Influence of industrial discharges on the performance and population of a biological nutrient removal process

The study described here concerns the influence of long-term industrial discharges on a biological nutrient removal process. The effects of such discharges were modeled and the effect on the effluent quality and on the population of activated sludge was evaluated. The influent wastewaters used, i.e., urban sewage and industrial discharges, were real wastewaters. A model of the process involving GAO integrated into ASM2d was used for the simulations. For the simulation of the industrial discharges only two parameters needed to be changed and these were the maximum fermentation rate (qfe) and the reduction factor for anoxic activity of PAO (ηNO3)(ηNO3). These changes could be explained in terms of the high biodegradability and the absence of toxic compounds in the studied wastewaters. The industrial discharges were found to have either a positive or negative impact on the nutrient and COD removal. The level of impact was found to depend on the characteristics of the discharge—mainly the VFA, the nitrogen content and the P/COD ratio.