TY - JOUR
T1 - Characterisation of organic matter associated with groundwater arsenic in reducing aquifers of southwestern Taiwan
AU - Al Lawati, Wafa M.
AU - Jean, Jiin Shuh
AU - Kulp, Thomas R.
AU - Lee, Ming Kuo
AU - Polya, David A.
AU - Liu, Chia Chuan
AU - Van Dongen, Bart E.
N1 - Funding Information:
WAL gratefully acknowledges receipt of a PhD studentship funded by the Ministry of Manpower, Sultanate of Oman . JSJ thank the National Science Council of Taiwan to provide financial support for drilling in Yichu (Grant number NSC97-2627-M-006–003 ). We thank Jyoti Maity, Sandeep Kar, Golam Mostafa and Selim Reza for their help in sampling of groundwater and core sediments at the Yichu drilling site, and Paul Lythgoe for his invaluable assistance with the GC–MS analyses.
PY - 2013/11/15
Y1 - 2013/11/15
N2 - Arsenic (As) in groundwaters extensively used by people across the world constitutes a serious public health threat. The importance of organic matter (OM) as an electron donor in microbially-mediated reduction of As(V) or Fe(III)-bearing As-host minerals leading to mobilisation of solid-phase arsenic is widely recognised. Notwithstanding this, there are few studies characterising OM in such aquifers and, in particular, there is a dearth of data from the classic arsenic bearing aquifers in southwestern Taiwan. Organic geochemical analyses of sediments from a known groundwater arsenic hot-spot in southwestern Taiwan revealed contributions of thermally mature and plant derived origin, consistent with OM sources in all other Asian groundwater aquifer sediments analysed to date, indicating comparable sources and routes of OM transfer. The combined results of amended As(V) reduction assays with the organic geochemical analysis revealed that the microbiological process of dissimilatory As(V) reduction is active in this aquifer, but it is not controlled by a specific source of analysed OM. These indicate that (i) part of the OM that was considered to be less bio-available could still be used as an electron donor or (ii) other electron donors, not analysed in present study, could be controlling the rate of As release.
AB - Arsenic (As) in groundwaters extensively used by people across the world constitutes a serious public health threat. The importance of organic matter (OM) as an electron donor in microbially-mediated reduction of As(V) or Fe(III)-bearing As-host minerals leading to mobilisation of solid-phase arsenic is widely recognised. Notwithstanding this, there are few studies characterising OM in such aquifers and, in particular, there is a dearth of data from the classic arsenic bearing aquifers in southwestern Taiwan. Organic geochemical analyses of sediments from a known groundwater arsenic hot-spot in southwestern Taiwan revealed contributions of thermally mature and plant derived origin, consistent with OM sources in all other Asian groundwater aquifer sediments analysed to date, indicating comparable sources and routes of OM transfer. The combined results of amended As(V) reduction assays with the organic geochemical analysis revealed that the microbiological process of dissimilatory As(V) reduction is active in this aquifer, but it is not controlled by a specific source of analysed OM. These indicate that (i) part of the OM that was considered to be less bio-available could still be used as an electron donor or (ii) other electron donors, not analysed in present study, could be controlling the rate of As release.
UR - http://www.scopus.com/inward/record.url?scp=84887607712&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84887607712&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2012.08.007
DO - 10.1016/j.jhazmat.2012.08.007
M3 - Article
C2 - 22964390
AN - SCOPUS:84887607712
VL - 262
SP - 970
EP - 979
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
SN - 0304-3894
ER -