Removal of pharmaceutical compounds from sewage effluent by the nanofiltration membrane

Abstract

Membrane is a promising technology for water treatment, and its commercial production has emerged globally. However, commercial membranes' effectiveness is still uncertain due to the new types of contaminants, such as pharmaceutical compounds (PC). Thus, in the current work, the performance of two commercial membranes (NFX and GC) has been evaluated using feed water from the effluent of sewage treatment plants (STP) and hospital wastewater (HWW). The spiked feed water contains PC classes of analgesics/anti-inflammatory, anti-hypertensives, beta-blockers, and psychiatric/antidepressants. The percentage difference between feed and permeate was measured. While the fouling properties of the membranes are also evaluated using STP and HWW as feed, along with the pure water flux in a variable-pressure setting, the results showed that NFX exhibits excellent, consistent rejection for the targeted PCs (>80 %). GC showed a broader range of rejection (10 % to 90 %) and presented a better flux flow than NFX. The main rejection factor is due to the membrane's pore size variation and the layer construction, which refer to the absorption, size exclusion, and diffusion of the PCs instead of the type of feed water and the flux. Current work provides scientific data on the diverse fabrication and market-available types of membranes, which would pose various efficiencies towards the type of targeted pollution.