Evaluating the efficiency of reverse osmosis desalination after its mitigation at subacid cation resin

Abstract

The evaluation of the efficiency of the low-mineralized water desalination at reverse osmosis membranes Filmtec TW 30-1812-50 depending on the water characteristics was performed. The influence of stabilizing treatment on the weak acid cation exchange resin in the acid form was determined on the basis of membrane characteristics. It is shown that acidification of water during the processing on the weak acid cation exchange resin reduces the membrane selectivity for chlorides while the selectivity for sulfate and water hardness ions remains high. During weak acid solutions treatment on the membrane the pH level in concentrate and permeate is approximately equal, while filtering the original model solution rises pH level in the concentrate to 9, and in permeate reduces to 7, due to the lower membrane selectivity for hydrocarbonate, compared with the water hardness ions.