摘要：Oxidation of the manganese by atmospheric oxygen is a widely used method for drinking waters. The purpose of this study was to determine the effects of some organic substances (glutamic acid, vanillin and citric acid) on converting/stabilizing Mn~(2+) to and Mn~(4+).This study has been carried out in two stages. All experiments were carried out in a condition of alkalinity: 1.2x10~(-2)eq/L, pH=9.5, T=25°C,pO_2=0.21 atm, [Mn~(2+)]_o=3 mg/L. In the first stage, catalytic effect of Mn~(4+) has been experimentally investigated when it's increased up to about 400 mg/L, keeping Mn~(2+) constant at 3 mg/L with pH:9.5. In the second stage it has been studied how oxidation of Mn~(2+) and the catalytic effect of MnO_2 are affected by some organic matters. The effect of MnO_2 on Mn~(2+) oxidation in media containing organic substances (glutamic acid, vanillin and citric acid), was simulated and investigated experimentally.In media without organic acids, MnO_2 increases the oxidation rate of Mn~(2+). When glutamic acid is added, the catalytic effect of MnO_2 clearly decreases and almost vanishes. This is considered to be a result of glutamic acid-forming complexes with MnO_2. In contrast, it is seen that vanillin does not affect the catalytic effect of MnO_2 and the oxidation rate of Mn~(2+). Citric acid slightly increases the catalytic effect of MnO_2.
关键词：Manganese;organic compounds;catalytic effect;drinking water
