Treatment of nitrate contaminated water using an electrochemical method.
Treatment of nitrate contaminated water which is unsuitable for biological removal using an electrochemical method with Fe as a cathode and Ti/IrO(2)-Pt as an anode in an undivided cell was studied. In the absence and presence of 0.50 g/L NaCl, the nitrate-N decreased from 100.0 to 7.2 and 12.9 mg/L in 180 min, respectively, and no ammonia and nitrite by-products were detected in the presence of NaCl. The nitrate reduction rate increased with increasing current density, with the nitrate reduction rate constant k(1) increasing from 0.008 min(-1) (10 mA/cm(2)) to 0.016 min(-1) (60 mA/cm(2)) but decreasing slightly with increasing NaCl concentration. High temperature favoured nitrate reduction and the reaction followed first order kinetics. The combination of the Fe cathode and Ti/IrO(2)-Pt anode was suitable for nitrate reduction between initial pH values 3.0 and 11.0. e.g. k(1)=0.010 min(-1) (initial pH 3.0) and k(1)=0.013 min(-1) (initial pH 11.0). Moreover, the surface of all used cathodes appeared rougher than unused electrodes, which may have increased the nitrate reduction rate (4-6%).
Li
Miao
M
School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, China.
Feng
Chuanping
C
Zhang
Zhenya
Z
Yang
Shengjiong
S
Sugiura
Norio
N
D004563:Electrochemistry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D009566:Nitrates; D014874:Water Pollutants, Chemical