AWWA MTC69659

Nitrate and perchlorate in drinking water sources are of major health concerns because they can cause adverse health effects on human and ecosystems. While it is technically possible to treat nitrate and perchlorate in water supplies, it can be difficult, expensive and not totally effective. This work evaluates the feasibility of new membrane hybrid systems for the removal of nitrate and perchlorate from drinking water. This hybrid system combines low pressure reverse osmosis (LPRO) and ion exchange membranes (IEM) to achieve high recovery of permeate flow and low energy consumption. Different configurations of hybrid systems were compared to find out the optimum process configuration. The study carried out experiments using a laboratory-scale IEM device and pilot-scale RO equipment. Four kinds of ion exchange membranes were compared based on membrane transport analysis. A spiral wound LPRO membrane was used for RO filtration test. Membrane transport studies showed that IEM is suitable for obtaining water with concentrations of nitrate below the recommended levels. LPRO could reject 80%-95% of nitrate even at transmembrane pressure below 800 kPa. The optimum combination of IEM and LPRO is likely to be effective for high removal efficiency of nitrate with low energy consumption. Includes 8 references, tables, figures.