Performance of chemically resistant polyurea reverse osmosis membrane in the treatment of highly alkaline industrial wastewater containing sodium aluminate

The goal of the present study is to treat industrial wastewater containing sodium aluminate using a chemically inert polyurea (PU) based thin film composite (TFC) reverse osmosis (RO) membrane to promote water reclamation and zero liquid discharge (ZLD). Pretreatment was carried out to reduce the pH of the effluent from 12.5 to 7.1. The TFC RO membrane was fabricated by coating PU on Polyethersulfone (PES) substrate by interfacial polymerization (IP). The surface and cross-sectional morphologies of the membrane were characterized using scanning electron microscopy (SEM). The indigenously synthesized membrane was effective in the removal of total dissolved solids (TDS), chemical oxygen demand (COD), colour and electrical conductivity. The experiments were conducted by varying the feed composition of the wastewater. The maximum water recovery and flux were found to be 74% and 73.9 L/m2.h. RO process using PU membrane exhibited significant potential for cost effective, safe and pollution-free treatment of sodium aluminate industrial effluent.