A novel anammox aggregate nourished sustainably internal heterotrophic nitrate removal pathway with endogenous carbon source

• DOI: 10.1016/j.biortech.2021.126525
• Publication Date: 2021-12-09T07:12:13Z
• Authors: Jinyuan Ma; Kaijun Wang; Chuan Shi; Yue Liu; Cheng Yu; Kuo Fang; Xiangyun Fu; Quan Yuan; Yuan Zhou; Hui Gong
• Keywords: Nitrates; Nitrogen; 0211 other engineering and technologies; 02 engineering and technology; Wastewater; Carbon; 6. Clean water; Anaerobic Ammonia Oxidation; 12. Responsible consumption; Bioreactors; Ammonium Compounds; Denitrification; Anaerobiosis; Oxidation-Reduction

Anaerobic ammonium oxidation (anammox) is a cost-effective nitrogen removal pathway but instinctively generated nitrate limits its application. A novel anammox aggregate reduced the production of nitrate significantly with efficient removal of ammonia and nitrite in this work. The results demonstrated that the internal heterotrophic nitrate removal (IHNAR) pathway exists stably at inner of anammox aggregates, which eliminated 42.31 ± 3.85 % nitrate generated in anammox at without consuming external carbon source. The observed volatile fatty acids (VFAs) and adequate protein, polysaccharide and humic acids in the aggregates verified that the in-situ fermentation supplied sustainably endogenous carbon sources for the IHNAR. The efficient interspecies cooperation between anammox bacteria, heterotrophic denitrifiers and fermentative bacteria was identified, as the intrinsic justification for the obtained sustainability of IHNAR pathway. The findings were expected to provide theoretical guidance for promotions and applications of the anammox process with high-efficiency total nitrogen removal capabilities.