The effluent from conventional nightsoil treatment plants contains nutrients, color and chlorides, in addition to residual organics and suspended solids, and thereby causes substantial pollution problems in receving water resources. In order to verify the usefullness of electrolysis in removing those residual pollutants from such conventional nightsoil treatment plant effluent, a bench scale experiment was conducted using sufficiently dilluted human nightsoil as experiment feeds. The result showed mean removals of 45% of total phosphorus and 85% of color, in addition 87% of residual BOD, 47% of residual COD and 85% of residual SS. The optimum electric current was found to be 15 ampere and the optimum hydraulic residence time 21/2 hour.

The present study was performed to develop the removal system of the offensive gases, including hydrogen sulfide of acid gas, ammonia or amine of base gas, from the nightsoil treatment plant. In order to remove the offensive gases, the Fe-EDTA system liquid phase catalytic oxidation method with the bubble lift column reactor was employed. From the results obtained it was confirmed that the offensive gases can be deodorized simultaneously and also hydrogen sulfide of acid gas, ammonia of base gas completely removed at pH 6.45. In addition, as input gases feed rate the efficiency of acid gas did not change but the efficiency of base gases decreased to approximately 90% at pH 6.0. From the result of particle size analyzer, it was found that the particle sizes including sulfur and other impurites grew up to 21μm over 72hour reaction time.