Impacts of water flow on epiphytic microbes and nutrients removal in constructed wetlands dominated by Vallisneria natans with decreasing temperature. (December 2020)

• Record Type: Journal Article
• Authors: Mu, Xiaoying; Zhang, Songhe; Han, Bing; Hua, Zulin; Fu, Dongwang; Li, Ping
• Is Part Of: Bioresource technology. Volume 318(2020)
• Publication Date: 2020-12
• Subjects: Submersed macrophytes -- Biofilms -- Water flow -- Temperature -- Co-occurrence network; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.124058
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Water flow enhanced NH4 + -N and COD removal but inhibited TN and TP removal. Turnover had greater contribution than nestedness to beta-diversity dissimilarity. Bacteria in biofilms were less stable than eukaryotes. The effect of temperature on the bacteria in the biofilm was the main reason for the reduction of purification capacity. Temperature had a greater influence on the microbial community than water flow. Abstract: The mechanisms behind water flow on contaminant removal by a submerged macrophyte-biofilm complex in surface flow wetlands remain to be fully elucidated. In this study, water flow (2.02 ~ 2.12 or 4.06 ~ 4.5 L s −1 ; hydraulic retention time, 7d) significantly enhanced NH4 + -N and COD but inhibited TN and TP removal compared to the static ones. No more than 30% of TN and TP were assimilated by V. natans -biofilm complex in wetland system. Water flow remarkably affected alpha-diversity of microbial community in epiphytic biofilm. As revealed by beta-diversity analysis, turnover played greater contribution to the total dissimilarity than nestedness. Network analyses revealed that the microbial interactions including predation, symbiosis and competition in epiphytic biofilms were much more intensive in the Sept.- Oct. than the Nov.-Dec group. Redundancy and Mantel correlation analyses revealed that temperature played a key role in determining microbial community structure, especially for bacteria.