活化黏土对羧甲基壳聚糖控制吡虫啉释放的强化作用

Improvement by Activated Clay on the Controlled Release of Imidacloprid with Carboxymethyl Chitosan

[目的]以活化黏土为吸附剂,与羧甲基壳聚糖复合制备颗粒状控制释放制剂,以延缓吡虫啉释放、提高药效并控制其污染。[方法]分别采用水中释放实验、土壤表层淋出实验,考察颗粒制剂控制吡虫啉释放及抑制其淋溶的效果。[结果]颗粒制剂中吡虫啉在水中的半数释放时间(t50)延长至25.5 h,释放过程受费克扩散控制,9次淋洗后吡虫啉的累计淋出率仅为28.6%。[结论]活化黏土可以进一步延缓吡虫啉的释放,显著减少其对地下水的污染。

[Aims] Activated clay, as the sorbent, was used in combination with carboxymethyl chitosan to prepare the granular controlled release formulations, so as to extend the release of imidacloprid, enhance the efficacy and control its pollution. [Methods] The release experiments in water and leaching experiments through a thin soil layer were carried out to investigate the performance of the granular formulations on controlling the release and inhibiting the leaching of imidaeloprid. [Results] The time taken for 50% imidacloprid to be released （ts0） in water from the granular CRF was prolonged to 25.5 h, and the release was controlled by Fickian diffusion. After irrigation of 9 times, the cumulative ratio of imidacloprid leached accounted for only 28.6%. [Conclusions] The activated clay can further delay the release of imidacloprid, and reduce its pollution to groundwater.