Integrating biological As(III) oxidation with Fe(0) electrocoagulation for arsenic removal from groundwater

• We integrated As(III) oxidizing bacteria with Fe electrocoagulation (bio-FeEC). Effective removal of to WHO guideline in bio-FeEC than conventional FeEC. Bio-FeEC created less sludge and used power is a promising alternative arsenic treatment technologies. Arsenic (As) toxic element present many (ground)water sources the world. Most As techniques require pre-oxidation neutral arsenite (As(III)) species negatively charged arsenate (As(V)) oxyanion optimize minimize chemical use. In this work, novel, continuous-flow system was developed that combines biological oxidation by (EC), an Fe(0)-based electrochemical technology generates reactive Fe(III) precipitates bind As. The bio-integrated FeEC (bio-FeEC) showed effective 150 µg/L As(III), without need chemicals. To remove below 10 µg/L, times lower charge dosage required for compared This requirement reduced production energy consumption. biomass found consist belonging Comamonadaceae, Rhodobacteraceae Acidovorax , which are capable common drinking water biofilms. Characterization As-laden solids X-ray absorption spectroscopy indicated both produced consistent mixture lepidocrocite 2-line ferrihydrite. bound dominantly As(V), but slightly higher fraction As(V) detected