Effective Alleviation of Aluminum Phytotoxicity by Manure-Derived Biochar

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• 作者：Linbo Qian ; Baoliang Chen ; Dingfei Hu
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：March 19, 2013
• 年：2013
• 卷：47
• 期：6
• 页码：2737-2745
• 全文大小：451K
• 年卷期：v.47,no.6(March 19, 2013)
• ISSN：1520-5851

文摘

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 掳C (CM400) and the CM400 biochar washed with distilled鈥揹eionized 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 渭mol/L Al³⁺. 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 Al³⁺ evolved to less toxic Al(OH)₃ and Al(OH)₄^{鈥?/sup> 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 Al3+ 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.}