Arsenic Removal from Drinking Water by Self-Made PMIA Nanofiltration Membrane

Abstract

A self-made PMIA asymmetric nanofiltration membrane was used for arsenic removal from drinking water by NF process. Effects of feed concentration, operating pressure, pH and existing ions on As(V) removal were investigated. Experimental results showed that As(V) rejection was higher than 90% in the range of investigated As feed concentrations. The As(V) rejection increased slightly with pressure increase, As(V) rejection was higher than 90% in the pressure range of 0.4 MPa to 0.8 MPa. As(V) rejection increased significantly from 83% at pH 3 to 99% at pH 9. The presence of NaCl enhanced As(V) rejection in the range of feed concentration, and As(V) rejection can reach up to 99% at a feed As concentration of 100 μg/L, whereas there was a rejection decrease of 8% in the presence of Na2SO4 at every feed concentration. The results showed the As(V) detected in the permeate was lower than the EPA recommended MCL up to a feed As concentration of approximately 10 μg/L in the experimental research range.