Denitrification with non-organic electron donor for treating low C/N ratio wastewaters

• Published in: Bioresource technology Vol. 299; p. 122686
• Main Authors: Tian, Tian, Yu, Han-Qing
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2020
• Subjects: Autotrophic; Autotrophic Processes; Bioreactors; Denitrification; Electrons; Ferrous ions; Hydrogen; Nitrates; Nitrogen; Reduced sulfur compounds; sulfur; Waste Water; Wastewater; wastewater treatment; Denitrification; Reduced sulfur compounds; Wastewater; Hydrogen; Ferrous ions; Autotrophic
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2019.122686

•Main non-organic electron donors for low C/N wastewater denitrification are summarized.•Autotrophic denitrification processes for treating low C/N wastewater are highlighted.•Concerns about their potential adverse impacts in practical applications are discussed.•Combined denitrification processes for multi-contaminant removals are envisaged. Denitrification with non-organic electron donors for treating low C/N ratio wastewater has attracted growing interests. Hydrogen, reduced sulfur compounds and ferrous ions are mainly used in autotrophic denitrification, holding promise for achieving practical applications. Recently, the development of autotrophic denitrification-based processes, such as bioelectrochemically-supported hydrogenotrophic denitrification and sulfur-/iron-based denitrification assisted multi-contaminant removal, provide opportunities for applying these processes in wastewater treatment. Exploration of the autotrophic denitrification process in terms of contaminant removal mechanism, interaction among functional microorganisms, and potential full-scale applications is thus of great importance. Here, an overview of the commonly used non-organic electron donors, e.g., hydrogen, reduced sulfur compounds and ferrous ions, in denitrification for treating low C/N ratio wastewater is provided. Also, the feasibility of applying the combined processes based on autotrophic denitrification with the compounds is discussed. Furthermore, challenges and future possibilities as well as concerns about the practical applications are envisaged in this review.