两种典型湖南森林土壤SO_4^(2-)NO_3^-吸附及解吸的研究

Adsorption and Desorption of and in Two Hunan Forest Soils

采用现场采集土样及室内处理和分析方法,研究了2种典型湖南森林土壤对SO42-、NO3-的吸附及解吸规律。结果表明,红壤和黄红壤都具有相当强的SO42-和NO3-吸附能力,但其NO3-最大吸附量约为SO42-吸附量的39%～62%;表土SO42-解吸率远高于底土SO42-解吸率,且NO3-解吸率明显低于SO42-解吸率;土壤SO42-和NO3-的解吸率随着解吸液pH值的下降而下降;由于SO42-与NO3-的竞争,共同吸附试验中土壤对SO42-或NO3-的吸附量都小于单独吸附试验中的吸附量,共同解吸试验中解吸液明显增加了对SO42-的解吸率而降低了对NO3-的解吸率。

Adsorption and desorption of sulfate and nitrate in two Hunan forest soils were studied through field sampling and labo ratory analysis of soil. The results showed that the red soil and yellow- red soil had a quite strong ability to absorb and , and the maximum amount of adsorption was about 39% ～ 62% of that of adsorption. Desorption ratios of from the top soils were much greater than those from the bottom soils, and desorption rate was obviously lower than that of . With decreasing pH values of extraction solutions, desorption ratios of and decreased. Due to the competition of and in the co- adsorption experiment, the adsorption amount of or was less than that in the seprate adsorption experiments, while the extraction solutions increased desorption ratios of but decreased those of in the co- desorption process apparently.