Effectiveness evaluation of environmentally friendly stabilizers on remediation of Cd and Pb in agricultural soils by multi-scale experiments

Abstract

Utilizing heavy-metal-contaminated agricultural land safely is an urgent problem. Comprehensive evaluation of remediation efforts and economic benefits of stabilizers on contaminated soil are the most important means to address this problem. Environmentally friendly stabilizers attapulgite (APT), attapulgite/carbon (APT/C), and phosphate mineralization bacteria products (PMBP) were analysed for their ability to stabilize Cd and Pb in soil under incubation conditions and to decrease the uptake of heavy metals by vegetables under greenhouse and field conditions. In incubation, pot, and field experiments, APT/C best stabilized Cd in soil, while PMBP had the best stabilization effect on Pb in soil. Based on effectiveness, cost, and improved yields, the optimal amounts of stabilizers were 5‰ APT/C and 0.21‰ PMBP. In practical applications, PMBP should be appropriately supplemented annually to ensure its efficiency. APT/C and PMBP can be used to treat heavy-metal-contaminated agricultural soils not only in this study area, but also in other similar heavy-metal-contaminated agricultural lands. This study provides a new perspective for evaluating the performance of eco-friendly heavy metal stabilizers in soils by analysing their efficiency, economic benefit, and application time through multiple rounds of multi-scale experiments.