磁性纳米Fe_3O_4对毒死蜱的增效和催化降解研究

Enhanced Effect and Photocatalytic Degradation of Chlorpyrifos with Nano-magnetic Ferroso-ferric Oxide

应用溶剂热法制备了磁性纳米Fe3O4(NMFO),并用聚乙二醇-6000对其进行改性,使纳米Fe3O4表面由亲水性转变为亲脂性,从而实现与亲脂性毒死蜱的复合。纳米Fe3O4的加入使毒死蜱的生物活性明显提高。室内毒力试验结果表明:含0.2%纳米Fe3O4的Fe3O4/毒死蜱制剂的毒力在室内和紫外光照下分别是同浓度纯毒死蜱的3.84倍和4.17倍;其降解率也显著提高,纳米Fe3O4/毒死蜱制剂在太阳光照下放置10 d,其降解率可达93.2%,相同条件下纯毒死蜱的降解率是10.14%,而将添加或未添加纳米Fe3O4的毒死蜱于暗处放置相同的时间,其降解率分别为1.21%和0.23%。

Laboratory experiments were conducted, in which nano-magnetic ferroso-ferric oxide （NMFO）were prepared by the solve-thermal method and the products were modified using polyethylene glycol-6000 to change surface properties of NMFO from hydrophilic to hydrophobic, and then lipophilic, allowing TMFO to combine with chlorpyrifos that was of lipophilic characteristics. Hence, the bioactivity, i.e., virulence of chlorpyrifos was remarkably enhanced after being mixed with NMFO. In addition, indoor bioassay tests were carried out to compare the photocatalytic degradation rate of chlorpyrifos with and without NMFO addition, indicating that NMFO could greatly strengthen the degradation under sun-light irradiation for 10 days; however, the degradation would be negligible in dark either with or without NMFO added.