Department of Soil Chemistry, Plant Nutrition and Microbiology, Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, 7528809, Israel.
Discipline of Chemistry, University of Newcastle, Callaghan, NSW, 2308, Australia; School of Materials Science and Engineering, University of NSW, Kensington, NSW, 2052, Australia; ISEM and School of Physics, University of Wollongong, Wollongong, NSW, 2522, Australia.
Chemosphere. 2020 Mar;243:125332. doi: 10.1016/j.chemosphere.2019.125332. Epub 2019 Nov 11.
The potential of biochar to enhance phytorestoration of hexavalent chromium [Cr(VI)]-contaminated soils was investigated. Rooted cuttings of Ficus elastica Roxb. Ex Hornem were transplanted to soil treated with 0 or 25 mg kg Cr(VI), ‒Cr and +Cr designations respectively, and amended with cattle manure-derived biochar at 0, 10 and 50 g kg. Plants were grown for 180 d in a temperature-controlled greenhouse. In the ‒Cr treatment, biochar addition enhanced plant growth without affecting plant water status, leaf nutrient levels, photochemical efficiency, or hormone levels. In the absence of biochar, Ficus growth in the +Cr treatment was stunted, exhibiting decreased leaf and root relative water content and photochemical efficiency. Adding biochar to +Cr soil resulted in decreased Cr uptake into plant tissues and alleviated the toxic effects of soil Cr(VI) on plant growth and physiology, including decreased leaf lipid peroxidation. High-resolution electron microscopy and spectroscopy elucidated the biochar role in decreasing Cr mobility, bioavailability, and phytotoxicity. Spectroscopic evidence is suggestive that biochar mediated the reduction of Cr(VI) to Cr(III), which was subsequently incorporated into organomineral agglomerates formed at biochar surfaces. The dual function of biochar in improving F. elastica performance and detoxifying Cr(VI) demonstrates that biochar holds much potential for enhancing phytorestoration of Cr(VI)-contaminated soils.
研究了生物炭增强六价铬（Cr(VI)）污染土壤植物修复的潜力。将榕属植物的生根插条移栽到分别用 0 或 25mg/kg Cr(VI)（分别用 -Cr 和 +Cr 表示）处理的土壤中，并添加牛粪衍生的生物炭，添加量分别为 0、10 和 50g/kg。在温度可控的温室中，植物生长了 180 天。在 -Cr 处理中，生物炭的添加促进了植物的生长，而不影响植物的水分状况、叶片养分水平、光化学效率或激素水平。在没有生物炭的情况下，榕属植物在 +Cr 处理中的生长受到抑制，表现出叶片和根相对含水量以及光化学效率降低。向 +Cr 土壤中添加生物炭可减少植物组织对 Cr 的吸收，并缓解土壤 Cr(VI)对植物生长和生理的毒性作用，包括减少叶片脂质过氧化。高分辨率电子显微镜和光谱学阐明了生物炭在降低 Cr 迁移性、生物可利用性和植物毒性方面的作用。光谱学证据表明，生物炭介导了 Cr(VI)向 Cr(III)的还原，随后 Cr(III)被整合到生物炭表面形成的有机-矿物团聚体中。生物炭在提高榕属植物性能和解毒 Cr(VI)方面的双重功能表明，生物炭在增强 Cr(VI)污染土壤的植物修复方面具有很大的潜力。
