title: Simultaneous reduction of nitrate and oxidation of by-products using electrochemical method.
abstract: Electrochemical denitrification was studied with an objective to enhance the selectivity of nitrate to nitrogen gas and to remove the by-products in an undivided electrochemical cell, in which Cu-Zn cathode and Ti/IrO(2)-Pt anode were assembled. In the presence of 0.50 g/L NaCl as supporting electrolyte, the NO(3)(-)-N decreased from 100.0 to 9.7 mg/L after 300 min electrolysis; no ammonia and nitrite were detected in the treated solution. The surface of the cathode was appeared to be rougher than unused after electrolysis at initial pH 6.5 and 12.0. After electrolysis of 5h at the initial pH 3.0, passivation of the Cu-Zn cathode was observed. The reduction rate slightly increased with increasing current density in the range of 10-60 mA/cm(2) and temperatures had little effect on nitrate reduction. Nitrate could be completely removed by the simultaneous reduction and oxidation developed in this study, which is suitable for deep treatment of nitrate polluted water.
authors.affiliation: Doctoral Program in Life and Environmental Sciences, University of Tsukuba, Tsukuba 3058572, Japan.
authors.forename: Miao
authors.initials: M
authors.lastname: Li
authors.forename: Chuanping
authors.initials: C
authors.lastname: Feng
authors.forename: Zhenya
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Lei
authors.forename: Rongzhi
authors.initials: R
authors.lastname: Chen
authors.forename: Yinan
authors.initials: Y
authors.lastname: Yang
authors.forename: Norio
authors.initials: N
authors.lastname: Sugiura
mesh_terms: D000641:Ammonia / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004572:Electrolysis; D005609:Free Radicals / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods; D015032:Zinc / Q000737:chemistry
chemical_list: D005609:Free Radicals; D009566:Nitrates; D009573:Nitrites; D014874:Water Pollutants, Chemical; D014867:Water; D012965:Sodium Chloride; D000641:Ammonia; D003300:Copper; D015032:Zinc; D010100:Oxygen