Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
2007-5-22
pubmed:abstractText
Groundwater with high concentration of geogenic arsenic (As) occurs extensively in the Holocene alluvial aquifers of Bangladesh. Local drillers in Matlab Upazilla are constructing deeper tubewells than in the recent past, primarily because of low concentrations of dissolved Fe and As. Locally a thick layer of black to grey sediments overlies an oxidised unit of yellowish-grey to reddish-brown sediments. The correlation between the colour of both units and the groundwater redox conditions was investigated to provide an easy tool for targeting low-arsenic groundwater. Based on the sediment colour at the screen depths described by local drillers, 40 domestic shallow tubewells were selected for water sampling. Four colours were used to describe the sediments: black, white, off-white (buff) and red. Generally, the groundwater was anoxic and the As concentrations ranged from less than 5.2 to 355 microg/L. Water derived from the black sediment is characterized by relatively higher concentrations of dissolved NH(4)(+), DOC, Fe, P, As and by low Mn and SO(4)(2-) concentrations. The off-white and red sediments had high concentration of Mn and low NH(4)(+), DOC, Fe, P and As concentrations. The water abstracted from the black sediments indicated the most reducing environment, followed by white, off-white and red respectively. Three boreholes verified the driller's perception of the subsurface lithologic conditions. Discrepancies between the driller's and the research team description of the sediment colours were insignificant. This study shows that sediment colour is a reliable indicator of high and low-As concentrations and can be used by local drillers to target low-arsenic groundwater.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0048-9697
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
379
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
121-32
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Targeting low-arsenic aquifers in Matlab Upazila, Southeastern Bangladesh.
pubmed:affiliation
KTH-International Groundwater Arsenic Research Group, Department of Land and Water Resources Engineering, Royal Institute of Technology, SE-100 44 Stockholm, Sweden. mnb@kth.se
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't