Impact of Biodegradable Organic Matter on the Functional Microbe Activities in Partial Nitrification Granules

Abstract

To explore the short-term impact of biodegradable organic matter on the activities of different functional microbes in autotrophic partial nitrification granular sludge (PNG),the variations of both nitrogen transformation performance and dissolved oxygen (DO) uptake of PNG were investigated in this study,by carrying out successive batch tests with and without the organics stressing.The results showed that the higher the C/N ratio,the lower the specific nitrite accumulation rate of q(NO2--N).Meanwhile,the increase of heterotrophic bacteria (HeB) activities caused the fast DO uptake by PNG,which could effectively suppress nitrite oxidizing bacteria (NOB) with the low oxygen affinity.When inorganic substrate culture was employed in the following phase,both HeB and NOB showed low activities,with significant increase in q(NO2--N).In short,the adverse effects of biodegradable organic matter on the performance of PNG system were partially reversible,which could benefit to enhance the advantage of ammonium oxidizing bacteria (AOB) and improve the stability of partial nitrification reaction.