Abstract: “The main focus of this research is to investigate the mechanisms of flux decline during the organic and colloidal fouling of a thin-film composite (TFC) polyamide membrane operated in osmotically driven membrane process (forward osmosis). It has been found that flux decline by humic acid was minimal while the attachment of colloidal particles resulted the gradual decline in forward osmosis. The main mechanism of the flux decline in forward osmosis is due to the colloid-enhanced osmotic pressure (CEOP) due to the salt build-up near the membrane surface and was reversible by the removal of attached particles. Combined organic and colloidal fouling did not cause any flux decline which showed similar results with humic acid fouling alone due to the increase of negative charge on the membrane surface by adsorbed humic acids.”

Keywords: Forward osmosis; membrane; humic acid; colloidal fouling; organic fouling