湘南第四纪红壤吸附SO_4~(2-)的机理研究

本文研究了湖南第四纪红粘土及其发育的旱地和水田表层土壤对SO_4~2的吸附.结果表明这三种土壤吸附SO_4~2的顺序为;红粘土>旱地红壤>红壤性水稻土.而且随介质pH的升高,SO_4~2吸附量减少,吸附机理也发生改变:当介质pH6.5以后,解吸占优势.

RESEARCH ON THE MECHANISMS OF SULFATE ADSORPTION IN QUATERNARY RED SOILS IN SOUTHERN HUNAN

In this article, SO42- adsorption was studied by Quaternary Red Clay in southern Hunan Province and soils deriving from it. Results show that SO42- adsorption capacity in three red soils are in following order: Quaternary Red Clay>upland red soil>paddy soil. When pH values in the equilibrium solution increase, the adsorption capacity of sulphate capacity decreases, and the mechanism of SO42- adsorption changes as well. Most of the sulfate is to be absorbed through the displacement of corrdinated water molecules on the surface of the soil particles when pH values are less than ZPC of the soils; while among pH3. 5-6. 5, mainly through the displacement of hy-droxyle ions on the surface of the soil particles; and beyond pH6. 5, desorption of the absorbedis the prevalent procesess.