Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
Environ Sci Technol. 2013 Mar 19;47(6):2737-45. doi: 10.1021/es3047872. Epub 2013 Feb 26.
The alleviation of aluminum phytotoxicity to wheat plants in a hydroponic system through the amendment of biochar is investigated to explore the possibility of applying biochar in acidic soil amelioration. Biochar derived from cattle manure pyrolyzed at 400 °C (CM400) and the CM400 biochar washed with distilled-deionized water to remove alkalinity (WCM400) were prepared to determine the roles of the liming effect and adsorption during the alleviation of Al toxicity. Upon addition of 0.02% (W/V) CM400 to the exposure solution, the inhibition of plant growth by Al was significantly reduced while the toxic threshold was extended from 3 to 95 μmol/L Al(3+). Due to the biochar liming effect, the aluminum species were converted to Al(OH)(2+) and Al(OH)2(+) monomers, which were strongly adsorbed by biochar; furthermore, the highly toxic Al(3+) evolved to less toxic Al(OH)3 and Al(OH)4(-) species. Adsorption of Al by the biochar is dominated by surface complexation of the carboxyl groups with Al(OH)(2+)/Al(OH)2(+) rather than through electrostatic attraction of Al(3+) with negatively charged sites. Compared to the liming effect, the adsorption by biochar exhibited a sustainable effect on the alleviation of Al toxicity. Therefore, the biochar amendment appears to be a novel approach for aluminum detoxification in acidic soils.
在水培系统中，通过生物炭的改良来缓解铝对小麦植物的植物毒性，以探索在酸性土壤改良中应用生物炭的可能性。制备了来源于 400°C 热解牛粪便的生物炭（CM400）和用去离子水洗涤以去除碱性的 CM400 生物炭（WCM400），以确定在缓解铝毒性过程中石灰化作用和吸附的作用。在向暴露溶液中添加 0.02%（W/V）CM400 的情况下，铝对植物生长的抑制作用显著降低，而毒性阈值从 3 到 95 μmol/L Al(3+)延伸。由于生物炭的石灰化作用，铝的形态被转化为 Al(OH)(2+)和 Al(OH)2(+)单体，这些单体被生物炭强烈吸附；此外，高毒性的 Al(3+)演变成毒性较小的 Al(OH)3 和 Al(OH)4(-)形态。生物炭对 Al 的吸附主要是通过羧基与 Al(OH)(2+)/Al(OH)2(+)的表面络合，而不是通过 Al(3+)与带负电荷的位点之间的静电吸引。与石灰化作用相比，生物炭的吸附对缓解铝毒性具有可持续的效果。因此，生物炭的改良似乎是酸性土壤中铝解毒的一种新方法。
