Research on Reverse Osmosis biofouling formation

In this paper the inorganic effect on RO membrane biofouling formation, especially the initial stages, was researched. Three same experimental setups were run to dispose of different raw water. The result show the precipitated salts contribute more than microorganism to initial biofilms formation, but bacterial counts more favor biofilms maturation on the membranes surface. At the end of running experiment, the severer polluted RO element was anatomized. The microcosmic of membranes surface was scanned by SEM, and the elements were studied by EDX and organic matter were analyzed by GC/MS and FTIR. The result shows that the aromatic ring, fatty acid and little polysaccharides are foulant primary ingredients besides little inorganics such as Si, Ca, Mg, and Al. The biofilms growth is synergistic of inorganic salts with microorganisms and organic macromolecules on the membranes surface. It could be safely deduced that there is an inorganics coarseness formation stage before the biofilms formation, and verified by subsequently cleaning experiment. Therefore, the formation mechanism of biofouling can be divided into five stages, but isn't the four stages brought forward by Flemming in 1998.