SEPARATION OF HUMIC SUBSTANCES BY POROUS ION-EXCHANGE MEMBRANES FROM SULFONATED POLYSULFONE

Ultrafiltration involving sulfonated polysulfone membranes provides high efficiency for humic matter removal from water. The increase in ion-exchange capacity of the polymer matrix from 0.24 to 0.96 mmol SO3H groups per 1 g of dry membrane increases the membrane pore diameter and its hydrophilicity, and thus the permeate flux from 0.05 to 3.69 m3/m2.d. In order to decrease the manufacturing cost, membranes from polysulfone and sulfonated polysulfone blends were investigated. It was shown that a one-to-one blend resulted in a membrane having similar antifouling properties to pure sulfonated polysulfone. Both membranes reject humic matter in the 91-98% range and show a flux decline of 5-30% as a result of surface fouling.