Enhancement of facultative anaerobic denitrifying communities by oxygen release from roots of the macrophyte in constructed wetlands. (15th September 2019)

• Record Type: Journal Article
• Authors: Sun, Haishu; Xu, Shengjun; Wu, Shanghua; Wang, Rui; Zhuang, Guoqiang; Bai, Zhihui; Deng, Ye; Zhuang, Xuliang
• Is Part Of: Journal of environmental management. Volume 246(2019)
• Page Start: 157
• Page End: 163
• Publication Date: 2019-09-15
• Subjects: Constructed wetland -- Nitrogen removal -- Root oxygen release -- Facultative anaerobic niches -- Denitrifying communities; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.05.136
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The radial oxygen loss (ROL) of wetland plants is a crucial factor that can influence the efficiency required for nitrogen (N) removal and microbial activities responsible for N removal in constructed wetlands (CWs). However, the shift of microbial community in different niches in response to ROL has been rarely studied. This study aims to unravel the link between the ROL and microbial response in sediment, water and rhizoplane by a surface flow CW planted with Myriophyllum aquaticum for treating high-strength swine wastewater. Ti 3+ -citrate colorimetric method demonstrated that M. aquaticum was a wetland species with a ROL of 0.019 mg/h/plant. Using quantitative polymerase chain reactions (qPCR) and high-throughput sequencing of microbial 16S rRNA gene, we demonstrated that the abundance of facultative anaerobic denitrifiers in the rhizoplane was the most of the three niches, that in the water (5–10 cm) was the less and that in the sediment was the least. Acinetobacter was enriched and dominated amongst denitrifiers in the water. Denitrifiers in the rhizoplane were mainly dominated by enriched Pseudomonas, Aeromonas, and Acinetobacter . The theoretical calculation of oxygen sources and consumptions indicated that water reaeration should support the oxygen demands for nitrification in the aerobic layer (0–5 cm), and the ROL could stimulate the growth of facultative anaerobic denitrifiers in the rhizoplane and water (5–10 cm) to achieve denitrification within CW systems. Graphical abstract: Image 1 Highlights: ROL from roots of the M. aquaticum was 0.019 mg/h/plant. Facultative anaerobic denitrifiers were enriched in the rhizoplane and water. Water reaeration should support the oxygen for nitrification in the aerobic layer. ROL could create facultative anaerobic microsites for denitrification.