Simultaneous heterotrophic nitrification and aerobic denitrification of wastewater in granular reactor: Microbial composition by next generation sequencing analysis

• DOI: 10.1016/j.jwpe.2020.101254
• Publication Date: 2020-04-24T21:19:37Z
• Authors: Paula Bucci; Bibiana Coppotelli; Irma Morelli; Noemí Zaritzky; Alejandro Caravelli
• Keywords: https://purl.org/becyt/ford/2.8; NEXT-GENERATION SEQUENCING TECHNOLOGY; 0211 other engineering and technologies; MICRONUTRIENTS; DENITRIFICATION; 02 engineering and technology; HETEROTROPHIC NITRIFICATION AND AEROBIC; https://purl.org/becyt/ford/2; CHEESE WHEY; AEROBIC GRANULAR SLUDGE

Abstract Dairy effluents contain limited nitrogen for biological treatment. In the present study a cheese whey wastewater was supplemented with ammonia to obtain suitable COD:N ratios. The effects of the organic load and micronutrients on the biological nitrogen removal process were analyzed in aerobic granular sequential batch reactors (SBRs). Better nitrifying activity (5.04 mg N.(L.h)−1) was achieved at COD:N = 100:12, when micronutrients were added. In this condition, simultaneous nitrification- denitrification led to a higher inorganic nitrogen removal. Aerobic denitrification was driven by intracellular glycogen. In absence of micronutrients, nitrification took place when the organic load was decreased (COD:N = 100:22). The microbial community was analyzed by next-generation sequencing technology. Nitrification was attributed to heterotrophic nitrifiers. Bacteria belonging to Niabella and Diaphorobacter genera and to Planctomycetales order are the main candidates responsible for the nitrification process. Co-treatment of dairy and ammonium-rich wastewater constitutes a promise strategy for the biological treatment of dairy wastewaters.