AWWA JAW62338

With the new arsenic maximum contaminant level (10 µg/L) set to take effect this month, water suppliers will be interested in this novel, new technology for arsenic removal. A polyelectrolyte-enhanced ultrafiltration (PEUF) process was used to treat water with low concentrations of arsenic. The researchers' objectives were: to verify that the performance seen in batch studies was representative of pilot-scale spiral-wound membrane results; and, to evaluate the general economic viability of the PEUF system. Arsenic-tainted waters often have elevated pH values. With the PEUF technology, arsenic-polymer binding actually improved at higher pH values, giving this technology an advantage over competing technologies that perform better at lower pH values. Although the arsenic-polymer binding decreased with increasing sulfate concentration, this could be mitigated by increasing the ratio of cationic polyelectrolyte to arsenic. Other membrane processes for arsenic removal require higher operating pressures than PEUF, and thus they generate higher capital and operations and maintenance costs. PEUF uses the novel polymer-arsenic complexation to reduce the pressure requirement. This new alternative treatment also shows how utilities can make existing technologies more cost-effective. Using design parameters and water quality conditions as described in this article, the PEUF process was shown to be technically and economically viable for the removal of arsenic from drinking water. Includes 40 references, tables, figures.