Combining phytoremediation with soil flushing for arsenic removal from contaminated soil

Arsenic (As) contamination poses a high risk to public health in China. Remediation of soil As contamination is an urgent need. Development of more effective remediation technologies is crucial in order to achieve remediation goals. In this study, pot experiments were carried out to study the As removal effectiveness of planting Pteris vittata L. (P.v.) and Lolium multiflorum L. (L.m.) in combination with in situ soil flushing using monopotassium phosphate (KH₂PO₄) solutions. Results showed that planting P.v. and L.m. in combination with 8 days of KH₂PO₄ solution soil flushing achieved 35.20% and 52.93%. As removal efficiency in the rhizosphere soil, respectively, which was significantly higher than 9.14% removal from soil flushing alone. Results also indicated that planting P.v. and L.m. changed the speciation of As to labile form, facilitating As removal from soil. Growing P.v. with in situ KH₂PO₄ flushing was more effective in remediating As-contaminated agricultural soil; L.m. could not be used in place of P.v to achieve the same remediation efficiency. This research provides an important guidance on plant screening for phytoremediation in combination with in situ flushing to remediate As-contaminated soil.