Department of Property Protection and Security, Osmancık Ömer Derindere Vocational School, Hitit University, 19500, Osmancık, Turkey.
Department of Chemistry, Faculty of Science, Hacettepe University, 06800, Ankara, Turkey.
Environ Sci Pollut Res Int. 2019 Nov;26(32):33631-33641. doi: 10.1007/s11356-019-06423-0. Epub 2019 Oct 6.
Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4'-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption-desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory-Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract.
农药对环境和人类健康危害极大，其在农业中的使用量不断增加。尽管 1,1,1-三氯-2,2-双（4-氯苯基）乙烷 4,4'-DDT 在发达国家已被禁用，但由于其在环境中的积累，它仍然是最危险的化学物质之一。已知 DDT 的毒性会影响一些生物化学酶系统。本研究的主要动机是开发一种有效的吸附剂，从水相中去除 DDT，DDT 被选为一种模型疏水性农药。为此，对天然硅藻土颗粒进行了磁性修饰，并附着了一种疏水性配体，以增强其吸附和物理化学特性。在最佳条件下，具有疏水性和磁性的硅藻土颗粒的吸附容量高达 120mg/g，硅藻土颗粒的修饰降低了平均孔径，而表面积和总孔体积增加了（约 15 倍）。经过五次连续的吸附-解吸循环，没有观察到吸附能力的显著下降。应用于数据的吸附等温线（朗缪尔、弗罗因德利希和弗洛里-欣格尔）表明，吸附过程是通过单层吸附以熵驱动的方式发生的。动力学数据还表明，吸附过程迅速，不存在任何扩散限制。
