Efficient removal of nitrate and arsenic using a t <scp>wo‐stage</scp> b <scp>iotic‐abiotic</scp> treatment system

Nitrate and arsenic often co-exist in groundwater sources. Reverse osmosis, electrodialysis, ion exchange are the commonly implemented technologies for nitrate removal. Compared to these that generate high-strength waste streams, biological treatment converts innocuous nitrogen gas without producing a concentrated waste. When water source, combining biotic process removal with an abiotic (i.e., chemical–physical such as coagulation/flocculation) may provide effective approach simultaneous of contaminants. A 12-month pilot study was conducted two-stage, fixed-bed biotreatment system, originally developed removal, arsenic. With empty bed contact time low 10 min bioreactor, consistently lowered from ~35 mg/L N <0.1 (treatment target <1 N), whereas effectively ~14 μg/L <5 μg/L. Overall, results demonstrated efficient resilient using two-stage biotic-abiotic system.