Journal of Soils and Sediments | 2021
Enhanced mobilization of arsenic from tailing soil by four types of low molecular weight organic acids with different functional groups
Abstract
Increasing the migration of arsenic in contaminated soil is an important topic in the field of soil remediation. The purpose of this study was to investigate the enhancement of arsenic migration in soil by low molecular weight organic acids. Four different low molecular weight organic acids were used to wash the soil to increase arsenic mobility under different experimental conditions, including the type of LMWOA, reaction time, and pH. The arsenic fractions in the soil were further quantitated and analyzed. In the batch experiment, the LMWOA enhancement of arsenic migration was in the order of 3-mercaptopropionic acid\u2009>\u2009aspartic acid\u2009>\u2009succinic acid\u2009>\u2009propionic acid. At pH 11, 247.29 mg/kg arsenic was leached from the soil with 3-mercaptopropionic acid over 48 h. This was confirmed in column experiments where 3-mercaptopropionic acid was also the most effective, releasing 21.02% of the arsenic after 75 h. This suggests that the sulfhydryl group of 3-mercaptopropionic acid was superior to other groups in accelerating arsenic migration. These results enhance our understanding of the interaction between arsenic migration and organic acid functional groups and have applications for the development of soil remediation technology.