Polyelectrolyte Functional Bilayers for the Removal of Model Emerging Contaminants

A sustainable approach for the removal of pharmaceutical contaminants from effluent using polyamide thin-film composite membranes integrated with Zn-based metal organic frameworks

This study addresses the significant concern of pharmaceutical contaminants, including antipyretic and antibiotic drugs, in municipal and industrial wastewater, impacting both the environment and human health. We investigate incorporating zinc-based metal-organic framework (Zn-MOF) nanofillers into polyamide layers, developing thin-film composite (PA-TFC) nanofiltration membranes via interfacial polymerization to remove paracetamol, ibuprofen, and amoxicillin from simulated wastewater. Characterization confirms Zn-MOF's presence in the PA-TFC membrane, affecting structural topology, pore size, contact angles, and zeta potential. Zn-MOF nanofillers strongly adhere to the polyamide layer, influencing membrane surface chemistry and morphology. The newly developed MOF/PA-TFC nanofiltration membranes demonstrate a remarkable water flux of up to 35 LMH, showcasing superior removal efficiency for the three pharmaceutical contaminants when compared to PA-TFC membranes. Specifically, the rejection rates for paracetamol, ibuprofen, and amoxicillin are notably high at 93%, 98%, and 99%, respectively. Consequently, this study establishes MOF/PA-TFC nanofiltration membranes as a highly efficient solution for removing emerging pharmaceutical contaminants from environmental water, promoting sustainability and safeguarding water resources.

Direct conversion of wet sewage sludge to carbon catalyst for sulfamethoxazole degradation through peroxymonosulfate activation

The high moisture content of wet sewage sludge generated from wastewater treatment process not only brings high cost of sewage disposal, but also limits its utilization as resource. In this study, an efficient strategy of directly utilizing wet sludge to develop advanced carbocatalyst via a hydrothermal coupled pyrolysis process was proposed. The possible application of as-synthesized carbocatalyst was evaluated by activating peroxymonosulfate (PMS) to degrade a model pollutant of sulfamethoxazole (SMX). Experimental results showed that about 100% of SMX and 59% of total organic carbon (TOC) could be removed within 15 min. Moisture content in wet sludge also affected the performances of as-obtained carbocatalysts. Further studies verified that singlet oxygen (¹O₂) dominated SMX degradation, which was generated in the process of PMS activation by CO groups on the surface of carbocatalyst. In the preliminary ecological test, a lower ecotoxicity of SMX degradation solution compared with the original solution was observed. This study demonstrated the feasibility of directly utilizing wet sludge for advanced carbocatalyst fabrication, which provided another solution for wet sludge treatment and utilization.