Removal of Pesticides from Aqueous Solutions by Adsorption on Zeolites as Solid Adsorbents
Removal of Pesticides from Aqueous Solutions by Adsorption on Zeolites as Solid Adsorbents
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DOI：
10.1260/0263-6174.33.5.457
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发表时间：
2015-05-01
影响因子：
2.9
通讯作者：
Spanoghe, P.
中科院分区：
文献类型：
--
作者：
De Smedt, C.;Ferrer, F.;Spanoghe, P.
为防止农药污染地下水和地表水，应采取适当措施，在排放前对受污染的水进行处理。沸石是一种很有前途的农药吸附材料。本文研究了不同类型沸石对水中移动的农药的去除。通过实验研究了苯达松、二氯吡啶酸、吡虫啉、异丙隆和精甲霜灵在沸石上的吸附机理，并确定了最有效的吸附剂。更多的非移动的农药（吡虫啉，异丙隆和甲霜灵-m）往往与沸石，而更多的移动的农药（苯达松和二氯吡啶酸）分配在水中。从吸附率来看，沸石中的沸石对农药的吸附效果最好，而沸石中的沸石对农药的吸附效果最差。采用两种不同的动力学模型，即伪一级和伪二级模型，对动力学数据进行拟合。实验数据可以用准二级动力学模型来描述。吸附速率也与农药的迁移率一致。根据国际纯粹与应用化学联合会（International Union of Pure and Applied Chemistry），根据观察到的类型确定吸附等温线并进行建模。在这种情况下，最常观察到III型等温线。Freundlich模型，它描述了这种类型的等温线，给出了一个很好的适合的农药的吸附。不同的假设，可以描述这些III型等温线的含义，本文进行了讨论。这些假设是基于吸附物的颗粒尺寸、水在沸石上的吸附和晶体结构的改变。
To prevent the contamination of groundwater and surface water by pesticides, appropriate measures should be taken to treat the contaminated water before discharge. Zeolites seem to be a promising material to adsorb pesticides. This paper deals with the removal of mobile pesticides from water on different types of zeolites. Experiments were performed to understand the adsorption mechanisms of bentazon, clopyralid, imidacloprid, isoproturon and metalaxyl-m on zeolites and to determine the most efficient adsorbent for the purification of water contaminated by these pesticides. More immobile pesticides (imidacloprid, isoproturon and metalaxyl-m) tended to associate with the zeolites, whereas more mobile pesticides (bentazon and clopyralid) partitioned in water. According to the adsorption percentage, zeolite of the types BEA and FAU showed the best results for adsorbing the pesticides. Two different kinetic models, namely, pseudo-first-order and pseudo-second-order models, were used to fit the kinetics data. The experimental data were best described by the pseudo-second-order model. The rate of adsorption was also in line with the mobility of the pesticides. The adsorption isotherms were determined and modelled based on the observed types according to International Union of Pure and Applied Chemistry. The type III isotherm was most frequently observed in this case. The Freundlich model, which describes this type of isotherm, gave a good fit for the adsorption of the pesticides. Different assumptions, that could describe the meaning of these type III isotherms, are discussed in this paper. These assumptions are based on the particle size of the adsorbates, the water adsorption on the zeolites and the modifications of the crystal structures.