Arsenic removal using oxidative media and nanofiltration.

This article discusses a study that demonstrated the introduction of a membrane-compatible arsenic oxidation step that enables nanofiltration (NF) or reverse osmosis (RO) systems to treat waters contaminated with arsenite. Two NF membranes and one RO membrane were used for evaluation. A programmable logic controller (PLC) controls the membrane filtration system. Characteristics of the groundwater in Virden, Manitoba include high total organic carbon (TOC), alkalinity, total dissolved solids, ammonia and turbidity, and low in hardness. Results showed that arsenic rejection was low for membranes 1 and 2, while membrane 3 achieved a 51% arsenic rejection. The rejection of arsenic was influenced by certain membrane conditions.