Primary sink and source of geogenic arsenic in sedimentary aquifers in the southern Choushui River alluvial fan, Taiwan

Kuang Liang Lu, Chen Wuing Liu, Sheng Wei Wang, Cheng Shin Jang, Kao Hung Lin, Vivian Hsiu Chuan Liao, Chung Min Liao, Fi John Chang

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River alluvial fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO3- and NH4+ concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO43 - and HCO3- along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.

Original languageEnglish
Pages (from-to)684-695
Number of pages12
JournalApplied Geochemistry
Volume25
Issue number5
DOIs
Publication statusPublished - 2010 May 1

All Science Journal Classification (ASJC) codes

  • Environmental Chemistry
  • Pollution
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Primary sink and source of geogenic arsenic in sedimentary aquifers in the southern Choushui River alluvial fan, Taiwan'. Together they form a unique fingerprint.

Cite this