Testing of a hybrid membrane system for groundwater desalination in an Australian national park

The results of a field trial desalinating brackish bore water in an Australian remote national park site are reported in this paper. Two membranes, operated with varying operation pressures, were tested with regards to flux, recovery, retention, power and specific energy consumption. The aim of such a performance evaluation is the determination of a safe operating window when the system is driven with solar energy and hence a variable power source. Submerged ultrafiltration was effective in reducing high feedwater turbidity of up to 370 NTU. For the system, designed for a production of about 1000 L/d for remote communities, the specific energy consumption (SEC) was below 5 W.h/L when operated at a pressure above 7 bar. Retention of multivalent ions was stable at >98% while the retention of monovalent ions varied between 88 and 95% depending on system pressure with a maximum between 7 and 10 bar.