Community level physiological profiling of microbial electrochemical-based constructed wetlands

• Published in: The Science of the total environment Vol. 721; p. 137761
• Main Authors: Ramírez-Vargas, Carlos A., Arias, Carlos A., Zhang, Liang, Paredes, Diego, Brix, Hans
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-06-2020
• Subjects: CLPP; CSUP; Electroactive bacteria; METland; Microbial electrochemical technologies; Treatment wetlands; CSUP; Electroactive bacteria; Microbial electrochemical technologies; Treatment wetlands; CLPP; METland
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.137761

The performance of constructed wetlands (CW) can be enhanced through the use of microbial electrochemical technologies like METland systems. Given its novelty, uncertainties exist regarding processes responsible for the pollutant removal and microbial activity within the systems. Genetic characterization of microbial communities of METlands is desirable, but it is a time and resource consuming. An alternative, is the functional analysis based on community-level physiological profile (CLPP), which allows to evaluate the diversity of microbial communities based on the carbon consumption patterns and derived indexes (average well color development – AWCD –, richness, and diversity). This study aimed to characterize the microbial community function of laboratory-scale METlands using the CLPP method. It encompassed the analysis of planted and non-planted set-ups of two carbon-based electroconductive materials (Coke-A and Coke-LSN) colonized with electroactive biofilms, and compared to Sand-filled columns. Variations in the microbial metabolic activity were found to depend on the characteristics of the material rather than to the presence of plants. Coke-A systems showed lower values of AWCD, richness, and diversity than Sand and Coke-LSN systems. This suggests that Coke-A systems provided more favorable conditions for the development of relatively homogeneous microbial biofilms. Additionally, typical parameters of water quality were measured and correlations between utilization of carbon sources and removal of pollutants were established. The results provide useful insight into the spatial dynamics of the microbial activity of METland systems.
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•CLPP allows describing the microbial spatial dynamics of METland systems.•Microbial metabolic activity of METlands is influenced by support material.•METlands with Coke-A had lower values of AWCD, richness and diversity than control.•Coke-A provided conditions to develop homogeneous microbial biofilms.•The consumption of carbon guilds was associated with the removal efficiencies.