Polishing effluent from a perchlorate‐reducing anaerobic biological contactor

The US Environmental Protection Agency undertook a three‐and‐a‐half‐year pilot‐scale anaerobic biological perchlorate treatment study that included two examinations (of 311 and 340 days each) of anaerobic effluent‐polishing temperatures ranging from 1.5 to 30°C (from 35 to 86°F). The aim of the study was to raise the anaerobic contactor effluent water quality to drinking water standards. Polishing restored dissolved oxygen to saturation levels and lowered carryover acetate electron donor to below the detection limit in warm weather, sulfide to below the detection limit in all temperatures, ammonia during warm weather, effluent turbidity in all temperatures, and disinfection by‐product formation potentials in all temperatures.