A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, school of Environment, Resources and Development

Thesis (M.Sc.) - Asian Institute of Technology, 1980

Bench scale experiments were carried out to study the effect of algae on chlorination of oxidation pond effluents. The experimental results in dicated that the higher chlorine demand was exerted with increasing algae concentration, but algae did not show any apparent effects on the natural die-off of coliform organism upto the 120 minutes contact time. Chlorination affected the concentration of soluble chemical oxygen demand (SCOD) in the pond effluent but the patterns of SCOD changes with time was a complex phenomena. The results of this study indicated that better inactivation rate could be obtained at shorter chlorine contact time, and the bacterial kills were found to decrease with increasing algal concentrations. The magnitude of bacterial kills were proportional to the chlorine dosages, but not with the residual chlorine. The developed kinetic models of bacterial inactivation showed considerable agreement with the experimental data and yielded a correlation coefficient of 0.981. This empirical approach can be used to estimate the bacterial inactivation in oxidation pond effluent under various algae concentrations, chlorine dosages, and contact times used in this study.