title: Factors influencing arsenic and nitrate removal from drinking water in a continuous flow electrocoagulation (EC) process.
abstract: An experimental study was conducted under continuous flow conditions to evaluate some of the factors influencing contaminant removal by electrocoagulation (EC). A bench-scale simulation of drinking water treatment was done by adding a filtration column after a rectangular EC reactor. Contaminant removal efficiency was determined for voltages ranging from 10 to 25 V and a comparative study was done with distilled water and tap water for two contaminants: nitrate and arsenic(V). Maximum removal efficiency was 84% for nitrate at 25 V and 75% for arsenic(V) at 20 V. No significant difference in contaminant removal was observed in tap water versus distilled water. Increase in initial As(V) concentration from 1 ppm to 2 ppm resulted in a 10% increase in removal efficiency. Turbidity in the EC reactor effluent was 52 NTU and had to be filtered to achieve acceptable levels of final turbidity (5 NTU) at steady-state. The flow regime in the continuous flow reactor was also evaluated in a tracer study to determine whether it is a plug flow reactor (PFR) or constantly stirred tank reactor (CSTR) and the results show that this reactor was close to an ideal CSTR, i.e., it was fairly well-mixed.
authors.affiliation: Civil Engineering Department, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: N Sanjeev
authors.initials: NS
authors.lastname: Kumar
authors.forename: Sudha
authors.initials: S
authors.lastname: Goel
mesh_terms: D001151:Arsenic / Q000302:isolation & purification*; D004553:Electric Conductivity; D004563:Electrochemistry; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D009391:Nephelometry and Turbidimetry; D009566:Nitrates / Q000302:isolation & purification*; D012722:Sewage / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*
chemical_list: D009566:Nitrates; D012722:Sewage; D001151:Arsenic