灭草松在土壤中吸附的支配因素

通过振荡平衡法测定了灭草松在6种土壤中的吸附等温线,计算了灭草松在吸附过程中平均偏摩尔自由能的变化值.结果表明灭草松在其中5种土壤上的吸附等温线为直线,分配常数Kd 0.14～0.31mL·g^-;土壤吸附灭草松的强弱次序为:德清水稻土＞安吉水稻土(pH4.79)＞余杭水稻土＞临安红壤＞安吉水稻土(pH7.36)＞德清黄壤.土壤性质与分配常数的相关分析,发现支配灭草松在土壤上吸附的主要因素是pH值和土壤有机质含量.灭草松在土壤上的吸附主要是中性灭草松及其阴离子在土壤有机质中的分配,与有机质性质关系不大.

Factors Dominating the Sorption of Bentazon in Soils

Adsorption isotherms of bentazon in six selected soils were measured by using batch sorption method. Meanwhile the mean partial free energy change of chemical in sorption process was also calculated. The results showed the adsorption isotherms of herbicide in five soils all were linear, distribution coefficients ( K d) ranged from 0.14 mL·g^- to 0.31 mL·g^- , and the extent of soils adsorption the herbicide followed: Deqing paddy soil>Ji'an paddy soil(pH4.79)>Yuhang paddy soil>Lin'an red soil>Ji'an paddy soil(pH7.36)>Deqing loess. Investigation of K d vs. properties of soils indicated that both of the pH and content of soil organic matters were dominating factors that affected the adsorption of bentazon in soils, and adsorption of bentazon in soils equated the partitioning of neutral and anion form bentazon into soil organic, which was independent of the natural of soil organic matters.