Chlorine Disinfection in Final Settling Basins

by Darrell W. Monroe, Process Engr.; Envir. Equipment Div., FMC Corp., Chicago, IL,
Donald C. Phillips, Assoc. Prof.; Dept. of Civ. Engrg., Oregon State Univ., Corvallis, OR,

Serial Information: Journal of the Sanitary Engineering Division, 1972, Vol. 98, Issue 2, Pg. 287-297

Document Type: Journal Paper


This study was undertaken to provide a comparison between direct chlorination to final settling basins following trickling filters and that of chlorinating settled effluent in a separate contact chamber, the method on which most chlorination standards have been established. The chlorine colicidal efficiencies associated with both settled and unsettled trickling filter effluent were evaluated. The flow characteristics of a circular settling tank were experimentally determined by means of a dye-dispersion test. The standard iodometric and orthtolidine residual chlorine determinations were found to give consistently different results for residual of less than 5 mg/l. Chlorine dosages of 2 mg/l and greater gave complete coliform disinfection (less than 0.001% remaining) for both settled and unsettled samples in less than 3 hrs of contact. The difference between the colicidal efficiency of chlorine in the settled samples and that in the unsettled samples was found to decrease with increased chlorine dosages and became insignificant at dosages of 4 mg/l and greater.

Subject Headings: Chlorine | Disinfection | Settling basins | Comparative studies | Filters | Effluents | Sedimentation tanks | Cylindrical tanks

Services: Buy this book/Buy this article


Return to search