Potential of ceramic microfiltration and ultrafiltration membranes for the treatment of gray water for an effective reuse

Abstract

Gray water may serve as a water resource for agricultural uses due to their high nutrient content. In this study performance evaluation of indigenously developed low-cost ceramic membrane was investigated for treatment and reuse of high organic loaded gray water. The efficiency of microfiltration (MF) and ultrafiltration (UF) process was studied individually and as a two-stage treatment involving MF followed by UF. Effect of time was observed on reduction of chemical oxygen demand (COD) in the permeate stream and permeate flux in different processes. Depending on the variation in feed loading, about 73–90% COD reduction was achieved in the single-stage UF at 30 min of filtration with operating pressure of 2 bar, which was about 84–94% for two-stage treatment. Permeate quality in terms of organic loading, oil and grease and coliform concentration were found suitable according to the discharge norms for agricultural reuse of water. The effect of untreated, MF- and-UF treated wastewater was observed on a popular palm species, Chrysalidocarpus lutescens H. Wendl. The study showed significant potential for use of the MF- and-UF treated water which facilitated an enhanced uptake of most of the essential nutrients in plants compared with that of fresh water.