PERTH, Australia – A benchmarking study has been carried out on the bacterial build up on reverse osmosis membranes at a full-scale desalination plant which could help prevent biofouling in future operations.

Murdoch University PhD student Veena Nagaraj examined the bacteria living on the membranes on 14 reverse osmosis units in the Perth seawater desalination plant in Rockingham after seven years of operation.

She then compared them to the unused units waiting in the plant for installation.

Before reaching the reverse osmosis membranes, the water has already gone through sand filtration, micro-filtration and chemical treatment to try to remove the bacteria/

Nagaraj said: “My study showed that although this pre-treatment wiped out lots of the contaminating bacteria, this just cleared away the competition for a few species to thrive in this environment.”

The study found that there were a few groups of Proteobacteria, which had the characteristics to help them to start the biofouling community on the membrane.