Processing of residual water by reverse osmosis

Abstract

Considering the problems related to issue of water resources, this study aims to analyze the wastewater recovery stage of the waste, from the reverse osmosis application, to replenish water in cooling towers. The present study was based on data obtained from industrial process of residual water recovery by reverse osmosis for replacement in cooling tower connected series to a heat exchanger system. Before the system, a daily continuous discharge (purge) of 7.81m³/h was installed, which was required to maintain the silica concentrations inside the specified parameter. After the implementation of the new unit of reverse osmose, it was not necessary to perform a purge, due to the low concentration of solids dissolved in the water used for the replacement of water in the cooling tower. The reverse osmosis treatment of the tailings, in the initial stages, allowed supplying the water demand from the plant from the new system. The osmotic pressures of the processed water ranged from 0.53 to 1.61kPa. These values were considered small due to the low silica concentrations. On average, the mass transfer coefficient was 0.26kg.m-2 h-1 kPa.