[Kinetics on ethanethiol oxidation by potassium permanganate in drinking water].

Reaction kinetics of ethanethiol oxidation with potassium permanganate in water was studied, and the effect of ethanethiol oxidation in raw water under coagulation condition has been investigated. The results showed that the oxidation reaction of ethanethiol by potassium permanganate was very efficient, the removing effect could be more than 90%. The rate of ethanethiol decomposition by potassium permanganate in aqueous solution followed second-order kinetics. When potassium permanganate was excessive, pseudo-first-order rate and concentration of potassium permanganate followed the equation: k' = 0.025 [KMnO4] - 0.008. And then, the second-order reaction rate constant was k = 0.025 L/(min x mg). The removal of ethanethiol in raw water by potassium permanganate under coagulation condition was poorer than in pure water condition, So predicted concentration of potassium permanganate was lower than real concentration.

[Removal technology of typical odorant in drinking water].

To eliminate the odor in drinking water of one City in China, a study was performed on the typical odorant removal technology and removal processes. Its results showed that as typical odorants, ethanethiol was effectively removed by oxidation and geosmin and 2-MIB were removed by both oxidation and adsorption, but geosmin and 2-MIB's adsorption effect was better than oxidation. When thiol and thioether in raw water was less than 20 microg/L, furthermore, there was not any other odorant, potassium permanganate oxidation should be equipped with enhanced coagulations. When geosmin and 2-MIB in raw was less than 30 ng/L, activated carbon adsorption should be equipped with enhanced coagulations. When thiol and thioether in raw water was more than 20 microg/L, or geosmin and 2-MIB was more than 30 ng/L, ozone-activated carbon process should be added after the conventional water treatment process. When thiol and thioether in raw water was more than 150 microg/L, or geosmin and 2-MIB was more than 100 ng/L, preoxidation or adsorption of powder activated carbon at intake should be combined with ozone-activated carbon according to the odorant composing.