酸性硫酸盐土中铝的形态

采用连续分级提取方法 ,把酸性硫酸盐土中可提取的非晶体态铝区分为交换态铝 (ExAl)、吸附态无机羟基铝 (HyAl)、有机配合铝 (OrAl)、氧化铁结合铝 (DCBAl)、层间铝 (InAl)和非晶体态铝硅酸盐 (NcAl) ,其平均值分别为 1.79、2 .5 1、4.17、4.14、4.31和 18.6 6g·kg-1Al2 O3.实际酸性硫酸盐土中NcAl>OrAl >InAl >DCBAl>ExAl>HyAl,潜在酸性硫酸盐土NcAl >InAl >DCBAl >HyAl >OrAl >ExAl.可提取Al总量平均为 35 .5 7Al2 O3g·kg-1,占全Al 2 5 .0 4% .其显著特征是活性铝ExAl、HyAl和OrAl的含量较高 .每一种Al形态的结构组成与酸性硫酸盐土相应性质和生态特性密切相关 .酸化的ASS的强酸环境导致Al的过量游离 ,并转化为活度较大的活性Al,从而产生Al毒

Aluminum forms in Acid Sulfate Soils

With the method of sequential extraction,the extractable noncrystalline aluminum in Acid Sulfate Soils was fractionized into exchangeable Al (ExAl),absorbed inorganic hydroxy Al(HyAl),organic complexed Al(OrAl),Fe oxide bound Al (DCBAl),interlayered Al(InAl) and noncrystalline aluminosilicate(NcAl) with average of 1.79,2.51,4.17,4.14, 4.31 and 8.66gAl 2O 3.kg -1 ,respectively.In actual Acid Sulfate Soils, the amount of different forms Al followed the order of NcAl>OrAl>InAl>DCBAl>ExAl>HyAl, but in potential acid sulfate soils, NcAl>InAl>DCBAl> HyAl>OrAl>ExAl. The average of the total extractable noncrystalline Al was 35.57 g Al 2O 3.kg -1 ,which covered 25.04 % of the total amount of Al in Acid Sulfate Soils. The characteristic of extractable noncrystalline Al in Acid Sulfate Soils was the high proportion of active aluminum, such as ExAl,HyAl and OrAl. All forms of Al were closely related to the corresponding properties and ecological characteristics of Acid Sulfate Soils. The strong acid environment of actual Acid Sulfate Soils induced over released Al, which transformed to active Al and resulted in Al toxicity.