Establishment and convergence of photosynthetic microbial biomats in shallow unit process open-water wetlands.

Autor: Jones ZL; ReNUWIt Engineering Research Center, United States; Department of Civil & Environmental Engineering, Hydrologic Science & Engineering Program, Colorado School of Mines, Golden, CO 80401, United States., Mikkelson KM; ReNUWIt Engineering Research Center, United States; Department of Civil & Environmental Engineering, Hydrologic Science & Engineering Program, Colorado School of Mines, Golden, CO 80401, United States., Nygren S; ReNUWIt Engineering Research Center, United States; Orange County Water District, Fountain Valley, CA 92708, United States., Sedlak DL; ReNUWIt Engineering Research Center, United States; Department of Civil & Environmental Engineering, University of California at Berkeley, Berkeley, CA 94720, United States., Sharp JO; ReNUWIt Engineering Research Center, United States; Department of Civil & Environmental Engineering, Hydrologic Science & Engineering Program, Colorado School of Mines, Golden, CO 80401, United States. Electronic address: jsharp@mines.edu.
Jazyk: angličtina
Zdroj: Water research [Water Res] 2018 Apr 15; Vol. 133, pp. 132-141. Date of Electronic Publication: 2018 Jan 10.
DOI: 10.1016/j.watres.2018.01.021
Abstrakt: The widespread adoption of engineered wetlands designed for water treatment is hindered by uncertainties in system reliability, resilience and management associated with coupled biological and physical processes. To better understand how shallow unit process open-water wetlands self-colonize and evolve, we analyzed the composition of the microbial community in benthic biomats from system establishment through approximately 3 years of operation. Our analysis was conducted across three parallel demonstration-scale (7500 m 2 ) cells located within the Prado Constructed Wetlands in Southern California. They received water from the Santa Ana River (5.9 ± 0.2 mg/L NO 3 -N), a water body where the flow is dominated by municipal wastewater effluent from May to November. Phylogenetic inquiry and microscopy confirmed that diatoms and an associated aerobic bacterial community facilitated early colonization. After approximately nine months of operation, coinciding with late summer, an anaerobic community emerged with the capability for nitrate attenuation. Varying the hydraulic residence time (HRT) from 1 to 4 days the subsequent year resulted in modest ecological changes across the three parallel cells that were most evident in the outlet regions of the cells. The community that established at this time was comparatively stable for the remaining years of operation and converged with one that had previously formed approximately 550 km (350 miles) away in a pilot-scale (400 m 2 ) wetland in Northern California. That system received denitrified (20.7 ± 0.7 mg/L NO 3 -N), secondary treated municipal wastewater for 5 years of operation. Establishment of a core microbiome between the two systems revealed a strong overlap of both aerobic and anaerobic taxa with approximately 50% of the analyzed bacterial sequences shared between the two sites. Additionally the same species of diatom, Stauirsa construens var. venter, was prolific in both systems as the putative dominant primary producer. Our results indicate that despite differences in scale, geographic location and source waters, the shallow open-water wetland design can select for a rapid convergence of microbial structure and functionality associated with the self-colonizing benthic biomat. This resulting biomat matures over the first growing season with operational parameters such as HRT further exerting a modest selective bias on community succession.
(Copyright © 2018 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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