HR: 13:40h
AN: H13L-01    [Abstracts]
TI: Arsenic and Humic Substances in Alluvial Aquifers of Bangladesh and Taiwan: A Comparative Study
AU: * Reza, A
EM: sreza69@yahoo.com
AF: Department of Earth Sciences, National Cheng Kung University, No.1, Ta-Hsueh Rd, Tainan, 701, Taiwan
AU: Jean, J
EM: jiinshuh@mail.ncku.edu.tw
AF: Department of Earth Sciences, National Cheng Kung University, No.1, Ta-Hsueh Rd, Tainan, 701, Taiwan
AU: Lee, M
EM: leeming@auburn.edu
AF: Department of geology and Geography, Auburn University, Auburn, Auburn, AL 36849, United States
AB: Humic substances in groundwater samples from the arsenicosis area in Bangladesh, northern Taiwan and the Blackfoot disease (BFD) area in southwestern Taiwan were characterized by Fluorescence Spectroscopy (FS), and Fourier Transform Infrared Spectroscopy (FTIR) analyses. As, Mn, Fe, Sr, Se levels in these groundwaters were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Major ions and selected water parameters including pH, electrical conductivity (EC), oxidation reduction potential (ORP), and dissolved oxygen (DO) were also determined. Groundwater As concentration ranges from 1.4 to 140 μg/L in the alluvial aquifers located in the Chapai-Nawabganj district of Bangladesh. As levels in groundwater ranges from 0.5 to 560 μg/L in the Ilan Plain of northern Taiwan. Geothermal waters in the Beitou hot springs contain high concentrations of inorganic As (up to 3,975 μg/L); geothermal activity is likely responsible for the significant discharge of arsenic to the downstream Kwandu Plain. As levels in the BFD area of southwestern Taiwan ranges from 25 μg/L to 967 μg/L. Interestingly, groundwater arsenic in the BFD area of southwestern Taiwan correlates positively with strong fluorescence (maximum relative fluorescence intensity upto 495) and the content of humic substances. In contrast, As-rich groundwaters from Chapai-Nawabganj district of Bangladesh and northern part of Taiwan generally have relatively low content of humic substances with weak fluorescence (maximum relative fluorescence intensity upto 65 and 121, respectively). Moreover, results of FTIR analysis show that humic substances extracted from water samples of the Taiwan BFD area contain phenolic and amines groups of humic substances, which tend to form organo-metal complexes with As and other trace elements. High levels of As and humic substances probably play a critical role in causing the Black foot disease in Chia-Nan plain of southwestern Taiwan.
DE: 1831 Groundwater quality
SC: Hydrology [H]
MN: 2007 Fall Meeting