Synergistic Remediation of Cd-Contaminated Soil with Pure Natural Adsorption Material and Hyperaccumulator Plant

In recent years, cadmium (Cd) contamination in agricultural soil has emerged as a significant global environmental issue, posing irreversible harm to crops and human health. As a result, efficient soil remediation techniques are urgently needed. For this issue, synergistic remediation by material and plant is an effective approach. In this study, a natural and green adsorption material (starch/montmorillonite composite, SMC) of Cd was prepared, which was further employed in synergistic remediation toward soil Cd contamination with the cadmium hyperaccumulator plant Bidens bipinnata. The results of the pot experiment demonstrated that an available Cd removal rate of 77.92 could be obtained, and the results of the field experiments demonstrate that the concentrations of Cd in contaminated soil could be reduced below the risk-screening values for agricultural land. Further analyses, including a microbial community diversity study, changes in soil BCR fraction components, and a TCLP toxicity leaching experiment, unequivocally elucidated that the synergy of SMC and Bidens bipinnata enhanced the remediation efficiency of Cd in contaminated soil. This study confirmed the application potential of the synergy of SMC and Bidens bipinnata toward Cd-contaminated soil.