Enhancing Contaminant Removal in Sewage Treatment Plant Effluent with PES/Ag Membrane

Abstract

In this study, a silver-infused membrane was fabricated using an ex-situ method that involved blending silver nanoparticles (AgNPs) with Polyethersulfone (PES) as the base polymer in treating sewage treatment plant (STP) effluent. Three distinct membranes denoted as S1(Ag0), S2(Ag0.5) and S3(Ag2.0) were manufactured with varying weight percentages of polymer and silver (Ag) contents. The objective was to investigate the effect of the dosage of AgNPs on membrane characterization and performance, encompassing pure water flux filtration tests, organic rejection tests, and antibacterial properties. The results showed that all PES/Ag membranes demonstrated robust performance in removing total suspended solids (TSS), chemical oxygen demand (COD), apparent colour (Hazen unit), total dissolved solids (TDS), turbidity, conductivity, total Kjeldahl nitrogen (TKN), and Escherichia coli (E. coli), complying to Class IIB (Recreational use with body contact) of the Interim National River Water Quality Standards (INWQS) for Malaysia ruled by the Department of Environment Malaysia (DOE). The results also highlighted that upon the addition of AgNPs, the E. coli removal of the membrane S3(Ag2.0) was further improved to 99.87%. The results have evidenced that the PES/Ag membranes could reject E. coli effectively, proving their value in treating bacteria-contaminated surface water. In conclusion, this study highlights the effectiveness of PES/Ag membranes as a viable solution for domestic sewage treatment, aligning with stringent water quality requirements.