Arsenic removal from tap water by electrocoagulation: investigation of process parameters, kinetic analysis, and operating cost.

Presence of arsenic ion [As(V)] in ground water at different locations of India is a big health concern in present days. In this work, effort was made to remove As(V) ions from tap water by electrocoagulation (EC) using iron (Fe) electrodes having an effective surface area of 38.67 m²/m³. Investigation was focused on studying the effects of various process parameters of EC like solution pH, current density (CD), inter-electrode distance (IED) initial arsenic concentration (C_o), electrical conductivity of water on removal of As(V) in efficient ways. Experimental results reveal that initial pH of 7, CD of 0.431 mA/cm², IED of 0.5 cm, agitation speed of 200 rpm and NaCl dose of 0.33 g/L are optimal conditions to reduce As(V) ion concentration from 100 µg/L to below 10 µg/L. Overall, 99.4% As(V) removal was achieved at 30 minutes of EC treatment. Different quality parameters for drinking water such as TDS, turbidity, salinity, electrical conductivity were also assessed during the EC, to verify drinking water quality in several aspects. Kinetic analysis infers that As(V) removal by EC follow the first order reaction model. Present study affirms that, EC is an effective technique for efficient As(V) removal from drinking water with an estimated energy consumption of 8.33 × 10⁻³ Kwh/m³, electrode utilization of 0.0486 kg/m³, and operational cost of 0.0488 US$/m³. [ABSTRACT FROM AUTHOR]