Visual determination of nitrite and nitrate in waters by color band formation method.
A spot test for aqueous nitrate and nitrite for controlling nitrogen removal performance in small-scale wastewater treatment facilities is proposed. In this method, NO(2)(-) ion in water samples was allowed to react with sulfanilic acid and 1-naphthol to form an anionic azo dye. The resulting colored solution was introduced onto a mini column (similar to a gas detecting tube) packed with PVC particles coated with benzyl cetyl dimethyl ammonium chloride (BCDMA) and biphenyl. The NO(2)(-)-N concentration was determined visually by measuring the color band length (CBL) in the column. The CBL correlates linearly with nitrite concentration in the 4-20 mg-N l(-1) range. The concentration of nitrite+nitrate was determined after reduction to nitrite with zinc. The concentration of NO(3)(-)-N species was calculated by difference. This method was used to visually determine the concentrations of NO(2)(-)-N and (NO(2)(-)+NO(3)(-))-N in domestic wastewater samples with maximum suspended solid (SS) and chemical oxygen demand (COD) concentrations of 114 mg l(-1) and 73.9 mg l(-1), respectively.
Department of Ecological Engineering, Toyohashi University of Technology Tempaku-cho, Toyohashi 441-8580, Japan.
Yoshiaki
Y
Kiso
Yong-Jun
YJ
Jung
Kazumichi
K
Kuzawa
Yasunori
Y
Seko
Yoshihiro
Y
Saito
Toshiro
T
Yamada
Masahiro
M
Nagai
D000327:Adsorption; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid / Q000379:methods; D003116:Color; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D014867:Water / Q000032:analysis*
D009566:Nitrates; D009573:Nitrites; D014867:Water