Options for the Rational Design and Operation of Oxidation Ponds

Abstract

Oxidation ponds can degrade wastewaters at low cost and provide a useful biomass if rational design, operation, and sludge removal practices are carried out. Here, the design of a plug flow Algal Bacterial Clay Treatment System (ABCT) is presented on the bases of both incident sunlight and incoming BOD concentration. Results of kinetic experimental studies are presented in order to determine both optimal and limiting operational parameters. From these experiments, it appeared to be critical to limit pH diurnal variations for effective operation of the treatment system. Empirical computer models were developed to predict reactor parameter variations due to diurnal effects. A computer model based on continuous oxidation reduction potential (redox) measurements appeared to be most useful for automated computer control of variations due to diurnal effects. Chemical addition of CaCl2 facilitated algal biomass flocculation in order to prepare liquid effluents for plant discharge and to prepare biomass for possible beneficial use.