Study on Anaerobic Treatment of Synthetic Milk Wastewater under Variable Experimental Conditions

Abstract

This paper is concerned with the investigation of various phases of the anaerobic treatment of synthetic milk wastewater under variable experimental conditions. The dairy industry wastewaters contain high concentrations of organic matter and therefore requires proper treatment prior to discharge. There is, however, lack of experimental data available for the various important temperature ranges (psychophillic, mesophilic, thermophilic) and other parameters like organic loading rate and retention time. The investigation has been made to comprehend the degree of wastewater stabilization in terms of COD at variable temperature, organic loads and retention times, with and without providing additional seeds for the treatment in the batch reactor. The study is focused on finding out the optimal parameters for efficient biodegradation of organics in the milk wastewaters. These experiments have been performed in a baffled anaerobic batch reactor. Experimental results show that the percentage COD reduction increases with time for all the considered cases. The organic loading affects the COD reduction significantly. The percentage COD reduction at 35 0 C without additional seeds, has been observed at the lower organic loading 1g/l and retention time of 72 h to be 50.00%. Whereas the COD reduction is 83.33% with seeds, under same conditions. As organic loading increases, the percentage COD reduction decreases; a phenomenon that has been observed in all the temperature ranges. The three different peaks of percentage COD reduction have been found out at the above mentioned temperature ranges for both with and without seeds cases.