Meeting California's Hexavalent Chromium MCL Using Strong Base Anion Exchange Resin. Issue 9 (1st September 2016) - Li, Xue
Abstract : The use of five strong base anion exchange resins to treat three potable groundwater sources to meet the new California maximum contaminant level (MCL) for hexavalent chromium (10 μg/L) was investigated. Depending on the resin used, bed volumes treated before breakthrough of total chromium (to 8 μg/L) ranged from approximately 13, 800 to 26, 400. At the point of resin exhaustion, uptake of total chromium (meq/L) accounted for less than 1% of the exchange capacity reported by resin vendors, whereas the uptake of sulfate accounted for 54–76%. Reusing the brine nine times produced a tenfold reduction in the volume of spent brine requiring ultimate disposal without significantly impairing resin performance. Chromium breakthrough profiles were relatively insensitive to a change in empty bed contact time (0.75 and 2.25 min) and hydraulic loading rates (8–55 mL/min‐cm 2, 1.96–13.5 gpm/sf).