Performance of a small solar-powered hybrid membrane system for remote communities under varying feedwater salinities
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Date
2004Author
Schäfer, Andrea
Remy, C.
Richards, B.S.
Metadata
Abstract
An estimated 1 billion people are living both without access to clean drinking water or electricity. The small
photovoltaic (PV)-powered hybrid membrane system described here is designed to address the plight of some of
these people. PV and membrane technologies are chosen due to suitability for operation in remote and often harsh
conditions. An ultrafiltration (UF) pre-treatment is included 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 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 (relatively high due to the current single-pass mode of operation) 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, which is the
upper limit of the system in terms of salt concentration.