不同土壤对阿散酸和洛克沙胂添加剂的吸附研究

Study on Absorption of p-Arsanilic Acid and Roxarsone by Different Soils in China

采用平衡振荡法,研究了不同利用类型的北方土和南方土对阿散酸和洛克沙胂2种有机胂添加剂的吸附行为.结果表明:有机质和总铁含量高的偏酸性南方土对2种有机胂的吸附强度远远大于有机质和总铁含量低的偏碱性北方土;北方土添加腐殖质后对阿散酸和洛克沙胂吸附量分别增加了3倍和10倍左右,南方土去除有机质后吸附量显著下降;南方树木园土和农场土对洛克沙胂和阿散酸的吸附更符合Langmuir吸附等温线,树木园土对阿散酸和洛克沙胂的饱和吸附量分别为1 111和1 250 mg.kg-1,农场土对阿散酸和洛克沙胂的饱和吸附量分别为66和250 mg.kg-1,初始质量浓度对洛克沙胂的吸附量影响更大.

The paper investigated the absorption of roxarsone(4-hydroxy-3-nitrophenylarsonic acid)and p-arsanilic acid(4-aminophenylarsonic acid)by southern and northern soils in China.The results showed that southern acidic soils with high organic matter and Fe content could absorb far more the two phenylarsonic acids than that of northern soils.Humic acid added into the northern soils could increase the absorption capacity as 3 times for p-arsanilic acid and 10 times for roxarsone,and southern soil decomposed organic matter decreased significantly its absorption capacity.Adsorption isotherms of two phenylarsonic acids by southern forest soil and farm soil fitted the Langmuir equation better,the statured adsorption capacity for roxarsone and p-arsanilic acid by southern forest soil were 1 111 and 1 250 mg·kg-1,respectively,those by southern farm soil were 66 and 250 mg·kg-1.Initial concentration had more effects on the absorption capacity of roxarsone.