10 September 2026, Volume 52 Issue 9
    

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  • LIU Yiqing, CHEN Zhengjie, YANG Zhongyi, CHEN Chuanzeng, HU Hong, JI Yang
    Technology of Water Treatment. 2026, 52(9): 1-5.
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    Tunnel engineering constitutes an indispensable component of railway construction, with substantial volumes of construction wastewater generated throughout its construction process. This study analyzes the sources, pollutant types, and hazards of railway tunnel construction wastewater, while also summarizing the research status of its treatment technologies. Furthermore, it systematically sorts out the sources of inorganic particles in such wastewater and reviews the current research on the characteristics of these inorganic particles and their influencing factors. Finally, this study prospects the development trends of research on both tunnel construction wastewater treatment technologies and the characteristics of inorganic particles.
  • LI Zhaozhao, SUN Haiquan, YAO Guozhu, WANG Xuejiao, XUZhaohong, BI Dongmei
    Technology of Water Treatment. 2026, 52(9): 6-12.
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    Due to the increasing discharge of industrial wastewater and domestic sewage, refractory organic pollutants pose a serious threat to the safety of water environment. Biochar has shown unique advantages in the field of organic pollutant removal due to its wide source of raw materials, low cost and adjustable structure and performance by modification. In this manuscript, the latest research progress on the removal of organic pollutants by modified biochar, from three dimensions: physical structure modification, surface functionalization single modification, and composite modification strategies are systematically reviewed. It sorts out the regulation effects of different modification methods on the specific surface area, pore structure, and surface functional groups of biochar. It deeply analyzes its removal mechanism, including the adsorption mechanism of physical and chemical synergy, as well as the catalytic degradation mechanism of activating H2O2 and activating persulfate. This article integrates innovative research results from various fields, clarifies the adaptability and synergy of different modification strategies, and provides theoretical support and technical reference for the design and optimization of efficient biochar-based materials and the treatment of refractory organic pollutants in water environments.
  • ZHANG Yuliang, XIE Wenyu, WANG Qinghong, LIANG Jiahao, CHEN Kaiping, LI Changgang
    Technology of Water Treatment. 2026, 52(9): 13-19.
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    Anaerobic digestion (AD) is a promising biological treatment technology enabling the simultaneous removal of pollutants and recovery of resources from sulfate-containing organic wastewater. However, under sulfate-rich conditions, competition for substrates between sulfate-reducing bacteria (SRB) and methanogens, coupled with the toxic inhibition of sulfides (a metabolic product of SRB) on methanogens, frequently impairs system stability and reduces methane production efficiency. This poses a critical constraint on the engineering-scale application of AD for such wastewater. This review systematically summarizes the key inhibitory mechanisms of sulfate on the anaerobic digestion process and provides a comprehensive overview of recently developed strategies for enhancing process performance. These strategies include pH regulation, optimization of the COD/SO42- ratio, establishment of two-phase anaerobic systems, supplementation with functional materials and chemical additives, incorporation of bioelectrochemical systems, and coupling to photosynthetic bacteria. Furthermore, the limitations of existing research are critically analyzed, and future perspectives are put forward to guide the optimization and practical implementation of AD for sulfate-containing organic wastewater.
  • REN Yuantao, LIU Cao, WANG Min, WU Kehong, WU Yang
    Technology of Water Treatment. 2026, 52(9): 20-27.
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    The advanced purification of effluent from wastewater treatment plants (WWTPs) and the safe disposal of excess sludge have become critical bottlenecks in achieving water resource recycling. To address this integrated "sludge-water co-treatment" challenge, a green technological pathway has been developed in which sludge is valorized into ceramsite fillers for application in constructed wetland systems, embodying a "waste-treats-waste" philosophy. This review systematically examines the core components of this technological framework: the preparation principles and performance characteristics of sludge-based ceramsite (encompassing bloated, sintered, and non-fired types) are elaborated; the pollutant purification mechanisms of ceramsite-filled constructed wetlands, which involve the synergistic functions of physical filtration, chemical adsorption (particularly phosphorus removal via Fe/Al and nitrogen removal through ion exchange), and biofilm carrier activity, are analyzed in depth; and the removal efficiencies and applicable conditions of various sludge-ceramsite wetland systems for nitrogen, phosphorus, and organic matter in practical effluent treatment are comprehensively evaluated. Future research priorities are also identified, with emphasis on optimizing preparation processes to reduce energy consumption, strengthening long-term risk control for heavy metals and other contaminants, and exploring enhanced removal mechanisms for emerging pollutants. This review aims to provide a robust theoretical foundation and practical technical guidance for advancing integrated sludge-water co-treatment in WWTPs.
  • GUO Xuanyin, YE Fan
    Technology of Water Treatment. 2026, 52(9): 28-34.
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    Increasing water scarcity, the growing complexity of industrial wastewater, and the implementation of carbon peaking and carbon neutrality targets have imposed higher requirements on conventional water treatment technologies. Traditional treatment strategies, which mainly focus on endof- pipe discharge compliance, show obvious limitations in terms of energy consumption, chemical use, carbon emissions, brine disposal, and resource recovery, and therefore can no longer fully meet the demands of green and low-carbon industrial water treatment. This review summarizes recent advances in low-carbon and energy-saving technologies for water treatment, with particular emphasis on the principles, application scenarios, and development characteristics of low-energy membrane separation, high-efficiency electrochemical technologies, and bio-enhanced green treatment processes. Overall, future water treatment technologies should shift from single-pollutant removal toward the coordinated optimization of water, energy, carbon, and resource flows. Further efforts are needed to address key challenges related to multi-technology integration, process stability, resource utilization, and engineering-scale application, thereby providing technical support for the low-carbon treatment of industrial wastewater.
  • HU Qili, GONG Jie, LI Yulong, LIU Hengyuan, LI Ruizhen, MEI Changgen
    Technology of Water Treatment. 2026, 52(9): 35-45.
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    Faced with the challenges of low phosphate removal efficiency and adsorbent agglomeration in eutrophic water remediation, this study developed iron/cerium-modified chitosan beads (Fe/Ce-CB) via a coprecipitation method. The effects of adsorbent dosage, initial solution pH, and coexisting ions on phosphate adsorption performance were systematically investigated. Adsorption kinetics, equilibrium characteristics, and surface energy distribution were analyzed using kinetic models, isotherm models, and site energy distribution theory, respectively, while the underlying removal mechanisms were elucidated through multiple characterization techniques. The results demonstrated that Fe/Ce-CB possessed a wrinkled surface and mesoporous structure with a specific surface area of 6.26 m2/g. The synergistic effects of Fe (4.9 wt%) and Ce (13.4 wt%) provided abundant adsorption sites. The adsorption process followed the pseudo-nth-order kinetic model (Adj. R2 = 0.997 6), with intraparticle diffusion identified as the rate-limiting step. The Dubinin-Radushkevich model predicted a maximum adsorption capacity of 83.5 mg/g. Lower initial pH values enhanced phosphate removal due to increased electrostatic attraction, whereas SO42- was the only coexisting ion that caused notable interference, indicating high selectivity of Fe/Ce-CB. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed that phosphate adsorption occurred via chemical bonding between phosphate ions and surface hydroxyl groups through Fe/Ce-O-P coordination. The granulated design of Fe/Ce-CB effectively overcame the agglomeration limitations inherent to conventional powdered adsorbents, demonstrating strong potential for practical engineering applications.
  • ZHOU Aixin, SONG Hang, CHONG Guangsen, ZHANG Yong, LI Kuiling, WANG Jun
    Technology of Water Treatment. 2026, 52(9): 46-52.
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    Membrane separation technology offers the advantage of high removal efficiency in treating oily wastewater. However, tiny oil droplets are highly prone to adhering to the membrane surface, leading to severe membrane fouling. Enhancing the surface roughness and hydrophilicity of membranes by loading micro-nano particles is an effective approach to alleviate membrane fouling. Nevertheless, there are few reports on the effect of the size of loaded particles on the anti-fouling performance of modified membranes. In this study, a series of silica (SiO2) microspheres with different particle sizes were prepared by coupling the Stöber method with a multi-step seed growth method. By optimizing the concentrations of tetraethyl orthosilicate (TEOS) and ammonia, as well as the amount of seed added, the SiO2 microspheres achieved uniform and controllable particle sizes in the range of 0.36 μm to 2.10 μm. Four types of SiO2 microspheres with different particle sizes were selected and loaded onto the surface of polyvinylidene fluoride (PVDF) membranes to prepare hydrophilic-oleophobic SiO2/PVDF membranes (abbreviated as SP membranes). Among these modified membranes, the one modified with SiO2 microspheres of 1.08 μm particle size showed the best permeation and anti-fouling performance when treating oil-in-water emulsions. Under operating conditions of 0.7 bar and a backwashing pressure of 0.3 bar, its normalized flux and flux recovery rate reached over 15% and 95%, respectively. This study provides an important basis for the preparation of micro-nano particle-modified membranes for oil-water separation.
  • MO Shucheng, LI Tianyu, SUN Nan, CAI Yuanhang, LI Xiaoming, WANG Jian, HE Tao
    Technology of Water Treatment. 2026, 52(9): 53-58.
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    Hollow-fiber ultrafiltration (UF) and microfiltration (MF) membranes are mature separation materials for water treatment. Their permeation performance has been markedly enhanced by recent technological advances. Accurate evaluation is therefore essential. Guided by the national standards GB/T 32360–2015 for UF and HY/T 051–1999 for MF, this research systematically examined factors affecting pure-water permeance (PWP) measurements, including transmembrane pressure (TMP), fiber length and count, compaction, and filtration mode (dead-end or crossflow). The results indicated that the conventional dead-end measurement underestimated PWP for high-permeance membranes because the standards use inlet pressure as the TMP and ignore the pressure drop along the fiber. Using the average of inlet and outlet pressures to calculate the TMP improved measurement accuracy. Under dead-end conditions, the pressure drop is proportional to fiber length, leading to large differences in results for different fiber lengths. The number of fibers had no significant impact on PWP values, and no membrane compaction was observed. Overall, crossflow operation provided more accurate PWP measurements for high-performance hollow-fiber membranes than dead-end testing. Our work provides a new methodology for the accurate measurement of high-permeance hollow-fiber UF and MF membranes.
  • WANG Xiquan, LYU Yanli, SONG Xihui, CHEN Shuyi, WANG Kexin, CHENG Pengfei
    Technology of Water Treatment. 2026, 52(9): 59-66.
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    The morphology control and non-metallic doping were used to control the band gap structure,the three-dimensional flower-like Bi2WO6 and KI-Bi2WO6 doped photocatalytic materials were developed by using the surfactant PVP K30 and KI. The morphology, chemical composition,optical properties and photocatalytic performance was investigated. On this basis, the photocatalytic performance and catalytic mechanism of the composite catalyst were studied by taking Rhodanine B (RhB) as the degradation object. The results showed that KI-Bi2WO6 magnetic composite catalyst exhibited excellent catalytic degradation performance for RhB under visible light irradiation. When the initial concentration of RhB is 10 mg/L, the dosage concentration of catalyst is 2.0 g/L, and the initial pH value of RhB is 7, the decolorization rate reached 97%. After multiple recovery and use, the composite catalyst still had a high degradation effect on RhB, and the catalyst had excellent chemical stability. The free radical trapping experiments demonstrate that in the photocatalytic degradation of RhB by the composite catalyst, holes and electrons play a dominant role, followed by hydroxyl radicals and superoxide radicals.
  • CAI Jiehui, PAN Huafeng, HUANG Zhengqin, YANG Yingquan, LI Hailiang
    Technology of Water Treatment. 2026, 52(9): 67-72.
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    Using bagasse as raw material, activated carbon was prepared by soaking in sodium hydroxide solution and sintering at high temperature. CTMAB modified bagasse activated carbon (CTMAB-NaBC) was prepared by modifying activated carbon with cetyltrimethylammonium bromide(CTMAB). The CTMAB-NaBC's capacity to remove congo red(CR) from aqueous solution was evaluated and the adsorption mechanism elucidated. Under optimal conditions (CR concentration, 800 mg/L; sorbent dosage, 0.25 g/L; pH,7;318 K; 60 min), the maximum adsorption capacity reached 3 194.61 mg/g. After four adsorption-desorption cycles, the CTMAB-NaBC retained 82.96% of its initial capacity. The adsorption of CR by CTMAB-NaBC conformed to the pseudo-second-order kinetic model. The adsorption process was dominated by chemical adsorption and supplemented by physical adsorption. SEM results showed that the surface of CTMAB-NaBC was rough and had a certain pore structure. BET results showed that CTMAB-NaBC had rich mesoporous structure. XRD results showed that CTMAB-NaBC had a stable crystal structure after adsorption of CR. TGA results showed that CTMAB-NaBC had certain thermal stability after adsorption of CR. The experimental results showed that CTMAB-NaBC successfully adsorbed CR, which provideed a new idea for the treatment of organic dye wastewater.
  • KANG Gang, ZHANG Lucheng, XU Zihui, LI Rong, ZHANG Mingqing, CHENG Wei
    Technology of Water Treatment. 2026, 52(9): 73-80.
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    Porous carbon spheres (NaOH-PCS) were synthesized via a combination of hydrothermal treatment, high-temperature carbonization, and NaOH activation, using sucrose and poly(vinyl alcohol) (PVA) as precursors. Their adsorption performance toward norfloxacin (NOR) in aqueous solutions was systematically evaluated. The physicochemical properties of NaOH-PCS were characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption (BET) analysis. The results demonstrated that NaOH-PCS exhibits a porous spherical structure with a rough surface, a specific surface area of 258.77 m2/g, and a pore size distribution dominated by micropores (0.4~2 nm). Adsorption kinetic analysis revealed that the process followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism. Adsorption isotherm fitting demonstrated that the Freundlich model provided the best correlation, with a maximum theoretical adsorption capacity of 82.24 mg/g Thermodynamic parameters (ΔG0 < 0, ΔH0 > 0, ΔS0 > 0) revealed that the adsorption process is spontaneous, endothermic, and entropy-increasing. NaOH activation significantly enhanced the adsorption performance of the porous carbon spheres, providing both a novel adsorbent material and a promising solution for the remediation of antibiotic-contaminated water.
  • SHAO Wei, MENG Duo, YANG Hehe
    Technology of Water Treatment. 2026, 52(9): 81-88.
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    To enhance the adsorption capacity of sludge-derived biochar for heavy metals in aqueous environments, this study prepared biomass-sludge mixed biochar (O-SBC) via co-pyrolysis of orange peel and municipal sludge, and explored the optimal preparation parameters. It systematically investigated the adsorption performance and mechanisms of O-SBC for Pb2+ and Cd2+. Experimental results showed that O-SBC exhibited the highest adsorption capacity for Pb2+ under the optimal preparation parameters (pyrolysis temperature: 700 ℃, pyrolysis time: 4 h, orange peel addition ratio: 20%). In contrast, the optimal parameters for Cd2+ adsorption were 700 °C, 4 h, and 40% orange peel addition ratio. After incorporating orange peel, the specific surface area of O-SBC was approximately twice that of pristine sludge-derived biochar (SBC), and the pore volume increased by 27%. The effects of reaction parameters on the adsorption of Pb2+ and Cd2+ showed similar trends. The optimal adsorption parameters were as follows: solid-liquid ratio of 2.5 g/L, initial solution concentration of 100 mg/L, pH 6, and contact time of 6 h. The adsorption processes of O-SBC for Pb2+ and Cd2+ both fitted well with the pseudo-second-order kinetic model; the adsorption isotherms of Pb2+ and Cd2+ were well described by the Langmuir model and Freundlich model, respectively. Mechanistic investigations indicated that the adsorption process involved multiple pathways, including chemical complexation, ion exchange, and pore filling. Among these, the surface functional groups of O-SBC dominated the adsorption process via complexation. Under competitive adsorption conditions, Pb2+ exhibited a competitive advantage over Cd2+ owing to its smaller hydration radius, and thus preferentially occupied the active adsorption sites.
  • LI Jiacheng, HE Dedong, CHEN Dingkai, LUO Yongming, CAO Xiaohua
    Technology of Water Treatment. 2026, 52(9): 89-94.
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    This study, targeting the combined pollution characteristics of high turbidity, high phosphate, and high fluoride in yellow phosphorus wastewater, constructed a combined flocculation-adsorption system of poly-silicic ferric calcium lanthanum (PSFCL) and hydroxyapatite (HAP), coupled with in-situ oxidation of ferrous ions (Fe2+) for advanced treatment. At pH 5, the synergistic effect of PSFCL and HAP achieved removal efficiencies of 98.48%, 97.03%, and 93.24% for phosphate, fluoride, and turbidity, respectively, which were 2.95, 2.2, and 2.56 times higher than those of HAP alone. This enhancement is attributed to the proton neutralization between OH- released from HAP via ligand exchange and free Fe3+ ions, which optimized the flocculation microenvironment. Crucially, the subsequent addition of Fe2+ generated Fe3+ in situ via slow oxidation, and the unique edge-sharing and corner-sharing Fe coordination structures facilitated inner-sphere complexation with phosphate, significantly inhibiting the self-desorption of phosphate from flocs. As a result, the phosphate removal rate increased to 99.45%, and the phosphorus fixation duration was extended from 24 h to 48 h. This study demonstrates that the combination with Fe2+ is not merely a supplementary step, but fundamentally enhances phosphorus removal efficiency and solid-phase stability by modulating the formation pathway of iron species and the coordination condition, thereby providing an efficient and stable technical approach for the advanced purification of yellow phosphorus wastewater.
  • XU Lei, CHAI Guang, WU Wei
    Technology of Water Treatment. 2026, 52(9): 95-100.
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    The sludge/cotton stalk biochar composite (SBC) was prepared by pyrolysis at 600 °C under limited oxygen conditions, using agricultural waste cotton stalks and residual sludge treated with garbage leachate as precursor materials. Characterization analyses, including BET, FTIR, and Raman spectroscopy, revealed that co-pyrolysis markedly enhanced the specific surface area, density of surface oxygen-containing functional group, and the degree of structural defect in SBC. A visible light (Vis) system coupled with peroxymonosulfate (PMS) was developed using SBC as a catalyst for the degradation of triclosan (TCS) in water. The experimental results showed that the synergistic system achieved a significantly higher TCS degradation rate (92%) and reaction rate constant (0.982 0×10-2 min-1) compared to the individual SBC/PMS and SBC/Vis systems. Mechanistic investigation shown that TCS degradation was synergistically driven by both radical pathways (•OH, SO4•-, h+, and O2•-) and non-radical pathways (1O2). After five consecutive cycles, the TCS degradation rate remained above 84%, underscoring the excellent catalytic stability of the SBC. These research findings provide a theoretical foundation for the development of green and sustainable catalytic systems.
  • QIN Weiwei, WANG Wei, KANG Siyuan, LI Yuheng, HUAN Xi, ZHU Hangke
    Technology of Water Treatment. 2026, 52(9): 101-105.
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    With the increasingly serious problem of global freshwater shortage and the rapid consumption of fossil energy, the development of a sustainable, environmentally friendly and efficient freshwater production technology has become a hot research topic. Solar interfacial evaporation technology has become one of the important research directions to solve the freshwater shortage due to its advantages of high efficiency, low energy consumption and green environment. Herein, a porous carbon evaporator with 3D vertical water channels was designed and prepared by artificially opening holes by using potato as the raw material of biomass carbon material. The evaporator incorporated a natural honeycomb pore structure that effectively improved the material's water transport path and heat distribution at the evaporation interface. The results showed that the evaporation rate of the material under 1 kW/m2 was 1.43 kg/(m2·h) with a conversion efficiency of 97%, which was significantly better than that of the carbon material without open-pore treatment. In addition, the material still maintained an evaporation rate of 1.13 kg/(m2·h) and a conversion efficiency of 83.8% after continuous evaporation in 20% NaCl high-salt solution for 6 h. This result indicates that the design of the three-dimensional water channels effectively retarded the accumulation of salt ions, and maintained a better evaporation stability and salt resistance performance.
  • XING Dongbo, DU Fawang, QI Xueling
    Technology of Water Treatment. 2026, 52(9): 106-110.
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    Superhydrophobic/superoleophilic materials exhibit significant advantages in the separation of water-in-oil (W/O) emulsions owing to their unique surface wettability. This study employed three silane coupling agents with different alkyl chain lengths—dodecyltrimethoxysilane (DTMS), hexadecyltrimethoxysilane (HDTMS), and octadecyltrichlorosilane (OTS)—to modify the surface of quartz sand (QS), successfully fabricating gradient hydrophobic modified quartz sand materials (DTMS-QS, HDTMS-QS, and OTS-QS). Experimental results demonstrated that the water contact angle (WCA) of the modified materials increased from 47.5° (pristine quartz sand) to 148.2°, 152.4°, and 156.6°, respectively, while the oil contact angle (OCA) of all modified materials was close to 0°, indicating typical superhydrophobic/superoleophilic characteristics. Among them, OTS-QS exhibited the optimal hydrophobic performance and was thus selected as the research object for subsequent W/O emulsion separation. When applied to the separation of different W/O emulsions, OTS-QS showed excellent separation performance: the separation efficiency was consistently maintained at a high level of 98.34%~99.76%, while a stable oil flux of 1 547.13~2 062.55 L/(m2·h) was retained. The surface modification method developed in this study is simple and efficient, providing a novel strategy for the development of high-performance particle-based oil-water separation materials.
  • WANG Zhibo, CHEN Nan, WANG Tiantian, WANG Xiaodong, FENG Chuanping
    Technology of Water Treatment. 2026, 52(9): 111-117.
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    Based on the screening of hydroxyiron oxide (HFO) as a superior arsenic-removing adsorbent, iron oxyhydroxide-calcium alginate composite beads (IACB) were prepared via embedding. On the basis of influence factor experiments, kinetic experiments, and thermodynamic experiments, continuous flow experiments were conducted to predict the As breakthrough curve, explore the dynamic adsorption capacity of the material, and analyze the dynamic adsorption kinetics through mathematical model fitting. Under three different influent flow rates (1.5, 2.0, and 2.5 mL/min), the Thomas model predicted that the equilibrium dynamic adsorption capacities of IACB for arsenic in mine water were 13.876, 15.810, and 12.712 mg/g, respectively. The Yoon-Nelson model predicted that the times corresponding to the 50% breakthrough point were 91, 78, and 67 days, respectively. The fitting results of the Adams-Bohart model indicated that the adsorption removal rate was not proportional to the remaining capacity of the adsorbent and the concentration of the adsorbate. Furthermore, the reaction mechanism between IACB and arsenic in mine water during the continuous flow experiments was revealed through characterization analysis. Studies demonstrated that the static or continuous flow adsorption performance of IACB was superior to that of materials such as activated alumina, modified sepiolite, and modified activated carbon. IACB not only solves the defects of HFO in practical application but also possesses the advantages of high dynamic adsorption capacity and long-term service life, thereby exhibiting good application prospects in the field of mine water arsenic pollution control.
  • LU Fan, PAN Wenxiu, BAI Wenke, ZHANG Kangkang, ZHAO Jianbo, YANG Zhen
    Technology of Water Treatment. 2026, 52(9): 118-125.
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    This study addressed the high colority and toxicity of textile dyeing wastewater by developing a novel, efficient, and cost-effective composite flocculant. The material was synthesized through interface-controlled chemical bonding involving dicyandiamide, formaldehyde, ammonium chloride, urea, and polyaluminum chloride (PAC), resulting in, for the first time, a molecular-level composite of Dicyandiamide-Formaldehyde-Coated (DFC) and PAC. A synergistic "electrostatic neutralization-coordination complexation" mechanism was demonstrated. Response surface methodology was employed to optimize the conditions, which indicated that a PAC mass fraction of 62%, reaction temperature of 73 ℃, and reaction time of 2.5 h favored the selective binding of C2N+ and Al3+ to sulfonate groups (-SO3-) and hydroxyl groups on dyes, respectively. This led to a significant enhancement of the floc structure, evidenced by a 16.47% increase in viscosity, and an improved decolorization efficiency that exceeded that of conventional physical mixing methods by 12.58%. Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed that the synergistic removal mechanism involved electrostatic neutralization by C2N+ functional groups and coordination interactions with Al3+, which strengthened the floc integrity through combined electrostatic and complexation effects. In practical wastewater treatment applications, the composite flocculant achieved removal rates of 98.23% for color and 77.49% for COD without pH adjustment, with the treatment cost reduced to only 0.53 yuan per ton of water, demonstrating a higher cost-performance ratio and greater application potential compared to single flocculants such as PAC and DFC. This work provided a theoretical foundation and practical methodology for the high-efficiency, low-cost treatment of textile dyeing wastewater, thereby contributing to sustainable water environment management and supporting the goals of "clean water" and environmental protection.
  • WANG Fan, ZHANG Fangyuan, REN Qingkai, SUN Jialu, WU Ji, BIAN Dejun
    Technology of Water Treatment. 2026, 52(9): 126-131.
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    To address the needs of reducing energy consumption and improving treatment efficiency in township sewage treatment, this study constructed a micro-pressure integrated biological treatment reactor. The research focused on investigating the removal efficiencies of chemical oxygen demand (COD) and nitrogen (N), the performance of synchronous nitrification and denitrification (SND), and the dynamic changes in the microbial community structure of the reactor under continuous flow operation—with the goal of establishing a stable SND nitrogen removal system. Experimental results showed that the integrated reactor achieved over 90% removal efficiency for both COD and ammonia nitrogen (NH4+-N), and a total nitrogen (TN) removal efficiency of 60%. The dissolved oxygen (DO) concentration across all reactor stages ranged from 1.2 to 1.8 mg/L, and the activated sludge particle size increased significantly. At this stage, functional bacteria were enriched, including Saccharimonadales (with anaerobic denitrification capacity) and Flavobacterium (with aerobic denitrification capacity). Concurrently, the aerobic nitrification rate increased progressively, and SND tests confirmed that the SND rate reached 30%. The coexistence and synergistic growth of these multi-functional bacteria collectively promoted the SND nitrogen removal process in the reactor.
  • LIU Jiajun, GU Jiayan, HE Guofu, SUN Zihuan, ZHAO Xiaoqi, CAI Jingli
    Technology of Water Treatment. 2026, 52(9): 132-140.
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    Considering the characteristics of relatively low pollutant concentrations in rural greywater under the black-grey separation mode—facilitating treatment and resource recovery—and to explore the feasibility and optimal operating conditions of biofilm-based rural greywater treatment, this study used domestic greywater from a village in the Yangtze River Delta as the research subject. Fillers including polyurethane, braided belts, and ceramsite were selected to construct a greywater treatment unit, and the effects of different fillers, hydraulic retention time (HRT), and filling ratios on greywater treatment performance were investigated. Experimental results demonstrated the following: 1) Polyurethane sponge fillers exhibited significant advantages. At the biofilm maturation stage, the average removal rates of CODcr, NH3-N, TN, and TP reached 76.6%, 54.4%, 55.5%, and 35.5%, respectively, which were significantly superior to those of other fillers (p<0.05); 2) When the HRT was 8 h, the polyurethane sponge filler showed optimal hydraulic shock load resistance; 3) A 45% filling ratio achieved the best synergistic effect among the filler, microorganisms, and hydraulic conditions; 4) The polyurethane sponge filler with a 45% filling ratio achieved the optimal comprehensive treatment performance. Under these optimal conditions, the effluent met the water quality requirements for urban greening, road cleaning, construction, and other uses specified in Reuse of Urban Reclaimed Water—Water Quality for Urban Miscellaneous Water Consumption (GB/T 18920–2020) after disinfection. High-throughput sequencing was performed to analyze the microbial community composition of different fillers, revealing high microbial diversity across all filler types. The dominant phyla in the system were Proteobacteria and Firmicutes, while the dominant genera were Rhodopseudomonas and Desulfovibrio. This indicates that the biofilm method can effectively remove organic matter, nitrogen, and phosphorus. This study provides technical support for the decentralized treatment of rural greywater, facilitates the standardized application of the black-grey separation mode and closed-loop resource management, and offers a practical reference for improving the rural living environment and advancing ecological revitalization.
  • DING Ying, XIA Qing, XU Xiangdong, ZHOU Chuanting, ZHOU Zhen
    Technology of Water Treatment. 2026, 52(9): 141-146.
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    The removal and recovery of ammonia nitrogen (NH4+-N) from high NH4+-N wastewater was performed utilizing a deamination membrane process. The results showed that when the pH of the wastewater was controlled at 11, the concentration of H2SO4 in the absorption liquid was 0.064 9 mol/L, the membrane surface flow rate of the absorption liquid was 2.17×10-2 m/s, the reaction temperature was 25 ℃, and the membrane surface flow rate of the wastewater was 3.62×10-3 m/s, the ammonia removal rate could reach 94.4% under the condition of 500 mg/L NH4+ concentration in the wastewater. Under optimal conditions, utilization of 30% H2SO4 as the absorption liquid yielded an ammonium sulfate solution concentration of 12%. To obtain solid ammonium sulfate exceeding 98% purity, subsequent concentration and crystallization were necessitated. At a treatment capacity of 200 m3/d, the operating cost of the deamination membrane process was calculated to be 7.24 yuan/m3, with a product revenue of 1.60 yuan/m3.
  • LIU Mengting, ZHANG Feihu, LOU Qian, HE Tao, JIAN Minfei, DING Huijun
    Technology of Water Treatment. 2026, 52(9): 147-153.
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    As a natural adsorption material,red soil has obvious advantages of wide source and low cost,and has broad application prospects for antibiotic removal in water environment.In this study,adsorption-desorption of vancomycin (VAN) from wastewater on red soil was investigated in a batch system. The influencing factors of the adsorption of vancomycin were analyzed, and the adsorption mechanism was explored by kinetic and isothermal adsorption models. Besides, the response characteristics of this method in actual wastewater were investigated. Results showed that the adsorption efficiency increases first and then becomes stable with the increase of red soil concentration.The optimal concentration of red soil is 20 g/L.The higher pH lead to increased adsorption efficiency, and the maximum adsorption rate was 98.09%.With the increase of coexisting ion concentration, the adsorption rate showed an obvious downward trend,and the inhibition effect of Ca2+ was the strongest.The good fitting of both pseudo-first-order and pseudo-second-order kinetic models indicates that the adsorption process in red soil is jointly controlled by physical and chemical reactions. Both Freundlich model and Langmuir model are suitable for describing the adsorption characteristics of vancomycin in red soil,indicating that multimolecular layer adsorption and single-molecular layer adsorption exist simultaneously,and the theoretical maximum adsorption capacity is 9.22 mg/g.The response characteristics of this method in actual wastewater are manifested as achieving a good removal effect after prolonging the reaction time.In the pilot-scale system,the adsorption rate is 81.21% after 6 h.This research can provide a reliable solution for the removal of vancomycin in the environment.
  • GAO Qian, XIAO Junyan, YANG Yanbing, XU Xintao, ZHU Xuewu
    Technology of Water Treatment. 2026, 52(9): 154-160.
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    To address the well-recognized permeability-selectivity trade-off in polyamide (PA) nanofiltration (NF) membranes for practical applications, this study proposes an interfacial polymerization (IP) strategy combined with acid-assisted thermal etching as a post-treatment regulation approach for fabricating a series of structurally tunable, high-performance NF membranes. The results demonstrate that acid thermal treatment effectively etches the PA selective layer, reducing its crosslinking degree and leading to a more open pore structure, while simultaneously promoting the formation and exposure of oxygen-containing functional groups—thereby significantly enhancing membrane surface hydrophilicity and negative charge density. With increasing post-treatment intensity, membrane permeability increased progressively. Among the membranes evaluated, the optimized NF-3 membrane achieved the best balance between permeability and selectivity, exhibiting a pure water permeability of 16.7 L/(m2·h·bar) during natural surface water filtration while maintaining a Na2SO4 rejection of 98.35%. In natural surface water purification experiments, NF-3 demonstrated excellent removal of dissolved organic matter, with TOC and UV254 rejection rates of 86.35% and 88.27%, respectively. In addition, NF-3 exhibited moderate desalination behavior with a TDS rejection of 62.45%, effectively improving permeate quality while avoiding excessive demineralization. Considering permeability, pollutant removal efficiency, and ion selectivity, the NF-3 membrane delivered the best overall purification performance in this study and shows strong potential for practical engineering applications.
  • WANG Ruilin, DI Jianying, LI Qichen, ZHANG Hongliang, LI Kai, QI Yaling
    Technology of Water Treatment. 2026, 52(9): 161-166.
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    To meet the requirements for further upgrading of effluent quality related to organic pollutants, nitrogen, phosphorus, and other parameters in the tailwater from a 5 000 m3/d wastewater treatment plant (WWTP) in a petrochemical industrial park, a combined constructed wetland system integrating a denitrification filter, two‑stage vertical subsurface flow wetland, and surface flow wetland was employed for advanced purification. One‑year operational monitoring demonstrated that the integrated wetland system achieved stable and efficient purification performance: the average effluent concentrations of COD, TN, NH3‑N, and TP were 22.8 mg/L, 7.3 mg/L, 0.4 mg/L, and 0.1 mg/L, respectively, corresponding to average removal efficiencies of 36.8%, 42.9%, 88.2%, and 51.3%. The effluent BOD₅ concentration remained below the detection limit. The final effluent quality met and exceeded the discharge limits specified in the Discharge Standard of Water Pollutants for Minjiang River and Tuojiang River in Sichuan Province (DB 51/2311–2016). This project is characterized by relatively low capital investment and operational costs, along with remarkable ecological and social benefits. It plays a vital role in ecological protection within the Minjiang River Basin and adjacent regions, and thus can provide a valuable reference for the construction and application of large‑scale tailwater purification wetlands.
  • LIAO Kan, CHEN Kunxiong, WANG Jingyu, FENG Danfeng, CHEN Zhenguo, WANG Xiaojun
    Technology of Water Treatment. 2026, 52(9): 167-172.
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    To address the challenges associated with industrial-domestic mixed wastewater treatment, including significant fluctuations in influent quality and stringent requirements for nitrogen and phosphorus removal, a municipal wastewater treatment plant with a design capacity of 3×104 m3/d was investigated. The performance of a combined process combining "pretreatment + CASS + high-efficiency sedimentation + denitrification deep bed filter" was analyzed. By optimizing the operational phase configuration of the CASS process and carbon source dosing strategy, a synergistic control mechanism of "temporal sequencing-carbon source matching" was established, which enhanced nitrogen removal stability under low C/N conditions from a mechanistic perspective. Meanwhile, a water reuse strategy was incorporated to promote the transition from pollutant removal to water resource recycling. Based on the evaluation of 20 months' continuous operation data, the system showed good removal effect on CODCr, NH3-N, TN and TP under the condition of average treatment water volume of 2.2×104 m3/d, and the long-term stability of effluent quality was better than the Grade A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918–2002). The treatment cost was approximately 1.15 yuan/m3. The results demonstrate that the proposed process exhibits strong adaptability and operational stability for complex mixed wastewater, and its control strategy and resource-oriented design provide valuable references for similar applications.