Journal Article

Mechanisms and microbial structure of partial denitrification with high nitrite accumulation

Li, Baikun, Cao, Shenbin, Du, Rui, Peng, Yongzhen, Niu, Meng, Wang, Shuying

2016

Overview

Nitrite (NO₂ ⁻-N) accumulation in denitrification can provide the substrate for anammox, an efficient and cost-saving process for nitrogen removal from wastewater. This batch-mode study aimed at achieving high NO₂ ⁻-N accumulation over long-term operation with the acetate as sole organic carbon source and elucidating the mechanisms of NO₂ ⁻-N accumulation. The results showed that the specific nitrate (NO₃ ⁻-N) reduction rate (59.61 mg N VSS⁻¹ h⁻¹ at NO₃ ⁻-N of 20 mg/L) was much higher than specific NO₂ ⁻-N reduction rate (7.30 mg N VSS⁻¹ h⁻¹ at NO₃ ⁻-N of 20 mg/L), and the NO₂ ⁻-N accumulation proceeded well at the NO₃ ⁻-N to NO₂ ⁻-N transformation ratio (NTR) as high as 90 %. NO₂ ⁻-N accumulation was barely affected by the ratio of chemical oxygen demand (COD) to NO₃ ⁻-N concentration (C/N). With the addition of NO₃ ⁻-N, NO₂ ⁻-N accumulation occurred and the specific NO₂ ⁻-N reduction rate declined to a much lower level compared with the value in the absence of NO₃ ⁻-N. This indicated that the denitrifying bacteria in the system preferred to use NO₃ ⁻-N as electron acceptor rather than use NO₂ ⁻-N. In addition, the Illumina high-throughput sequencing analysis revealed that the genus of Thauera bacteria was dominant in the denitrifying community with high NO₂ ⁻-N accumulation and account for 67.25 % of total microorganism. This bacterium might be functional for high NO₂ ⁻-N accumulation in the presence of NO₃ ⁻-N.

• Publisher: Springer Berlin Heidelberg,Springer,Springer Nature B.V
• Subject: Accumulation / acetates / Acetates - metabolism / Acetic acid / anaerobic ammonium oxidation / Analysis / Bacteria / Biomedical and Life Sciences / Bioremediation / Biota / Biotechnology / Carbon / Carbon - metabolism / Carbon sources / Chemical oxygen demand / cost effectiveness / Denitrification / Denitrifying bacteria / Environmental Biotechnology / high-throughput nucleotide sequencing / Laboratories / Life Sciences / Microbial Genetics and Genomics / Microbiology / Microorganisms / Next-generation sequencing / nitrate nitrogen / Nitrates / Nitrates - metabolism / nitrite nitrogen / nitrites / Nitrites - metabolism / Nitrogen / Nitrogen dioxide / Nitrogen removal / Nutrients / Organic carbon / Oxidation / Oxidation-Reduction / Reactors / Sequence analysis / Studies / Thauera / Thauera - isolation & purification / Thauera - metabolism / Trace elements / Waste Water - microbiology / Wastewater / Water Pollutants - metabolism