An activated sludge pilot plant has been operated on a feed consisting of mixtures of domestic and starch plant wastes. The effects of the industrial waste addition on the performance of the biological treatment system have been monitored. Results indicate that the optimal plant performance is obtained with a 1% (V/V) starch waste addition to domestic sewage. It was observed that the addition of the starch plant effluent improved the efficiency of BOD5 removal and also improved settling characteristics of the activated sludge. A shock loading did not affect the plant performance.
The results of the study indicate that it is feasible to combine the treatment of municipal sewage and wheat starch waste in a biological treatment process.