The produced water from oil and gas fields is the largest by-product generated during the extraction of oil and gas containing organic, inorganic compounds and solid suspended matter. With increasingly serious environmental problems and strict legislation, how to effectively handle the produced water from oil and gas fields has become a problem that the petroleum industry must face. Based on the introduction of the basic principle and classification of membrane separation technology and its origin in the treatment of produced water from oil and gas fields, this paper focuses on elaborating the common membrane separation process flow, applications, membrane fouling mechanisms, control approaches, cleaning methods in the treatment of produced water, and the comprehensive cost comparison. Based on the comparative analysis of the advantages and disadvantages of the current membrane separation technology in the treatment of produced water from oil and gas fields, the suggestions and prospects for further development are put forward.

Membrane bioreactors (MBRs) integrate membrane separation with activated-sludge processes and are increasingly employed in wastewater treatment. Despite their advantages, MBRs can suffer from limited mass-transfer efficiency and operational instability. Advanced oxidation processes (AOPs) generate highly reactive species that enable rapid contaminant degradation, but their practical use is constrained by high energy demand and the potential for secondary pollution. Combining MBRs with AOPs therefore leverages membrane filtration, biological degradation, and oxidative destruction of recalcitrant compounds, providing a promising strategy for treating high-strength wastewaters. This review summarizes recent progress in MBR–AOP hybrid systems, including photocatalytic MBRs (ICPB), electro-catalytic MBRs (EMBR), integrated photo-/electrocatalytic MBRs, MBR-Fenton, and MBR-ozonation configurations. The various hybrids are compared in terms of catalyst selection, operational advantages, removal performance, and application scope. Current structural, operational, and scale-up challenges are discussed, and future research directions for MBR–AOP technologies are proposed.

Industrial wastewater comprises wastewater, sewage, and waste liquids generated during industrial production, primarily containing organic matter, nitrogen, phosphorus, inorganic salts, and other pollutants. These wastewaters typically exhibit a relatively simple composition but high concentrations of primary pollutants. Currently, processes such as coagulation-precipitation, oxidation ditches, and adsorption are widely employed for the advanced treatment of industrial wastewater. However, these methods often entail high operating costs and limited resource recovery potential, which are inconsistent with China's dual-carbon strategy. In recent years, membrane separation technology has gained widespread adoption due to its high separation precision, absence of by-products, and strong adaptability. By integrating membrane separation with other processes, it is possible to address the limitations of traditional methods while enabling the separation and recovery of specific substances based on size screening and charge effects. This paper focuses on organic carbon separation, nitrogen and phosphorus recovery, and inorganic salt desalination for lithium extraction, using dye wastewater, nitrogen-phosphorus wastewater, and salt lake brine as case studies. It systematically reviews current research and advancements in membrane-based resource recovery technologies for industrial wastewater, aiming to provide innovative approaches for industrial wastewater resource recovery in China.

Enhanced biological phosphorus removal (EBPR) is a widely used, cost-effective technology for eliminating phosphorus from wastewater. Its efficiency depends on the metabolic activity of polyphosphate-accumulating organisms (PAOs) and denitrifying PAOs (DPAOs). During shortcut biological denitrification via the nitrite pathway, nitrite can accumulate in activated sludge and protonate to form free nitrous acid (FNA). Elevated FNA concentrations inhibit PAO activity and destabilise overall EBPR performance. This review therefore summarises the inhibitory effects of FNA on EBPR microorganisms and elucidates the underlying mechanisms. The resulting insights can inform the design and operation of stable, high-efficiency EBPR systems.

To mitigate riverine pollution caused by phosphogypsum accumulation during phosphate mining, we developed an iron-based/calcium-oxide (CaO) composite capable of removing phosphorus from wastewater within 40 s. Static batch tests first quantified the phosphorus-removal capacity of CaO alone, followed by a comparison of three iron systems—microscale zero-valent iron (mZVI), mZVI + Fe2+, and mZVI + H2O2 + HCl. Subsequent combined-dosing experiments confirmed the composite's suitability for rapid phosphorus removal under simulated flood-season conditions, achieving outstanding efficiency within 40 s. Scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD) revealed a dense surface layer of iron–calcium phosphate precipitates. Synergy and cycling tests demonstrated excellent reproducibility and long-term stability. Overall, this work provides a practical solution for the rapid remediation of high-phosphorus effluents during flood events and promotes sustainable phosphorus recovery.

Excessive manganese content in groundwater, when used as a drinking water source, can lead to severe adverse effects on human productivity and daily life. This study designed an integrated purification system that integrates aeration with a fluidized bed containing birnessite and a gravity-driven ceramic membrane process. The system was operated for a total of 58 days to efficiently purify manganese-contaminated groundwater. Initially, a predetermined birnessite suspension was pre-aerated for 28 days without water production in the membrane pool, followed by the initiation of gravity-driven water production through the ceramic membrane. By the 38th day of the system's fluctuating operation, the concentration of manganese ions in the effluent was reduced to below 0.1 mg/L, which complied with the Chinese Health Standards for Drinking Water Quality (GB 5749－2022). Additionally, the membrane flux was finally stabilized at 9～10 L/(m2·h). Aeration effectively employs the lateral shear force generated by the bubbles to retard the deposition of birnessite on the membrane surface during operation, thereby maintaining the fluidized suspension state of birnessite in the membrane pool. Concurrently, the analysis of microbial-related indicators, along with Raman, XRD, particle size, SEM-EDS, and other characterization results, suggests that after manganese ions in the water were adsorbed by the birnessite particles, under the action of microbial oxidation and chemical oxidation by birnessite, a manganese-active filter membrane with self-catalytic oxidation properties was formed, realizing a virtuous cycle of highly efficient removal of manganese ions from groundwater.

This study examined the effect of pyrolysis temperature on the physicochemical properties of municipal sewage-sludge biochar and on the speciation of its heavy-metal constituents. Dewatered sludge was carbonised at 300 °C, 400 °C, 500 °C, 600 °C and 700 °C, and the resulting products were characterised to identify an optimal operating temperature. Higher temperatures enlarged the pore network of the biochar and caused pronounced organic-carbon loss, imparting a distinctly alkaline character. Pyrolysis removed more than 80% of the nitrogen, whereas total phosphorus and potassium concentrations increased; their plant-available fractions declined overall, yet remained comparatively high at 500 °C. Most heavy metals were retained in the residual fraction and became further immobilised during pyrolysis, thereby lowering bioavailability, although Pb and Ni showed increased mobility at 600–700 °C. Cadmium also persisted mainly in the residual form, but its elevated concentration still limits agricultural application of the char. Considering nutrient content, pH, and metal bioavailability, 500 °C is recommended as the optimal carbonisation temperature.

Core–shell silver/mesoporous-silica spheres (Ag@mSiO2) were synthesised via a hydrothermal route and incorporated into poly (vinylidene fluoride) (PVDF) to fabricate antibacterial dual-layer ultrafiltration membranes by co-casting followed by phase inversion. Membrane morphology and composition were characterised using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), whereas hydraulic performance, mechanical strength, fouling resistance and antibacterial activity were evaluated through pure-water permeation, cyclic filtration and bacteriostatic assays. Incorporation of Ag@mSiO2 progressively increased the water flux while maintaining a bovine serum albumin (BSA) rejection above 91%. At an Ag@mSiO2 loading of 0.3wt%, the pure-water flux rose from 373 to 536 L/(m2·h) and the flux-recovery ratio improved from 57.9% to 82.5%, indicating a substantial enhancement in antifouling performance. Moreover, higher nanoparticle contents produced a pronounced, dose-dependent antibacterial effect against Escherichia coli, confirming the excellent bioactivity of the hybrid membranes.

Fe-S/TiO2/GFC photocatalyst co-doped with Fe and S was prepared by sol-gel method and dip coating method with TiO2 as photocatalyst and glass fiber cloth (GFC) as carrier material. SEM, XRD, XPS, UV vis and other methods were used to analyze and characterize it. The results of the single factor experiment showed that when the initial pH value, light intensity, initial concentration of ibuprofen, and catalyst dosage of the ibuprofen solution were 5, 54 000 lux, 10 mg/L, and 0.15 g, respectively, the degradation rate of ibuprofen was the highest, at 80.7%, 80.71%, 81.64% and 82.11%, respectively. Through response surface modeling analysis, the optimal conditions for ibuprofen degradation were determined to be a pH of 5.4 for the ibuprofen solution, an initial concentration of 10.31 mg/L for the ibuprofen solution, and a catalyst dosage of 0.15 g. At this point, the ibuprofen degradation rate was 80.04%. The verification experiment found that the difference between the optimized actual response value and the predicted response value was about 0.5%, indicating that the response surface model has good fitting and reliability. Common cations in natural water bodies such as Na+, K+, Ca2+ and Mg2+ have almost no effect on the degradation process of ibuprofen. Common anions such as Cl- and HCO3- have a significant inhibitory effect on the degradation of ibuprofen, while SO42- has little effect. NO3- promotes the degradation of ibuprofen.

A gravity heat pipe–based two-stage seawater desalination and salt production system, driven by thermal oil, was designed and constructed. Using simulated seawater as the feed solution, the system's water production, energy consumption, efficiency, heat pipe thermal resistance, and equivalent convective heat transfer coefficient were analyzed under varying heat source temperatures prior to the discharge of concentrated brine. The desalination and salt production experiments were conducted at a heat source temperature of 140 °C to enable continuous production of both freshwater and salt. The results show that within the first hour of operation, increasing the heat source temperature leads to higher first- and second-stage water production and efficiency, lower total energy consumption, and higher equivalent convective heat transfer coefficients for both stages. Over extended operation, however, first- and second-stage water production, efficiency, and equivalent convective heat transfer coefficients generally decrease. Once steady-state conditions were reached, the primary and secondary water production rates were 1.08 kg/h and 0.58 kg/h, respectively, while their equivalent convective heat transfer coefficients were 1 240.37 W/(m2·K) and 284.68 W/(m2·K), respectively. Under these conditions, the overall system efficiency was 46.05%, and the corresponding salt production rate was 2.4 g/h.

In this study, nano calcium peroxide (nCP) was successfully synthesized via chemical precipitation method, which exhibited a large specific surface area (47.98 m2/g) and high purity (84.1%), demonstrating superior performance in degrading naphthalene (NAP) compared to commercial calcium peroxide (CP). Compared with the nCP/Fe(III) system, the chelating effect of citric acid (CA) significantly enhanced NAP degradation, increasing the NAP degradation efficiency from 14.1% to 91.0% within 180 min, indicating a strong promoting effect of CA on NAP degradation. The reactive oxygen species generated in the nCP/Fe(III)/CA system included hydroxyl radicals, superoxide anion radicals, and singlet oxygen, with hydroxyl radicals being the dominant radical responsible for NAP degradation. The superoxide anion radicals indirectly facilitated NAP degradation by accelerating the Fe(II)/Fe(III) cycle. Chloride ions, humic acid, and low concentrations of bicarbonate ions did not significantly affect NAP degradation, whereas high concentrations of bicarbonate ions significantly inhibited NAP degradation in the nCP/Fe(III)/CA system. In groundwater, the adverse effects of environmental conditions can be mitigated by increasing the reagent dosage, demonstrating the potential of the nCP/Fe(III)/CA system for remediating NAP-contaminated groundwater.

Bentonite-modified PCL-PEG-PCL composites were fabricated through solvent evaporation coupled with physical encapsulation. The PCL-PEG-PCL copolymer, synthesised by melt ring-opening polymerisation, provided the structural framework, whereas bentonite served as the adsorptive phase. The material's capacity to remove crystal violet (CV) from aqueous solution was evaluated and the adsorption mechanism elucidated. Under optimal conditions (PEG6000, 9.303 3 g; bentonite, 8.006 4 g; CV concentration, 500 mg/L; sorbent dosage, 0.7 g/L; 303 K; 240 min), the maximum adsorption capacity reached 527 mg/g. After five adsorption–desorption cycles, the composite retained 87% of its initial capacity. Kinetic and equilibrium data fitted the pseudo-second-order and Langmuir models, respectively; film diffusion governed the initial uptake, whereas intraparticle diffusion controlled the later stage. FT-IR spectra confirmed CV immobilisation, while SEM–EDS revealed a rough, porous surface containing adsorbed dye. XRD patterns showed that the crystalline structure of the composite remained stable after adsorption, and thermogravimetric analysis indicated adequate thermal stability. Altogether, the bentonite-modified PCL-PEG-PCL composite exhibits strong affinity for basic dyes and holds considerable promise for wastewater remediation.

To shorten the drinking water treatment process and improve the quality of the effluent, a study was conducted to evaluate the purification effect on water quality as well as the removal ability of dissolved organic matter and inorganic ions using a microfiltration (MF)-ultrafiltration (UF)-nanofiltration (NF) total membrane process for treating natural surface water. This study assessed the purification efficiency of the process for water quality, focusing on its ability to remove dissolved organic matter and inorganic ions. Using an experimental design, an integrated membrane process was applied to treat water samples from the Dongping Lake. The removal rates of UV254, TOC, conductivity, TDS, and various ions were measured, and the effects of different processes on organic matter of varying molecular weights were analyzed. The results demonstrate that the combined process effectively removed dissolved organic matter from the raw water of Dongping Lake. Removal rates of 92.7%, 97.89% for UV254, 75.83%, and 55.1% were achieved for TDS. Furthermore, the MF and UF processes effectively removed macromolecular organic matter, whereas the NF process significantly eliminated small- and medium-molecular-weight organic matter. In addition to removing organic matter, the full membrane process effectively removes inorganic ions from the water. The comprehensive experimental results indicate that the MF-UF-NF integrated membrane process not only efficiently removes organic matter and inorganic ions from water but also improves water quality, meeting the requirements for safe drinking water production. The experimental results indicate that the MF-UF-NF integrated membrane process effectively removes organic matter and inorganic ions while improving water quality to meet safe drinking water standards. Therefore, this process has the potential to serve as an efficient water treatment technology, offering critical data for improving drinking water quality and for advancing water treatment methods.

Metal-organic gels (MOGs) are coordination hydrogels formed by the self-assembly of metal ions and organic ligands; their mechanical robustness and chemical stability make them attractive for adsorption, catalysis and molecular separation. In this study, an Fe/Al-based MOG (MOG-Fe/Al) was synthesised and assessed as a flocculant for pulp-mill cypress wastewater. Under the optimised conditions of 1.0 g/L dosage, 100-fold diluted wastewater, pH=9, 30 °C and 12 h contact time, the material achieved 98.3% turbidity removal. SEM, FT-IR, XPS, XRD, TG and BET analyses revealed a porous, irregular morphology with a specific surface area of 360.5 m2/g, classifying the gel as a micro/mesoporous adsorbent. The large surface area and hierarchical pore structure account for the excellent flocculation performance, underscoring the potential of MOG-Fe/Al for practical application in pulp-mill wastewater treatment.

Sulfate-reducing bacteria (SRB)-mediated precipitation provides a promising strategy for remediating acid mine drainage (AMD). In batch experiments with manganese- and magnesium-rich acidic wastewater, we examined the cyclical sedimentation-adsorption capacity of an enriched sludge consortium to remove Mn2+, Mg2+, NH3-N and chemical oxygen demand (COD). High-throughput 16S rRNA sequencing showed that Desulfobacterota, Firmicutes and Proteobacteria predominated, forming a Desulfurivibrio-like SRB community. Expansion of this consortium markedly lowered SO42- concentrations and simultaneously reduced the target pollutants. Optimal growth occurred at 30 °C, pH 7.0 and an initial SO42- concentration of 1 000 mg/L. Under these conditions, treatment of real AMD achieved removal efficiencies of 80.5% for Mn2+, 80.7% for Mg2+, 33.3% for NH3-N, 81.9% for COD and 73.4% for SO42-. These findings demonstrate the engineering potential of SRB-based anaerobic processes for full-scale remediation of manganese- and magnesium-laden AMD.

Biological nutrient - removal processes perform poorly when the influent contains insufficient carbon, and supplementation with external chemicals or carbon sources greatly increases operating costs. Side-stream enhanced biological phosphorus removal (S2EBPR) has therefore gained attention as a cost-effective alternative for low-carbon wastewaters. In this study, a sequencing-batch reactor (SBR) equipped with an S2EBPR side stream was operated at various readily biodegradable COD-to-phosphorus ratios (rbCOD/P), sludge diversion percentages, and side-stream sludge-retention times (SRTSS). With 20% of the return sludge diverted to the side-stream and SRTSS maintained at 72 h, the system achieved stable performance at an influent rbCOD/P of 18.3: phosphate-removal efficiency averaged 90.9% and the P-release/acetate-uptake ratio reached 0.41 mol P mol-1 C. Increasing the diversion ratio to 25% while shortening SRTSS to 57.6 h impaired phosphorus removal under the same low-carbon conditions owing to weakened microbial selection and reduced activity of polyphosphate-accumulating organisms (PAOs). Although in-situ sludge fermentation increased the ammonium load to the mainstream reactor by about 13%, the additional carbon generated offset this impact. High-throughput sequencing showed that fermentative Tetrasphaera species dominated the PAO community and likely acted synergistically with glycogen-accumulating organisms. Maintaining SRTSS > 72 h favoured PAO dominance at low rbCOD/P values. Overall, the results demonstrate that S2EBPR can achieve effective phosphorus removal from carbon-limited wastewaters without external supplementation.

In order to rapidly prepare the filter media loaded with manganese oxide membrane, zeolite modified with sodium dodecyl sulfate (SLS) solution was used as the carrier, and the membrane hanging solution was used to rapidly load the manganese oxide membrane on the modified zeolite filter column, and the effects of the initial concentration and filtration rate on the effect of the column on the removal of NH4+ and Mn2+ were investigated. The results showed that 200mg/L Mn2+ solution and 0.01 mol/L KMnO4 solution were periodically run to dynamically load the membrane on the column, and the membrane was successfully loaded on the 7th day, and the concentrations of NH4+ and Mn2+ in the effluent water were 0.199 mg/L and 0.066 mg/L, which were lower than the limit values of NH4+ and Mn2+ in the "Hygiene Standard for Drinking Water" (GB 5749－2022). The removal rate of Mn2+ was 98.4%～96.7% when the concentration of NH4+ inlet water was 2 mg/L, and 49.5% when the concentration of NH4+ inlet water was 3～8 mg/L. The removal rate of Mn2+ was 97.6%～89.5% when the concentration of Mn2+ inlet water was 1～8 mg/L. The inhibition effect of initial concentration of NH4+ on the removal of Mn2+ was significant, and the removal rate of Mn2+ was 0.066, 0.199, 0.066 mg/L, which was lower than that of NH4+ and Mn2+ in GB 5749－2022. The initial concentration of NH4+ had a significant inhibitory effect on the removal of Mn2+, and the initial concentration of Mn2+ had no effect on the removal of NH4+. The effluent NH4+ and Mn2+ concentrations were 0.25 mg/L and 0.088 mg/L, respectively, when the controlled filtration rate was 4 m/h. By comprehensive characterization of natural zeolite, modified zeolite, and membrane-hanging zeolite, the results showed that the modification of the natural zeolite by SLS was successful in improving the adsorption effect of the zeolite on Mn2+, and realizing a large amount of accumulation of Mn2+ on the surface of the zeolite. The main components of the manganese oxide film are Mn3O4 and MnO2, which have oxidizing effects on NH4+ and Mn2+.

A pilot study was conducted on a seawater desalination system using an air flotation–ultrafiltration–reverse osmosis process to address operational challenges posed by fluctuations in inlet water temperature. During the field test, the seawater temperature increased gradually from 3 ℃ to 13 ℃, and the average turbidity of the raw seawater inlet was approximately 7 NTU. The results showed that the turbidity of the air-flotation effluent remained below 3 NTU, while the turbidity of the ultrafiltration effluent was maintained below 0.3 NTU, indicating stable performance of the pretreatment system. Operating at a recovery rate of 40%, the reverse osmosis membrane flux rose from 8.9 L/(m2·h) to 14.7 L/(m2·h), and the system operated steadily as the inlet pressure decreased with rising temperature.

Comprehensive electroplating wastewater from an electronics manufacturer in Suzhou routinely exceeds discharge limits for chemical oxygen demand (COD) and heavy metals. This study assessed a micellar-enhanced coagulation–sedimentation process that uses sodium alkyl ether carboxylate–polymeric aluminium ferric sulfate (AEC-PAFS) as the coagulant. Bench-scale tests were performed to determine the effects of AEC mass fraction in the composite coagulant, overall dosage, initial pH and coagulation time on treatment performance. Optimum conditions were obtained at an AEC mass fraction of 0.30%, an AEC-PAFS dosage of 120 mg/L, an initial pH of 9~10 and a coagulation time of 2.5 h. Under these parameters, the removals of COD, suspended solids (SS), Cd, Pb, Zn, Ni, Cu, Hg and Cr were 63.2%, 89.5%, 79.7%, 77.1%, 75.2%, 70.5%, 65.4%, 60.8% and 35.6%, respectively. The optimised process was then incorporated into the existing treatment train during a pilot-scale trial at the plant. Effluent concentrations of COD, SS and all eight regulated heavy metals complied with the limits in Table 3 of the Chinese standard GB 21900-2008, demonstrating the feasibility of AEC-PAFS micellar-enhanced coagulation–sedimentation for advanced treatment of comprehensive electroplating wastewater.

This study evaluated the impact of ibuprofen (IBP) on nitrogen and phosphorus removal in a novel anaerobic/oxic/anoxic (AOA) system operated at 10–15 °C with influent IBP concentrations of 0–6 mg/L. Reactor performance, sludge properties, microbial activity, and community composition were monitored to elucidate the underlying mechanisms. Increasing IBP concentrations progressively impaired pollutant and nutrient removal. IBP exposure decreased mixed-liquor suspended solids, organic content, and sludge settleability, but markedly increased extracellular polymeric substances (EPS); at 6 mg/L, total EPS, protein, and polysaccharide contents reached 95.8～99.7, 64.5～66.1, and 31.4～34.2 mg/g, respectively. The specific oxygen uptake rate fell to 34.2 mg/(g·VSS·h), whereas reactive oxygen species and lactate dehydrogenase activities rose, indicating oxidative stress and diminished metabolic activity. High IBP levels also reduced the relative abundances of Proteobacteria and Acidobacteriota. These findings improve understanding of IBP behaviour in low-temperature wastewater and provide guidance for sustaining efficient nutrient removal in AOA systems.

The design and treatment scale of sewage treatment project in an industrial agglomeration area is 3.0×104 m3/d. In view of the characteristics of high proportion of industrial wastewater, large impact load of water quantity and water quality and high requirement of effluent quality, the biochemical treatment system adopts "A2O+MBR" treatment process, which strengthens the biodegradation and achieves the goal of nitrogen and phosphorus removal, thus meeting the requirements of pollutant discharge in the Yellow River Basin of Henan Province. The process design parameters of the main treatment structures are introduced, which can be used for reference by relevant designers.

The original design scale of a municipal sewage treatment plant in Sichuan was 10×104 m3/d, and the effluent complied with the First-Level A discharge standard of GB 18918－2002. The main process used an improved DE oxidation ditch. Practice has shown that the operation of the factory cannot meet the standard stably and has limited potential for improvement. With the increasing environmental requirements, it is now necessary to meet the discharge requirements of urban sewage treatment plants in the "Water Pollutant Discharge Standards for Minjiang and Tuojiang River basins in Sichuan Province" (DB 51/2311－2016). Through the analysis of the original process and operational practice, the measure of transforming the DE oxidation ditch into a multi-stage AO and adding a deep treatment process is adopted, that is, upgrading the oxidation ditch into a multi-stage AO + secondary sedimentation tank + denitrification filter + sodium hypochlorite disinfection standard process. The results showed that when the average COD, TN, and TP of the influent were 258, 41.8 and 3.8 mg/L, the treated effluent decreased to 14.8, 7.2 and 0.1 mg/L, with corresponding removal rates of 94%, 83%, and 97%, respectively. The effluent met the new standard requirements. This technical renovation project fully utilized the original structure, with low investment, land saving, and high treatment efficiency, which can be used as a reference for similar wastewater treatment plants to improve standards and operate.

The design treatment scale of phase I project of a WWTP in Huizhou City is 1.0×104 m3/d, the "A/A/O oxidation ditch +high efficiency sedimentation tank + rotary fibre-plate filter" treatment process was adopted. Due to increased discharge of domestic sewage, the treatment capacity of the phase II expansion project was 2.0×104 m3/d and the phase I project was reconstructed in 2020, the main treatment process was UCT+high efficiency sedimentation tank + Rotary microfilter. The operation results showed that the eflluent quality stably met the stricter values of discharge standard of water pollutants in watershed of DanShui River and ShiMa River (DB 44/2050－2017) and of first level A criteria in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918－2002) in 2023, the average annual removal rate of CODcr, BOD5, SS, NH3-N, TN and TP increased by 4.87%, 5.93%, 1.87%, 0.67%, 7.97% and 2.27% compared with 2019, respectively.