Role of heterotrophic nitrifiers and aerobic denitrifiers in simultaneous nitrification and denitrification process: a nonconventional nitrogen removal pathway in wastewater treatment. (19th October 2021)

• Record Type: Journal Article
• Authors: Gupta, R.K.; Poddar, B.J.; Nakhate, S.P.; Chavan, A.R.; Singh, A.K.; Purohit, H.J.; Khardenavis, A.A.
• Is Part Of: Letters in applied microbiology. Volume 74:Number 2(2022)
• Page Start: 159
• Page End: 184
• Publication Date: 2021-10-19
• Subjects: bioprocess optimization -- heterotrophic nitrification‐aerobic denitrification -- nitrogen pollution -- wastewater treatment; Microbiology -- Periodicals; 660.62
• DOI: 10.1111/lam.13553
• Languages: English
• ISSNs: 0266-8254

Abstract

Abstract: Bacterial species capable of performing both nitrification and denitrification in a single vessel under similar conditions have gained significance in the wastewater treatment scenario considering their unique character of performing the above reactions under heterotrophic and aerobic conditions respectively. Such a novel strategy often referred to as simultaneous nitrification and denitrification (SND) has a tremendous potential in dealing with various wastewaters having low C : N content, considering that the process needs very little or no external carbon source and oxygen supply thus adding to its cost‐effective and environmentally friendly nature. Though like other micro‐organisms, heterotrophic nitrifiers and aerobic denitrifiers convert inorganic or organic nitrogen‐containing substances into harmless dinitrogen gas in the wastewater, their ecophysiological role in the global nitrogen cycle is still not fully understood. Attempts to highlight the role played by the heterotrophic nitrifiers and aerobic denitrifiers in dealing with nitrogen pollution under various environmental operating conditions will help in developing a mechanistic understanding of the SND process to address the issues faced by the traditional methods of aerobic autotrophic nitrification–anaerobic heterotrophic denitrification. Abstract : Significance and Impact of the Study: The review highlights the significance of a novel but nonconventional mode for managing high nitrogen wastewater loaded with different nitrogen species (NH4 + ‐N, NO3 − ‐N, NO2 − ‐N). The treatment strategy can tackle the excess nitrogen under low C:N ratio and dissolved oxygen conditions by simultaneous nitrification and denitrification thus making it a cost‐effective and environment‐friendly process. The treatment is achieved by virtue of a diverse group of micro‐organisms that perform aforesaid reactions under heterotrophic and aerobic conditions respectively in a single reactor. The review attempts to develop a mechanistic understanding about their ecophysiological role in the global nitrogen cycle for large‐scale applications.