恒电荷土壤和可变电荷土壤动电性质的研究 Ⅱ.阴离子吸附和pH的影响  

STUDIES ON ELECTROKINETIC PROPERTIES OF CONSTANT CHARGE SOILS AND VARIABLE CHARGE SOILS II. EFFECT OF ANION ADSORVTION AND pH

作　　者：李成保[1] 季国亮[1] 

机构地区：[1]中国科学院南京土壤研究所,南京210008

出　　处：《土壤学报》2000年第1期62-68,共7页Acta Pedologica Sinica

基　　金：国家自然科学基金!49471041;49631010和49771046

摘　　要：本工作研究了阴离子吸附和ｐＨ对恒电荷土壤（黄棕壤和黑土）和可变电荷土壤（砖红壤）动电性质的影响。结果表明，砖红壤吸附不同阴离子后的ζ电位随ｐＨ升高由正电位移至负电位，在（电位－ｐＨ曲线上均有一个等电点（ＩＥＰ）；在 ｐＨ３．５～８之间，相同ｐＨ下，砖红壤的ζ电位随吸附阴离子的负移顺序是ＨＰＯ２－４＞Ｆ－＞ＳＯ２－４＞Ｃｌ－＞ＮＯ－３：作为恒电荷土壤的黄棕壤和黑土，在不同电解质溶液中的ζ电位均为负值，没有等电点；ζ电位－ｐＨ曲线的形状随土壤、溶液和ｐＨ而异。在ｐＨ５．５～９之间，黄棕壤和黑土吸附阴离子后ζ电位负移具有相同的顺序：ＳＯ２－４＞ＨＰＯ２－４≥Ｆ－＞Ｃｌ－＞ＮＯ－３。Summary In this work, effects of anion adsorption and pH on the electrokinetic properties of constant charge soils and variable charge soils were studied. Yellow Brown soil and Phaeozem were used as representatives of constant charge soils, and Latosol was used as representative of variable charge soils. The results showed that the zeta Potential of Latosol particles which had adsorbed different anions changed to negative from positive in sign with the increase in pH and an isoelectric point (IEP) occurred on all the zeta potential-PH curves. In the pH range of 3.5-8.0, the absolute value of change in seta potential of Latosol particles adsorbed different anions was of the order HPO2-4 > F- > SO2-4 > Cl- > NO3- The zeta potentials of yellow brown soil and Phaeozem particles referred as constant charge soil were always negative in sign and no IEP occurred on zeta potential-pH curves. The shape of zeta potential-PH curves varied with the soil type, the anion kind and the pH. In the pH range of 5.5- 9, the absolute value of change in zeta potential of yellow brown soil and Phaeozem which had adsorbed different anions was of the order SO2-4 > HPO2-4->F-> Cl- > NO-3

关 键 词：阴离子吸附 PH 动电电位 恒电荷 土壤 可变电荷 

分 类 号：S153.2[农业科学—土壤学]