Occurrence of arsenic in ground water in the Choushui River alluvial fan, Taiwan.
An investigation of shallow ground water quality revealed that high arsenic (As) concentrations were found in both aquifers and aquitards in the southern Choushui River alluvial fan of Taiwan. A total of 655 geological core samples from 13 drilling wells were collected and analyzed. High As contents were found primarily in aquitards, to a maximum of 590 mg/kg. The contents were correlated with the locations of the marine sequences. Additionally, strong correlations among the As concentrations of core samples, the clay, and the geological age of the Holocene transgression were identified. Most of the As in ground water originated from the aquitard of the marine sequence. The high As content in marine formations with high clay contents may be attributable to the bioaccumulation of As in the sea organisms, which accrued and were deposited in the formation. A preliminary geogenic model of the origin of the high As concentration in the shallow sedimentary basin of the Choushui River alluvial fan of Taiwan is proposed.
Liu
Chen-Wuing
CW
Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan, 106, ROC. lcw@gwater.agec.ntu.edu.tw
Wang
Sheng-Wei
SW
Jang
Cheng-Shin
CS
Lin
Kao-Hong
KH
D001151:Arsenic / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis; D013058:Mass Spectrometry; D013624:Taiwan; D014874:Water Pollutants, Chemical / Q000032:analysis*
D014874:Water Pollutants, Chemical; D001151:Arsenic