Removal of Arsenic from Water Using Amphiphilic Molecules and Ultrafiltration Membranes

Arsenic (V) removal using cetylpyridinium chloride (CPC) micelles and 5 kilo-Dalton (kDa) polyethersulfone (PES) membrane was studied in the presence of multiple co-ions. The concentrations of arsenic ([As]F = 0 105 μg/L) and co-ions ([CO3] = 0 – 4 mg/L, [PO4] = 0 – 0.3 mg/L, [SiO3] = 0 – 71 mg/L, and [SO4] = 0 – 400 mg/L) in simulated feed water were varied. Without the addition of CPC micelles, the PES membrane was found to be ineffective for arsenic removal. In the presence of co-ions, the highest arsenic removal was 25%. However, the addition of CPC micelles significantly increases the arsenic removal efficiency. Regardless of the presence of co-ions, the arsenic concentrations in permeate water were consistently reduced well below the new maximum contaminant level (MCL) of 10 μg/L. The repeatable results obtained suggest that using ultrafiltration membranes with CPC micelles can be an alternative treatment technology for arsenic removal from contaminated water.