College of Resource and Environmental Science, China Agricultural University Beijing, PR China; Department of Environmental Sciences and Engineering, Government College University Faisalabad, Pakistan.
College of Resource and Environmental Science, China Agricultural University Beijing, PR China.
Chemosphere. 2020 Mar;242:125152. doi: 10.1016/j.chemosphere.2019.125152. Epub 2019 Oct 21.
Cadmium (Cd) contamination of paddy soils has raised serious concerns for food safety and security. Remediation and management of Cd contaminated soil with biochar (BC) and modified biochar is a cost-effective method and has gained due attention in recent years. Goethite-modified biochar (GB) can combine the beneficial effects of BC and iron (Fe) for remediation of Cd contaminated soil. We probed the impact of different BC and GB amendments on Cd mobility and transfer in the soil-rice system. Both BC and GB effectively reduced Cd mobility and availability in the rhizosphere and improved the key growth attributes of rice. Although BC supply to rice plants enhanced their performance in contaminated soil but application of 1.5% GB to the soil resulted in prominent improvements in physiological and biochemical attributes of rice plants grown in Cd contaminated soil. Sequential extraction results depicted that BC and GB differentially enhanced the conversion of exchangeable Cd fractions to non-exchangeable Cd fractions thus restricted the Cd mobility and transfer in soil. Furthermore, supplementing the soil with 1.5% GB incremented the formation of iron plaque (Fe plaque) and boosted the Cd sequestration by Fe plaque. Increase in shoot and root biomass of rice plants after GB treatments positively correlates with incremented chlorophyll contents and gas exchange attributes. Additionally, the oxidative stress damage in rice plants was comparatively reduced under GB application. These findings demonstrate that amending the soil with 1.5% GB can be a potential remediation method to minimize Cd accumulation in paddy rice and thereby can protect human beings from Cd exposure.
镉（Cd）污染稻田引起了人们对食品安全和保障的严重关注。利用生物炭（BC）和改性生物炭修复和管理受 Cd 污染的土壤是一种具有成本效益的方法，近年来受到了应有的重视。针铁矿改性生物炭（GB）可以结合 BC 和铁（Fe）的有益作用，用于修复受 Cd 污染的土壤。我们研究了不同 BC 和 GB 改良剂对土壤-水稻系统中 Cd 迁移和转化的影响。BC 和 GB 都能有效地降低根际土壤中 Cd 的迁移性和有效性，并改善水稻的关键生长特性。虽然向受污染土壤中提供 BC 会增强水稻在污染土壤中的性能，但向土壤中添加 1.5%的 GB 会显著改善在 Cd 污染土壤中生长的水稻的生理生化特性。连续提取结果表明，BC 和 GB 可促进可交换态 Cd 向非交换态 Cd 的转化，从而限制了 Cd 在土壤中的迁移和转化。此外，向土壤中添加 1.5%的 GB 会增加铁斑（Fe 斑）的形成，并通过铁斑促进 Cd 的固定。GB 处理后水稻地上部和根部生物量的增加与叶绿素含量和气体交换特性的增加呈正相关。此外，在施加 GB 时，水稻植株的氧化应激损伤相对减少。这些发现表明，向土壤中添加 1.5%的 GB 可以是一种潜在的修复方法，以最大限度地减少水稻对 Cd 的积累，从而保护人类免受 Cd 暴露。
