苯磺隆在河南主要土壤类型中的吸附特性

应用平衡振荡法进行了苯磺隆在黄棕壤、砂姜黑土、褐土、潮土等河南省4种典型土壤中的吸附动力学试验,测定了各自的吸附常数,以期明确苯磺隆在河南省主要土壤类型中的吸附特性,为其合理使用提供指导。结果表明,4种供试土壤中苯磺隆的吸附动力学曲线均呈现"前快后慢"的趋势,黄棕壤中饱和吸附量(32%)、吸附常数(2.414 5)均最大,潮土中(21%、0.543 2)均最小。吸附常数与土壤物理化学性质相关性顺序为:有机质含量黏粒含量p H值阳离子交换量。苯磺隆在4种供试土壤中的吸附均符合Freundich模型,吸附自由能的变化均小于40 k J/mol,以物理吸附为主。

Adsorption Characteristics of Tribenuron-methyl in Main Soils of Henan Province

To investigate the adsorption characteristics of tribenuron-methyl in four typical soils of Henan province(yellow brown soil,cinnamon soil,Shajiang black soil,tidal soil),the dynamics experiment was carried and the adsorption constant was determined using the batch equilibration technique. The results showed that the trends of adsorption dynamic in the four typical soils were fast at start and slow in the end. The maximum saturated adsorption capacity and adsorption constant were 32% and 2. 414 5 in yellow brown soil,the minimum in tidal soil were 21% and 0. 543 2. The relativity of adsorption constant to physical and chemical properties of the soil was as follows:organic content> clay content>pH value>cation exchange capacity. The adsorption of tribenuron-methyl in the four typical soils all fitted Freundich equation well,and the changes of free energy for adsorption were less than 40 kJ/mol,suggesting that the adsorption was physical reaction.