Pedogeochemical distribution of gallium, indium and thallium, their potential availability and associated risk in highly-weathered soil profiles of Taiwan
Journal
Environmental Research
Journal Volume
197
Date Issued
2021
Author(s)
Abstract
Gallium (Ga), indium (In), and thallium (Tl) are emerging soil contaminants. Profile distribution of total content and available form as well as assessing the contamination degree of these elements in highly-weathered soils have not been studied. Consequently, the aim of this study was to determine the distribution of total (HF-digestion) and available (EDTA-extracted form) content of Ga, In, and Tl in eleven soil profiles collected from aged fluvial materials on the Quaternary terraces representing highly-weathered soils (Ultisols and Oxisols) in Taiwan as affected by soil properties. We also assessed the soils contamination degree using indices including enrichment factor (EF), geo-accumulation index (Igeo), and pollution loading index (PLI). The total element content varied from 9460 to 2340 μg kg?1 for Ga, 4.77–37.1 μg kg?1 for In, and from 55.7 to 206 μg kg?1 for Tl. The elements showed different profile distribution in the soils. Soil contamination degree was low in all profiles according to the Igeo and PLI values, but the contamination degree according to the EF was severe for Ga and minor or moderate for In in selected horizons of some profiles. The median content of EDTA-extracted Ga, In, and Tl accounted for 24.0, 8.70, and 5.1% of the total content, respectively. The available Ga and Tl can be predicted by a function of total element and clay using multivariate linear regression analysis. The available In was not able to be predicted by a significant fit of the regression with total In and the studied soil properties, and thus we require more assessment approaches of In availability for the soils in the future. ? 2021 Elsevier Inc.
Subjects
edetic acid; gallium; indium; thallium; extraction method; gallium; geochemical survey; indium; risk assessment; soil pollution; thallium; weathering; Article; extraction; geoaccumulation index; linear regression analysis; multiple linear regression analysis; priority journal; soil erosion; soil property; Taiwan; weathering; Taiwan
Type
journal article