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dc.contributor.authorBarkle, Gregory F.
dc.contributor.authorSchipper, Louis A.
dc.contributor.authorBurgess, Craig P.
dc.contributor.authorPainter, Brett D.M.
dc.date.accessioned2013-11-21T04:08:34Z
dc.date.available2013-11-21T04:08:34Z
dc.date.copyright2008-01
dc.date.issued2008
dc.identifier.citationBarkle, G. F., Schipper, L. A., Burgess, C. P., & Painter, B. D. M. (2008). In situ mixing of organic matter decreases hydraulic conductivity of denitrification walls in sand aquifers. Ground Water Monitoring & Remediation, 28(1), 57-64.en_NZ
dc.identifier.urihttps://hdl.handle.net/10289/8209
dc.description.abstractIn a previous study, a denitrification wall was constructed in a sand aquifer using sawdust as the carbon substrate. Ground water bypassed around this sawdust wall due to reduced hydraulic conductivity. We investigated potential reasons for this by testing two new walls and conducting laboratory studies. The first wall was constructed by mixing aquifer material in situ without substrate addition to investigate the effects of the construction technique (mixed wall). A second, biochip wall, was constructed using coarse wood chips to determine the effect of size of the particles in the amendment on hydraulic conductivity. The aquifer hydraulic conductivity was 35.4 m/d, while in the mixed wall it was 2.8 m/d and in the biochip wall 3.4 m/d. This indicated that the mixing of the aquifer sands below the water table allowed the particles to re-sort themselves into a matrix with a significantly lower hydraulic conductivity than the process that originally formed the aquifer. The addition of a coarser substrate in the biochip wall significantly increased total porosity and decreased bulk density, but hydraulic conductivity remained low compared to the aquifer. Laboratory cores of aquifer sand mixed under dry and wet conditions mimicked the reduction in hydraulic conductivity observed in the field within the mixed wall. The addition of sawdust to the laboratory cores resulted in a significantly higher hydraulic conductivity when mixed dry compared to cores mixed wet. This reduction in the hydraulic conductivity of the sand/sawdust cores mixed under saturated conditions repeated what occurred in the field in the original sawdust wall. This indicated that laboratory investigations can be a useful tool to highlight potential reductions in field hydraulic conductivities that may occur when differing materials are mixed under field conditions.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoenen_NZ
dc.publisherWileyen_NZ
dc.relation.ispartofGround Water Monitoring & Remediation
dc.relation.urihttp://onlinelibrary.wiley.com/doi/10.1111/j.1745-6592.2007.00185.x/abstracten_NZ
dc.rights© 2008 the author(s).en_NZ
dc.titleIn situ mixing of organic matter decreases hydraulic conductivity of denitrification walls in sand aquifersen_NZ
dc.typeJournal Articleen_NZ
dc.identifier.doi10.1111/j.1745-6592.2007.00185.xen_NZ
dc.relation.isPartOfGround Water Monitoring & Remediationen_NZ
pubs.begin-page57en_NZ
pubs.elements-id32891
pubs.end-page64en_NZ
pubs.issue1en_NZ
pubs.volume28en_NZ


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