Denitrifying bioreactors are increasingly being used for nitrate removal from agricultural drainage water. Filled with carbon substrates, often woodchips, denitrifying bioreactors provide a favorable anaerobic environment for denitrification. Despite performing well in loess soils in the Midwestern United States, field bioreactors have not yet been evaluated in shallow soils over glacial till that are characteristic for the Northeastern United States. This study, therefore, investigates the performance of bioreactors and provides design criteria for shallow soil with flashy discharges. Paired bioreactors, one filled with woodchips and one with a mixture of woodchip and biochar, were installed in tile drained fields in three landscapes in New York State. The bioreactors were monitored for a three-year period during which, the flow rate, temperature, nitrate (NO-N), sulfate (SO-S) and dissolved organic carbon (DOC) were measured. Results showed that the average NO-N removal efficiency during the three years of observations was about 50%. The NO-N removal rate ranged from 0 in winter to 72 g d m in summer. We found that biochar was only effective during the first year in enhancing denitrification, due to the ageing. An index for carbon availability related to NO-N removal was developed. During winter, availability of the DOC was a limiting factor in bioreactor performance. Finally, to aid in the design of bioreactors, we developed generalizable relationships between the removal efficiency and hydraulic retention time and temperature.
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http://dx.doi.org/10.1016/j.jenvman.2017.06.054 | DOI Listing |
J Nat Resour Agric Ecosyst
January 2024
Office of Research and Development, USA Environmental Protection Agency, Research Triangle Park, North Carolina, USA.
J Environ Manage
December 2024
Department of Crop Sciences, University of Illinois at Urbana-Champaign, AW-101 Turner Hall, 1103 South Goodwin Avenue, Urbana, IL, USA. Electronic address:
Pumping surface water from a ditch into a denitrifying woodchip bioreactor could improve nitrate-nitrogen (N) removal by minimizing flow variabilities such as early flow cessation at a given subsurface drainage outlet and flashy drainage hydrographs. Few field-scale subsurface drainage bioreactors with pumping configurations have been assessed. Such evaluations would help better bound reasonable expectations of the benefits and drawbacks at these more advanced bioreactors.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Key Laboratory of Environmental Pollution Control Technology Research of Zhejiang Province, Eco-environmental Science Research & Design Institute of Zhejiang Province, Hangzhou, 310007, China.
Chemosphere
December 2024
Australian Centre for Water and Environmental Biotechnology (ACWEB, Formerly AWMC), Gehrmann Building, The University of Queensland, St. Lucia, 4072, Brisbane, Australia.
Within this research, a one-stage hybrid dual internal circulation airlift A2O (DCAL-A2O) bioreactor was designed and operated to simultaneously remove carbon, nitrogen and phosphorous (CNP) from milk processing wastewater (MPW) in different operational circumstances. The substantial operating variables monitored in this work were including hydraulic retention time (HRT), airflow rate (AFR) and aeration volume ratio (AVR) ranged from 7 to 15 h, 1-3 L/min and 0.324-0.
View Article and Find Full Text PDFHuan Jing Ke Xue
December 2024
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
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