Treatment of Nutrient Laden Wastewater Using Simultaneous Nitrification and Denitrification

Abstract

The excess discharge of the untreated wastewater into the natural water bodies stresses the biotic components in it. Discharge of nutrient-rich wastewater into water bodies leads to eutrophication. Simultaneous Nitrification and Denitrification (SND) is a process in which nitrification and denitrification occur simultaneously under microaerobic conditions in a single reactor. Depending upon the microbial community and floc size, the mechanism behind the SND process can change. The creation of stable aerobic and anoxic conditions within the floc is the most tedious process in SND. Slight variation in the dissolved Oxygen (DO) concentration can affect the SND process. Compared to conventional nitrification and denitrification processes, SND is cost-effective due to the decrease in structural footprint, low oxygen requirement, and low energy requirement. This review focuses on the applicability of SND as a clean technology for nutrient removal by investigating the mechanism in detail, factors that affect the process efficiency such as microbial population, DO concentration, Carbon/Nitrogen (C/N) ratio, reactor configurations and thermophysical parameters.