Applying modified biochar with nZVI/nFe3O4 to immobilize Pb in contaminated soil

• Published in: Environmental science and pollution research international Vol. 27; no. 19; pp. 24495 - 24506
• Main Authors: Li, Peirou, Yu, Jiang, Huangfu, Zhuoxi, Chang, Jiahua, Zhong, Chengwei, Ding, Ping
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2020; Springer Nature B.V
• Subjects: Acid rain; Acidic soils; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Charcoal; Curing; Curing agents; Earth and Environmental Science; Ecotoxicology; Efficiency; Environment; Environmental Chemistry; Environmental Health; Environmental science; Heavy metals; Immobilization; Industrial pollution; Industrial sites; Iron; Leaching; Lead; Rain; Research Article; Soil conditions; Soil contamination; Soil investigations; Soil pollution; Soil remediation; Soils; Waste Water Technology; Water Management; Water Pollution Control; Nano-zero-valent iron; Immobilize; Acid rain; Pb-contaminated soil; Modified biochar; Nano-ferroferric oxide
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-08458-0

Lead (Pb) pollution in soil has become one of the most serious environmental problems, and it is more urgent in areas where acid rain is prevalent. Curing agents to solidify heavy metals in soil are efficiently applied to remediate Pb-contaminated soil. In this study, we prepared biochar, biochar loaded with nano-zero-valent iron (BC-nZVI), and biochar loaded with nano-ferroferric oxide (BC-nFe 3 O 4 ), and investigated the Pb-immobilizing efficiency in contaminated soil in the condition of acid rain by them. The results showed that 8 g/kg is the best added dosage of curing agents for immobilizing Pb, which of the immobilizing efficiency of Pb were 19% (biochar), 42% (BC-nZVI), and 23% (BC-nFe 3 O 4 ), respectively. Besides, the curing agents had positive effects on immobilizing Pb under acid rain condition, which could significantly reduce the content of acid extractable Pb, especially BC-nZVI (1.5%). And the immobilization efficiency of modified biochar was better than biochar, especially BC-nZVI (66%). BC-nZVI showed a more ideal effect on decreasing the leaching amount of Pb in the condition of acid rain. The results highlighted that biochar-loaded nano-iron-based materials, especially BC-nZVI, was promising and environmentally friendly materials for remediating Pb-contaminated soils, which provided scientific reference and theoretical basis for the treatment of Pb-contaminated soils around industrial sites particularly in acid rain area.