Enhanced mobilization of arsenic from tailing soil by four types of low molecular weight organic acids with different functional groups

Purpose 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. Materials and methods 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. Results and discussion In the batch experiment, the LMWOA enhancement of arsenic migration was in the order of 3-mercaptopropionic acid > aspartic acid > succinic acid > propionic 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. Conclusions 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.

Automated summary

The study aimed to enhance arsenic migration in contaminated soil using low molecular weight organic acids. It was found that 3-mercaptopropionic acid was the most effective in accelerating arsenic migration, leaching out 247.29 mg/kg of arsenic in 48 hours and releasing 21.02% of arsenic after 75 hours in column experiments.