Systematic analysis of the applicability and mechanism of three soil conditioners for the paddy soil contaminated by electronic waste dismantling

Abstract

E-waste dismantling has induced the surrounding farmland subjected to combined contamination of heavy metals (HMs) and organic pollutants. At present, applicable regimes for safety production of the contaminated paddy soils and involving mechanisms are still unclear. Here, we investigated the effects of three soil conditioners (lime, biochar, and fengshouyan) on paddy soil ecosystem. Results showed that lime amendments reduced the migration of Cd and As to rice grains. While biochar incorporation increased the concentration of Cd in the polished grains by 29.14 %. Statistical analyses indicated soil microbiome substantially contributed to the accumulation of Cd and As in the polished grains. Variables measured at the maturation and filling stage explained more changes of Cd and As in the maturation polished grains, respectively. Together, lime was the best soil conditioner. Future research might further increase food security by regulation on soil biotics at specific stage and eventually realize sustainable development of e-waste dismantling.