Biochar Based on <i>Boehmeria nivea</i> from Arsenic--Contaminated Soil and the Effect on Soil

The utilization of remediating plants is an important factor that restricts phytoremediation.Ramie has good adsorption capacity for various heavy metals and is widely used in plant remediation.To achieve the multi-purpose development of heavy metal-contaminated ramie, research has been conducted on the preparation of biochar for using it as a raw material, and the feasibility of returning the prepared biochar to the soil has been explored.The results indicate that 300 ℃ is the appropriate pyrolysis temperature for preparing ramie biochar.Under these conditions, the biochar yield is 42.90 ± 2.29%, significantly higher than other pyrolysis temperatures, and the arsenic concentration is also lower.Removing arsenic from ramie biochar is crucial for biochar to return to the soil, and 85.62 ± 1.36% of arsenic can be removed through three rounds of 300 mM sodium hydroxide extraction.Adding modified biochar to heavy metalcontaminated soil can increase soil pH and organic matter content but does not significantly increase soil arsenic content.However, adding modified biochar did not significantly alter soil microbial community structure.A feasible plan for preparing reusable biochar using contaminated ramie was proposed in this study.The research results can directly serve the remediation of soil arsenic pollution using ramie and have reference significance for other plants to carry out heavy metal remediation.