MWNTs及MWNTs／TiO2对水中氧乐果的吸附特性

Adsorption Characteristics of Omethoate in Water Using MWNTs and MWNTs/TiO_2

通过平衡试验分析了多壁碳纳米管(MWNTs)及MWNTs/TiO_2复合材料对氧乐果的吸附行为,探讨了两种材料的吸附热力学与动力学特性。结果表明,p H值对两种材料吸附性能的影响不大,在相同条件下,MWNTs和MWNTs/TiO_2对水中氧乐果的吸附量随初始浓度的增加而增大,对100 mg/L氧乐果溶液的最大吸附量分别为74.9和5.4 mg/g。两种材料的吸附过程均符合假二级动力学模型,且MWNTs/TiO_2对氧乐果的吸附速率为0.012 7 g/(mg·min),约为MWNTs的10倍,说明MWNTs/TiO_2具备更强的吸附能力。两种材料的吸附等温线均可用Freundlich等温吸附模型描述。

The adsorption characteristics of multi-walled carbon nanotubes （MWNTs） and MWNTs/TiO2 on omethoate were comparatively tested in batch experiments. The results showed that the pH value had limited impact on the adsorption kinetics of either material. Under the same test conditions, the adsorption capacity on omethoate of MWNTs and MWNTs/TiO2 increased with the increase of initial concentrations. The maximum adsorption capacity on 100 mg/L omethoate was 74.9 mg/g and 5.4 mg/ g, respectively. The adsorption kinetic of the two adsorbents was both confirmed to follow the pseudo-second-order equation model. In addition, the adsorption rate of MWNTs/TiO2 was 0.012 7 g/（ mg ~ rain）, which was around 10 times of that of MWNTs. The results indicated that MWNTs/TiO2 had a stronger adsorption capability on omethoate. The adsorption isotherm of both adsorbents on omethoate was well described by Freundlich adsorption isotherm.