复合改性粘土对除草剂2,4-D的控制释放作用研究

采用无机/有机复合改性粘土作制剂载体,探讨了其对阴离子型除草剂2,4-D的控制释放作用,目的在于延长2,4-D的持效期,同时减轻其污染。利用无机和有机改性的结合优势,复合改性粘土具有更强的吸附性能,能够显著延缓2,4-D在水中和土壤中的释放。分析其水中释放动力学数据得出,2,4-D释放50%所需时间(t50)长达73.8 h,远大于有机改性粘土作载体时的1 h。土壤层释放实验表明,当2,4-D载药量在20~80 mg/g之间时,复合改性粘土均能保持良好的控制释放效果。

Study on the controlled release of herbicide 2,4-D with complexly modified clay

Clay complexly modified with inorganic and organic cations was used as the carrier of anionic herbicide 2,4-D, and its performance on controlling the herbicide’ s release was investigated. The aim of this research was to prolong the activity of 2,4-D, and reduce its pollution. The modified clay had much higher adsorbability, and could obviously slow the release of 2,4-D in both water and soil. The results of release kinetics in water indicated the time taken for 50% 2,4-D to be released was as long as 73.8 h, and much longer than that of organically modified clay (1 h) being used as the carrier. According to the release experiments in soil layer, the complexly modified clay has very good performance on controlling 2,4-D release when the loading amount ranged between 20~80 mg/g.