (NPs) with outstanding structural stability and catalytic performance were synthesized by coprecipitation and consequent calcination method. The FeMnCoNi-O NPs were carefully characterized by X-Ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analyzer (TG) and X-ray photoelectron spectroscopy (XPS) techniques. Furthermore, the obtained catalyst was applied to activate potassium persulfate (PMS) and degrade Rhodamine B (RhB). The effects of reaction conditions such as the concentration of the RhB, PMS and catalysts concentration, the kinds of pollutant and aqueous pH values, on the degradation process and the recycling performance were systematically investigated. Via the calcined treatment (200℃, 2h), the final product was the multi-metal oxide, which exhibited enhanced catalytic performance for the RhB degradation. FeMnCoNi-O NPs can achieve complete degradation of RhB (20mg/L) in 10minutes by activating trace amounts of PMS (0.2mmol/L). With the help of free radical quenching experiment and XPS analysis, it is found the main active substances in the degradation system were ¹O₂ and SO₄^·- generated via persulfate activation.

In this research, BPS and BPF with sublethal dose were selected to compare the difference and combined toxicity of neurodevelopmental toxicity in zebrafish from four aspects: developmental phenotype, motor behavior, vascular development and neurotoxicity. The results showed that both BPS and BPF of LC5 induced apparent deformities in zebrafish, such as inhibiting the development of swimming sac and yolk sac. Exposure to BPS and BPF can affect the early motor behavior of zebrafish, which is potentially associated with damage to the cardiovascular system and nervous central system. BPS and BPF caused abnormal cardiovascular development and shortened caudal vein (CV) width in zebrafish. The abnormal transmission of DA, AChE and NO neurotransmitters leads to the impaired development of zebrafish neurons, which has a direct impact on the function of the lateral nervous system, and then leads to the impaired early motor behavior of zebrafish. BPS and BPF show different toxicity differences in specific indicators. BPF exposure is more likely to induce tissue and organ toxicity in zebrafish, while the direct toxicity of BPS is less than that of BPF, which is more manifested at the molecular level, indicating that there is a certain degree of difference in the mode of action of the two. In addition, combined with the analysis of the combined action of concentration addition model, the addition action between BPS and BPF is mainly. The results of this study provide a reference for health risk assessment and risk warning after exposure to BPS, BPF and their mixtures.

To understand nitrogen pollution and sources of Laizhou Bay, nitrogen sources and transformation processes in the coastal rivers entering the sea of Laizhou Bay were studied. Water quality parameters, nitrogen content, and stable isotopes were used to clarify the sources and key processes in river estuary. The results indicate strong temporal and spatial consistency between δD and δ¹⁸O of water, EC, and salinity, suggesting significant seawater mixing effects in the estuary, which was significantly weakened upstream of the river. NO₃^--N was found to be the dominant form to inorganic nitrogen in most reaches of the river during high flow and low flow seasons, ranging from 37.2% to 81.7% and 29.5% to 95.9%, respectively, except for a few sites. Furthermore, extreme values of ρ(TN) and ρ(NH₄⁺-N) values were observed at some sample sites during low flow season, which were significantly higher than those during the high flow season. Some water samples had ρ(NH₄⁺-N) values exceeding 2mg/L, resulting in an inferior Category V water quality. The long-term variation of ρ(NO₃^--N) from 2005 to 2023 showed an initial increase followed by a decrease in rivers entering Laizhou Bay. The δ¹⁵N-NO₃^- varied from +5.7‰ to +18.6‰ and from +4.5‰ to +20.0‰ during the high flow and low flow seasons, respectively, while the δ¹⁸O-NO₃^- varied from +4.2‰ to +13.8‰ and from -0.5‰ to +20.1‰, with no obvious seasonal variations. The nitrate isotope results showed that nitrification was major process affecting riverine nitrogen entering Lanzhou Bay, and that some river samples were also influenced by denitrification. During low flow season, NO₃^--N at the low salinity sampling sites was mainly sourced from manure and sewage, while most estuary sites during the high flow season were affected by the salty tide backflow, and agricultural fertilization impacted most river sections. This study provides insights into the emission characteristics of nitrogen pollution sources and spatial and temporal variability in Laizhou Bay’s coastal zone estuaries, offering valuable research demonstrations and data references for future prevention, control, and management efforts for nitrogen pollution in rivers entering the sea around the Bohai Sea.

Water pollution incidents were collected, and the characteristics of the incidents and their impact on population health were summarized. The types of water pollution incidents were classified as industrial pollution, agricultural pollution, and urban pollution. Industrial pollution were primarily caused by anthropogenic emissions and contaminant leakage. The pollutants were primarily heavy metals and chemicals. These pollutants were not usually directly affecting human health but resulted in the most economic losses once they occurred. Agricultural pollution, encompassing arable land pollution and animal husbandry pollution, was leading to economic losses with no serious health damage being caused. Urban pollution was being closely related to human health, and the health consequences caused by microbial pollution were the most frequent, primarily acute damage. The physiological and psychological health of the population were affected after the occurrence of the pollution incidents. Limited research had been conducted on residual water pollution and its chronic long-term effects on public health. The health risk assessment of residual pollution was worth being explored.

This study examines the impact of cultural and tourism integration on green total factor productivity in China, utilizing provincial panel data from 2010 to 2021 and employing both static panel models and system GMM models. The findings reveal a nonlinear "U-shaped" relationship, where culture and tourism integration initially suppresses but ultimately enhances green total factor productivity, contingent upon achieving a preliminary level of coordination. Regional analysis shows that this "U-shaped"relationship is present only in the highly integrated eastern regions. Additionally, market environment and industrial agglomeration significantly moderate the relationship between culture and tourism integration and green total factor productivity. The advanced industrial structure emerges as the ultimate pathway through which culture and tourism integration fosters improvements in green total factor productivity. Based on these insights, targeted recommendations are proposed to promote culture and tourism integration, thereby empowering green total factor productivity.