| In-stream bioreactor for agricultural nitrate treatment. | |
| | |
MedLine Citation:
|
PMID: 19141813 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Nitrate from agricultural activity contributes to nutrient loading in surface water bodies such as the Mississippi River. This study demonstrates a novel in-stream bioreactor that uses carbonaceous solids (woodchips) to promote denitrification of agricultural drainage. The reactor (40 m3) was trenched into the bottom of an existing agricultural drainage ditch in southern Ontario (Avon site), and flow was induced through the reactor by construction of a gravel riffle in the streambed. Over the first 1.5 yr of operation, mean influent NO3-N of 4.8 mg L(-1) was attenuated to 1.04 mg L(-1) at a mean reactor flow rate of 24 L min(-1). A series of flow-step tests, facilitated by an adjustable height outlet pipe, demonstrated that nitrate mass removal generally increased with increasing flow rate. When removal rates were not nitrate-limited, areal mass removal ranged from 11 mg N m(-2) h(-1) at 3 degrees C to 220 mg N m(-2) h(-1) at 14 degrees C (n = 27), exceeding rates reported for some surface-flow constructed wetlands in this climatic region by a factor of about 40. Over the course of the field trial, reactor flow rates decreased as a result of silt accumulation on top of the gravel infiltration gallery. Design modifications are currently being implemented to mitigate the effects of siltation. In-stream reactors have the potential to be scaled larger and could be more manageable than attempting to address nitrate loading from individual tile drains. They could also work well in combination with other nitrate control techniques. |
| | |
Authors:
|
W D Robertson; L C Merkley |
Related Documents
:
|
8931283 - Transcranial doppler sonographic measurements of middle cerebral artery flow velocity d... 15328783 - Dysbaric osteonecrosis screening in submarine escape instructors. 11021333 - Hyperdynamic circulation in portal hypertension: a comparative model of arterio-venous ... |
Publication Detail:
|
Type: Journal Article Date: 2009-01-13 |
Journal Detail:
|
Title: Journal of environmental quality Volume: 38 ISSN: 0047-2425 ISO Abbreviation: J. Environ. Qual. Publication Date: 2009 Jan-Feb |
Date Detail:
|
Created Date: 2009-01-14 Completed Date: 2009-03-10 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0330666 Medline TA: J Environ Qual Country: United States |
Other Details:
|
Languages: eng Pagination: 230-7 Citation Subset: IM |
Affiliation:
|
Dep. of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada. wroberts@sciborg.uwaterloo.ca |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Agriculture* Bioreactors* Nitrates / isolation & purification* Seasons Waste Disposal, Fluid / methods Water / analysis Water Movements Water Pollutants, Chemical / isolation & purification* Water Pollution, Chemical / prevention & control* |
| Chemical | |
Reg. No./Substance:
|
0/Nitrates; 0/Water Pollutants, Chemical; 7732-18-5/Water |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Rainfall simulation in greenhouse microcosms to assess bacterial-associated runoff from land-applied...
Next Document: Toxicity of anionic polyacrylamide formulations when used for erosion control in agriculture.