摘要
供试土样为中国的棕壤、红壤和赤红壤及巴基斯坦的gujranwalaseries和kotliseries.与H-粘粒比,H-粘粒复合体有较多的净负电荷和较少的正电荷。在红壤和赤红壤中,H-粘粒复合体的表面积比H-粘粒大,但在棕壤,gujranwalaseries和kotliseries中则相反。在pH近7.0时,因有机质而使负电荷百分数增加的次序为赤红壤>红壤>gujranwalaseries>kotliseries>棕壤。当pH<7时有机质可以提高赤红壤、红壤和kotliseries对锌的吸附,在各种锌浓度下,有机质均能提高棕壤和gujranwalaseries对锌的吸附。与Langmuir和Temkin方程比较,Freundlich方程最适合描述H-粘粒复合体对锌的吸附行为,但Langmuir方程最适合于自然粘粒复合体。
Three soils fron China ie. fragiaqualf(brown soil),udult(red soil)and oxisol(laterit-ic red earth)and two from Pakistan i.e. hoplustalf (gujranwala series)and chromustert(kotli se-ries)were studied.Net negative charges of H-clay complexes were found more and positive charges less than those of H-clays. H-clay complexes of udul and oxisol had larger surface area than H-clay,while reverse was true in fragiaqualf,hoplustalf an chromustert.The perecentage of increase in negative charge due to organic matter near pH 7.0 followed the order of oxisol > udult>ho-plustalf>chromustert>fragiaqualf Organic matter increased the adsorption of zinc by oxisol,udult and chromustert at pH<7.0,and by fragiaqualf and hoplustalf at all Zn concentrations. Freundlich equation was found to be best fit in H-clays and H-clay complexes as compared to Langmuir and Temkin equations. Langmuir equation was found to be the best fit in natural clay complexes.
关键词
土壤
表面电荷
锌
吸附
有机质
soil
surface charge
zinc adsorption
H-clay complexes