Problems in Obtaining Adequate Sewage Disinfection

Quantitative data are presented concerning the several important factors involved in the wastewater chlorination process. The data indicate that initial mixing of the chlorine solution and the wastewater has a profound effect on process efficiency as measured by the reduction in coliform bacteria. Bacteriological data comparing the reduction of coliform bacteria in stirred batch and backmixed reactors show the effect that the distribution of residence times has on process efficiency. The results indicated that a design criterion based on reactor volume and wastewater flow rate (V/Q) is meaningless. It is recommended that contact basins be designed to approach plug flow reactors. The study results indicate that amperometric chlorine residuals and contact time can be used to predict the efficiency of the wastewater chlorination process when the process design factors affecting initial mixing and residence time distribution functions are ideal.