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In this study, a novel CoFe 2 O 4 nanocatalyst impregnated Al 2 O 3 ceramic membrane was prepared via a urea-assisted one-step combustion method. The catalytic membrane was characterized by field emission scanning electron microscopy (FESEM) with energy dispersive X-Ray analysis (EDX) and applied for the catalytic degradation of sulfamethoxazole (SMX) via peroxymonosulfate (PMS) activation under a dead-end membrane filtration mode for the first time. Results indicate that CoFe 2 O 4 could be impregnated into the macropores throughout the whole Al 2 O 3 ceramic membrane via this method and the CoFe 2 O 4 loading amount could be controlled by the multiple impregnation cycles. The membrane filtration operation mode significantly enhances the accessibility of the catalytic active sites to PMS and SMX in microreactor environment and thus the CoFe 2 O 4 impregnated membrane displays excellent catalytic activity for the SMX degradation. The pure water permeability flux can maintain at ∼3000 L m −2  h −1  bar −1 (LMHB) with the catalyst loading amount of 0.015 g/g Al 2 O 3 . In the membrane filtration system, the removal rate of SMX with the initial concentration of 10 mg L −1 can achieve to ∼98%, 70% and 40% with the residence time of 90, 36 and 18 s. The catalytic membrane shows a great tolerance at wide pH range (3–11), the existence of humic acid and anions. Meanwhile, the membrane shows self-cleaning property by retaining >90% of initial flux after 3 treatment cycles. Electron paramagnetic resonance (EPR) and radical quenching experiments indicate that both sulfate radical and hydroxyl radical are generated and sulfate radical is the dominant active species in the process. [ABSTRACT FROM AUTHOR]

[Display omitted] • The nature and classification of silver-containing wastewater is summarized and analyzed; • Various treatment methods for silver-containing wastewater are comprehensively described and compared; • The future direction of silver containing wastewater treatment technology is proposed. Due to its exceptional physicochemical characteristics of silver, silver is widely used in various industrial applications such as photography, minting, electroplating, and metal alloys. As a result, a significant amount of wastewater containing silver is generated. It would cause serious harm to both humans and the natural environment if left untreated, leading to the wastage of precious silver resources in the process. Therefore, this study provides a detailed introduction to the types, characteristics, and hazards of silver-containing wastewater. Furthermore, this study offers a comprehensive overview of the research advancements in treating silver-containing wastewater through various methods including chemical precipitation, electrochemical method, adsorption, ion exchange, membrane filtration, photocatalytic method, and integrated techniques. Based on this foundation, the removal effects and mechanisms of various treatment methods are thoroughly discussed in conjunction with experimental studies and characterization tests. Furthermore, this study conducts a comparison of the advantages, disadvantages and scope of application of various treatment methods. Additionally, it anticipates the future development of silver-containing wastewater treatment technologies. [ABSTRACT FROM AUTHOR]

• Functionalized PAN-Co-C membranes were developed via one-step PAN carbonization. • Co works as a dual-functional catalyst in tuning carbon formation and PMS activation. • All functionalized membranes could activate PMS to generate sulfate radicals. • High permeability was attributed to the formation of graphite carbon and cobalt. • The membrane showed excellent antifouling property with high HA removal. A novel polyacrylonitrile (PAN)-induced carbon membrane with in-situ encapsulated cobalt crystal was developed via a one-step carbonization method and applied for peroxymonosulfate (PMS) activation. The dual-function of cobalt in tuning carbon formation and activating PMS was explored. The growth mechanism of the functionalized membrane was investigated via TGA-DSC, FTIR, XRD, Raman and XPS. Results indicated that the addition of cobalt could tune the formation of C and N containing functional groups in the carbon membrane. The membrane morphologies and surface properties were further characterized by FESEM and AFM. Batch studies revealed that more than 90% of sulfamethoxazole (SMX) could be degraded after 60 min of membranes exposure in the presence of PMS. Electron paramagnetic resonance (EPR) results verified the generation of sulfate radical in this process. The removal of humic acid (HA) in a dead-end membrane filtration mode could be maintained at ∼100% with an inconspicuous sacrifice of permeate flux over 450 min. The permeate flux achieved with PMS was higher as compared to the case without PMS addition, which could be ascribed to the catalytic oxidation of organic molecules accumulated on the membrane surface. The catalytic property imports an intrinsic antifouling property of the carbon membrane in the hybrid catalytic membrane filtration process. [ABSTRACT FROM AUTHOR]

• An acid-stable polyamine NF hollow fiber module was prepared for phosphorus recovery via the IP method. • Tannic acid interlayer was first constructed onto the PES substrate to assist the spreading of the aqueous phase. • The resultant NF membrane shows only 9.6% rejection of phosphorus, alongside over 93.5% rejection of metal ions at pH 2. • Membrane water permeability can reach 20.3 LMH/bar. The hazardous heavy metals coexisting with phosphorus-containing sewage sludge seriously limit phosphorus recovery. Nanofiltration (NF) membrane, which can selectively separate heavy metals and phosphorus, has a promising potential for recovering high-quality phosphorus from sewage sludge. In this work, we utilized the undissociated form of H 3 PO 4 at pH <2 and customized an acid-stable polyamine NF membrane via interfacial polymerization (IP) for separating phosphorus and heavy metals under acidic conditions. An interlayer formed via co-deposition of tannic acid (TA) and diethylenetriamine (DETA) was firstly coated onto the polyethersulfone (PES) hollow fiber module to assist the spreading of aqueous phase on the substrate surface. Consequently, a tight and positively charged polyamine layer with a mean pore size of 0.77 nm was successfully constructed on the PES substrate, which is smaller than that of the membrane without interlayer (1.39 nm). This polyamine membrane maintained excellent stability during 15-day acid testing with 0.1 M HCl as feed solution. When it was used to recover phosphorus at acidic condition (pH 2), the phosphorus rejection of the NF membrane was only 9.8 %, much lower than that at neutral pH (46.7 %), which is due to the fact that most phosphorus existed in the undissociated form of H 3 PO 4 at pH 2. Meanwhile, given the fine-tuning pore size and Donnan exclusion effect of this membrane, it could effectively retain 96.9 % of Mg2+ and over 93.5 % of most heavy metal ions such as Pb2+, Cu2+, Fe3+, Zn2+, and Cr3+, alongside outstanding water permeability of 20.3 LMH/bar at 2-bar operation pressure. This result demonstrates the potential of our homemade polyamine membrane in phosphorus recovery. [ABSTRACT FROM AUTHOR]