MEMBRANE-INTEGRATED HYBRID TREATMENT SYSTEM FOR ARSENIC REMOVAL

摘要

Experimental investigations were carried out to separate arsenic from contaminated groundwater by using three different types of nanofiltration membranes in a flat sheet cross flow membrane module with a pre-oxidation step for conversion of trivalent arsenic to pentavalent form. Effects of pressure, iron concentration in groundwater, pH, and pre- oxidation on the performance of the membranes in terms of flux as well as percentage rejection of arsenic were studied. Overall arsenic removal increased from 50-63 percentages to 97-100 percentages on pre-oxidation of trivalent arsenic. Polyamide composite nanofiltration membrane fitted in a cross flow membrane module can successfully remove arsenic from contaminated groundwater with a pre-oxidation step.