Cu^（2＋）对3种农药在Ca－蒙脱石和δ－Al_2O_3上吸附的影响

ADSORPTION OF THREE PESTICIDES ON CAMONTMORILLONITE AND δ-Al_2O_3 IN PRESENCE OR ABSENCE OF COPPER

比较研究了３种农药在两种吸附体上的吸附以及Ｃｕ２＋其吸附的影响．杀虫脒在Ｃａ－蒙脱石上的吸附率很高且随ｐＨ值的升高而降低；在δ－Ａｌ２Ｏ３上的吸附率较低且随ｐＨ值的升高而升高．Ｃｕ２＋对其吸附无影响，毒莠定在Ｃａ－蒙脱石上无吸附，但可被δ－Ａｌ２Ｏ３吸附，吸附率随ｐＨ值的升高逐渐降低，不受Ｃｕ２＋的影响．当ｐＨ值小于５时，草甘磷在Ｃａ－蒙脱石上的吸附随ｐＨ值的升高而略有上升；当ｐＨ值大于５时，则随ｐＨ值的升高而下降，Ｃｕ２＋降低了草甘磷的吸附．当草甘磷与Ｃｕ２＋摩尔比为０．５和１．０时，草甘磷吸附率的降低程度高于摩尔比为２．０时的降低程度．

The adsorption of chlordimeform and picloram on Ca-montmorillonite and δ-Al2O3 as well as the adsorption of glyphosate on Ca-montmorillonite in the presence and absence of copper were studied.The adsorption rate of chlordimeform was much higher on Ca-montmorillonite than on δ-Al2O3, which decreased on Ca-montmorillonite whereas increased on δ-Al2O3 with increasing pH. No apparent effect of copper on the adsorption was found.Picloram was not adsorbed on Ca-montmorillonite with or without copper.The adsorption rate of picloram on δ-Al2O2 was decreased by copper.The adsorption rate of glyphosate on Camontmorillonite increased slightly when pH< 5 while decreased when pH>5 as pH rose.The glyphosate adsorption decreased in a greater extent when the molar ratio of glyphosate to copper was 1 or 0.5 than when the ratio was 2.