SUSTAINABLE DRINKING WATER PRODUCTION FROM BRACKISH SOURCES USING PHOTOVOLTAICS

摘要

An estimated 1 billion people are living both without access to clean drinking water or electricity. In this paper we describe a small photovoltaic-powered hybrid membrane system that is designed to address the majority of the water quality problems. An ultrafiltration (UF) membrane is used to remove bacteria and most pathogens, while a reverse osmosis (RO) or nanofiltration (NF) membrane desalinates the brackish feedwater. Several parameters were examined in order to optimise the system performance, including I) feed water salt concentration, ii) operating pressure, iii) system recovery, iv) specific energy consumption (SEC, kWh/m3), and v) salt retention. In addition, experiments were performed over a whole day to determine system performance under varying levels of solar radiation. The minimum SEC varies from 5.5 kWh/m3 at a feed concentration of 1 g/L salt to 26 kWh/m3 at a feed concentration of 7.5 g/L salt. The relatively high SEC can be attributed to the single-pass operation mode of the membranes and will be significantly reduced in the future using a recycle stream.