The activation and extraction systems using organic acids and Lentinus edodes to remediate cadmium contaminated soil

Abstract To develop a high efficient and eco-friendly approach to remediate cadmium (Cd) contaminated soil, we designed the activation and extraction systems, on the basis of combined effects between the ability of organic acids to activate Cd and the ability of mushroom accumulator (Lentinus edodes) to extract Cd. The results showed that the proportion of acetic acid-extractable Cd significant increased with the application of exogenous organic acids. Additionally, soil microecology analysis indicated that exogenous organic acids evidently enhanced the numbers of microbial cells and the activities of soil enzymes. Besides, high throughput sequencing analysis revealed exogenous organic acids improved the diversity and structure of soil bacterial community after remediation. Particularly, the combination application of mushroom and exogenous citric acid had highest accumulation efficiency of Cd, and its efficiency was 59.19% higher than single mushroom treatment. Hence, exogenous organic acids could alleviate soil microecology and increase mycoextraction efficiency, which suggested it was a feasible route to remediate Cd contaminated soil by the activation and extraction systems.