Addressing the drawbacks of iron-based tailings, such as high salinity and alkalinity, low nutrient content, poor water retention, and difficulty in effective utilization, this study utilize the functional microbial system to improved and restored the ecological function of iron tailings, and alfalfa was chosen as the pioneer plant to study the effect of the composite flora on the improvement and restoration of iron tailings by analysing the growth indexes of the plants. Results from pot experiments indicated that the average height of alfalfa in the treatment groups increased by 63.99% compared with the control group, with a decrease in tailings pH and a significant increase in nutrient elements such as urease enzyme activity, catalase enzyme activity and effective phosphorus. Microbial diversity analysis revealed that the abundance of nitrogen-fixing related microbial groups, such as the Nitrospirae, increased by approximately one-fold compared to the untreated groups. Therefore, the functional microbial system has the potential to regulate the acidity of iron tailings, provide nutrients to promote plant growth, increase the abundance of sterol bacteria microbial communities, enhance metabolic capabilities and nitrogen-fixing potential, and contribute to rehabilitate of iron tailings.

The persulfate-based advanced oxidation technology for antibiotic-containing wastewater treatment has become a current research hotspot in water treatment. Carbon-based materials have been used as green materials for activating persulfate due to their chemical stability and absence of secondary pollution. However, the catalytic activity of undoped or modified carbon materials is limited. This paper reviews strategies to enhance the catalytic performance of carbon materials, including non-metallic doping, metal doping, and carbon-based composites, and summarizes the new active sites formed by these strategies, as well as the connection between the types of active species produced by activated persulfate. In conjunction with the existing studies on the degradation of antibiotics by activated persulfate in carbon-based materials, the mechanisms of activation of persulfate by carbon-based materials (including free radicals, single-linear oxygen, electron transfer, and high-valent metal-oxygen species), and the methods to identify and determine the active species are concluded. Finally, the susceptible oxidation sites of tetracyclines, sulfonamides, and fluoroquinolones antibiotics, their linkages with active species, as well as the application of this technology in treating antibiotic-containing waters. These results can provide a reference for the development of carbon-based catalysts with high catalytic performance and stability, and their application to activated persulfate systems for efficient antibiotic degradation.

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.

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.

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 study, GCW was coupled with the advanced oxidation system based on Fe²⁺ activated O₂ to achieve efficient transmission and uniform distribution of chemical agents while continuously replenishment of oxygen to groundwater, so as to enhance the remediation effect of the Fe²⁺/O₂/ligand was advanced oxidation system. The variation law of groundwater flow field and enhanced transport effect of solute under the enhancement of GCW were clarified using two-dimensional simulation tank experiment combined with visualization methods such as tracer dyeing. In addition, sodium tripolyphosphate (STPP) was selected as the ligand, and the effect of advanced oxidation system on the remediation of p-nitrophenol (PNP) polluted aquifer was investigated by injection of chemicals into the well. The results show that GCW had achieved efficient transmission of chemical agents and provided sufficient O₂ for advanced oxidation reactions. Under the enhancement of GCW, PNP was degraded throughout the simulated tank, with an average degradation rate of 62% in 15h. The results provide a new insight for efficient remediation of organic contaminated groundwater.

The bimetallic NiCe-x(x=1:3, 2:2, 3:1, 0:1, 1:0) catalysts were successfully synthesized using the hydrothermal method and subsequently evaluated for their efficacy in the selective catalytic reduction of NO by CO(CO-SCR). The results indicated that compared to NiO and CeO₂ catalysts, the NiCe composite catalyst exhibited superior performance in simultaneously removing low-temperature CO and NO. Superior performance was demonstrated by the NiCe composite catalyst with a 3:1 ratio, which achieved over 90% NO conversion over an extensive temperature range of 200~450℃ and exhibited strong resistance to SO₂ and H₂O. Characterization indicated that the existence of Ni and Ce ions led to an increased specific surface area and accelerated redox cycling (Ce³⁺+Ni³⁺↔Ce⁴⁺+Ni²⁺), which improved denitrification activity. In-situ DRIFTS findings confirmed that adsorbed NCO played a crucial role as an intermediate in the CO-SCR process employing NiCe-3:1.

In response to the challenge of coexisting high concentrations of fluoride (F^-) and sulfate (SO₄^2-) in photovoltaic wastewater, based on the principle of nucleation crystallization pelleting process (NCP), its efficacy and mechanisms for removing F^-in such ion coexistence systems were thoroughly investigated. Our study demonstrated that under conditions (nucleation inducer dosage 4.46gMgCl₂/gF, flow rate 67.8×10^-4m³/h, static bed height 30%, and seed particle size 80~100mesh, F^- removal efficiency reached up to 90%. To further validate the stability of the process system, continuous flow defluorination experiments were conducted over 120h. In the first stage (0~40hours), F^- removal efficiency stabilized at approximately 89%, increasing to over 92% in the second stage (40~120hours), with granule purity exceeding 90%. Analysis using XRD and Roman revealed that F^- predominantly adhered to seed surfaces in the forms of magnesium fluoride (MgF₂) and sodium magnesium fluoride (NaMgF₃). Static water contact angle tests and SEM-EDS characterization indicated that granules exhibited greater hydrophobicity compared to the raw seeds and formed a loose porous structure, thereby increasing their specific surface area and enhancing F^- removal. The ZP revealed that in pH 6~8, the seed surface was positively charged, and F^- was mainly concentrated around the surface of the seeds by electrostatic attraction, and then driven by the inducer to nucleate and grow into dense granulation on the surface of the seeds, effectively separating F^- from water.

Electroplating is one of the most significant sources of perfluorinated and polyfluoroalkyl substances (PFASs) in the environment. In this study, the occurrence of PFASs in soil of a relocated electroplating plant was analyzed. The probabilistic health risk was evaluated using Monte Carlo simulation, and the soil screening levels of PFASs were suggested. The soil samples were detected with 8PFASs, and perfluorooctane sulfonate (PFOS) was detected with the highest detection frequency of 89% and concentration of 388ng/g among the targeted PFASs. The distribution of PFASs in soil was impacted by the locations of production units. The total concentration and concentrations of single PFAS such as PFOS, perfluorohexane sulfonate (PFHxS) were significantly higher in soil at chromium plating department (P<0.05). Intake through human oral exposure of soil PFASs accounted for 75.2%~77.6%. Carcinogenic risk of perfluorooctanoic acid (PFOA) was 6.22×10^-11, showing no carcinogenic risk in soil. Non carcinogenic risk quotient of PFOS was larger than 1based on the deterministic values of the exposure factors, while other PFASs showed no non carcinogenic risk. Monte Carlo simulation showed that the risk quotient of PFOS ranged from 0.731 to 5.38, with 95% quantile being 3.85. The 95% quantile values of risk quotient of other PFASs were between 8.77×10^-6 and 0.0137. The soil screening levels of targeted PFASs ranged from 78 to 38826ng/g, and PFOS was found to have the most strict level of 78ng/g.

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.