Use of industrial wastewaters for the optimization and control of nitrogen removal processes

In this experimental study the characterization of 2 industrial wastewaters, coming from an ice cream production industry (IW1) and a beet-sugar factory (IW2), with respect to their readily biodegradable fraction and denitrification potential, has been performed. To this end physical-chemical and biological characterization methods, both anoxic and aerobic, were used. Moreover a pilot scale SBR fed with municipal wastewater was started to verify the effect of the gradual addition of the concentrated organic wastewaters during the anoxic phase. The SBR was initially fed only with a primary municipal wastewater, then the organic load was increased by adding to the feed, during the anoxic phase, a small amount of the IW1 (second period). Once the initial conditions were restored the load was again raised using the second industrial wastewater (IW2) (third period). With those additions the nitrogen removal efficiency increased from 26% to 50%, in the case of the IW1 and from 23% to 53% in the case of the wastewater IW2, without any negative effect on the global performance of the system. In addition, periodical kinetic studies of denitrification and nitrification in the SBR, were performed.