Relating organic fouling of reverse osmosis membranes to adsorption during the reclamation of secondary effluents containing methylene blue and rhodamine B.

Dyes fouling of reverse osmosis (RO) membranes and its relation to adsorption had been investigated by using a crossflow RO filtration setup. Methylene blue (MB) and rhodamine B (RB) were used as model organic foulants. The calculated amount of the irreversible sorption was related to the irreversible flux decline. The characteristic fouling kinetics was accounted by Langmuir-Hinshelwood (L-H) kinetics model for initial fouling, with the fouling rate constant k=0.0556μm s(-1)min(-1) and k=0.0181μm s(-1)min(-1) for MB and RB fouling RO membrane CPA2, respectively. And the subsequent fouling was attributed to the growth of a dye cake. A remarkable correlation was obtained between the quantified irreversible sorption and irreversible flux decline under the solution chemistries investigated. In the presence of divalent cation, the extent of flux decline was related to the competition model.