Treatment of anaerobic digested effluent in biochar-packed vertical flow constructed wetland columns: Role of media and tidal operation
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Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
Science of the Total Environment
Abstract
Three types of vertical flow constructed wetland columns (VFCWs), packed with corn cob biochar (CB-CW),
wood biochar (WB-CW) and gravel (G-CW) under tidal flowoperations, were comparatively evaluated to investigate
anaerobic digested effluent treatment performance and mechanisms. Itwas demonstrated that CB-CWand
WB-CWprovide significantly higher removal efficiencies for organic matter (N59%), NH4
+-N (N76%), TN (N37%)
and phosphorus (N71%), compared with G-CW (22%–49%). The higher pollutants removal ability of biocharpacked
VFCWs was mainly attribute to the higher adsorption ability and microbial cultivation in the porous biochar
media. Moreover, increasing the flooded/drained ratio from 4/8 h to 8/4 h of the tidal operation further improved
around 10% of the removal of both organics and NH4
+-N for biochar-packed VFCWs. The phosphorus
removal was dependent on the media adsorption capacities through the whole experiment. However, the
NH4
+-N biodegradation by microbial communities was demonstrated to become the dominant removal mechanismin
the long termtreatment,which compensated the decreased adsorption capacities of the media. The study
supported that the use of biochar would increase the treatment performance and elongate the lifespan of CWs
under tidal operation.
Description
Keywords
High strength wastewater, Microbial community, Nitrogen transformation, Phosphorous removal, Tidal flow constructed wetlands
Citation
Kizito, S., Lv, T., Wu, S., Ajmal, Z., Luo, H., & Dong, R. (2017). Treatment of anaerobic digested effluent in biochar-packed vertical flow constructed wetland columns: role of media and tidal operation. Science of the Total Environment, 592, 197-205. http://dx.doi.org/10.1016/j.scitotenv.2017.03.125