Integrated Approach for Developing Sustainable Methodology for Sewage Recycling A Case Study of Surat

Abstract

Water resources across the globe are depleting at an alarming rate due to the drastic population growth, urbanization, industrialization and the consequent demand for the freshwater resources. The increase in demand for the water resources cannot be controlled, however their excessive use can be kept in check if a better alternative for freshwater is found for non-potable purposes. At this juncture, tertiary treated sewage can be considered a viable option. Proper treatment of sewage can ensure a sufficient supply of treated water for industrial use. In India, several Sewage Treatment Plants have been set up by the Central and State Government Bodies for Cities and Towns and the biologically treated sewage can be further processed for tertiary treatment and non-potable purpose. newlineMany industries are located within the perimeter of 25 km of Surat, which require about 500-600 MLD of process water for use in industries. There are many Textile Processing and Chemical units located within Udhna, Pandesara, Sachin and Palsana Industrial Estates around Surat. Surat Municipal Corporation (SMC), on request of surrounding industries particularly from Pandesara and Sachin Industrial Estates, installed Tertiary Sewage Treatment Plant to supply them Product Water for their industrial processes. SMC has 100 MLD Sewage Treatment Plant (STP) at Bamroli with UASB + EA System and 40 MLD (Net Output) Tertiary Treatment Plant (TTP) installed during the year of 2014 to use biologically treated sewage from this Plant. During initial study of operation of TTP, ingress of industrial waste in the raw newlinesewage was observed and due to this two major problems were faced namely (1) Higher TSS level thereby disturbing high rate gravity filter and not achieving TSS limit of 5 mg/L as UF feed as required by UF membrane manufacturer (2) The second problem observed was irreversible fouling of UF Membranes thereby reducing the flux level by 20% affecting the requirement of product water to be supplied to Industries.