【摘要】 人工模拟铜污染棕壤,通过添加不同裂解温度(350℃、500℃和650℃)和不同施用量(2%和4%)的花生秸秆生物炭,探究生物炭输入对土壤pH和铜形态(Tessier连续提取法)的影响,分析生物炭输入对棕壤铜生物有效性的影响机制。结果表明:随着制备温度的升高,生物炭产率、平均孔径减小,pH、灰分、阳离子交换量(CEC)和比表面积增大;施加生物炭提高了土壤pH,土壤pH与交换态铜含量成负相关,且随生物炭裂解温度和添加量的增加而升高;施炭量一定条件下,随着输入生物炭裂解温度的升高,土壤交换态铜、铁锰氧化物结合态铜含量显著减少(P<0.05),有机化合态铜含量显著增加(P<0.05),残渣态含量增多,其中650℃裂解温度生物炭处理对降低土壤铜有效性效果最好;在相同的裂解温度下,随着施炭量增加,土壤交换态、碳酸盐结合态和铁锰氧化物结合态铜含量减少,有机化合态铜和残渣态铜含量增多,其中以4%施炭量处理对降低土壤有效态铜的效果最优。研究结果表明,生物炭裂解温度和添加量是影响棕壤pH和铜生物有效性的因子,其中SP4-650处理最有利于降低棕壤中铜生物有效性。更多还原

【Abstract】 The different pyrolysis temperatures(350℃,500℃ and 650℃) and different amounts(2% and 4%) of biochars derived from peanut straw were input to Brown Earth simulated copper(Cu) pollution artificial and their effects were explored on five chemical Cu fractions extracted with Tessier sequential extraction method in soil.And the influence of biochar input on the Cu bioavailability was analyzed.Results showed that the yield and the average pore size of biochar reduced,in contract,its pH value,ash content,cation exchange capacity(CEC) and specific surface area increased with the increase in preparation temperature of biochar.Input of biochar increased soil pH values.There was a negative correlation between soil pH and exchangeable Cu content and the pH of soil were increased with pyrolysis temperatures and amount of biochar.Different pyrolysis temperatures of biochar addition have different effects on the bioavailability of Cu in soil.With the increase of pyrolysis temperatures,the contents of exchangeable Cu and Fe-Mn oxides-bound Cu decreased,the organic Cu increased significantly(P<0.05) and the residue Cu content slightly raised.Among them,the effect of 650 ℃ biochar had the best effect on decreasing the bioavailability of Cu in soil.In the same pyrolysis temperatures,the content of exchangeable Cu,carbonate-bound Cu and Fe-Mn increase of the oxides-bound Cu in soil were decreased,while the contents of organic Cu and residue Cu were increased with the amount of biochar.And there was a significant effect on reducing the Cu availability after the input of biochar at the rate of 4%.In conclusion,the treatment of SP4-650 was the most beneficial to decrease the Cu bioavailability in soil.更多还原