Chingombe P, Saha B, Wakeman R J
Advanced Separations Technologies Group, Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.
J Colloid Interface Sci. 2006 May 15;297(2):434-42. doi: 10.1016/j.jcis.2005.10.054. Epub 2005 Dec 9.
The performance of a conventional (F400) and a surface modified activated carbon (F400AN) has been investigated for the sorption of benazolin and 2,4-dichlorophenoxy acetic acid (2,4-D) from water. It was observed that the modified carbon, F400AN, which was obtained by annealing the conventional sample had a higher BET surface area (960 m2 g(-1) compared to 790 m2 g(-1)) and it had a higher proportion of micropores. This was attributed to the loss of oxygen containing functional groups during the thermal treatment. Zeta potential and pH titration measurements also showed that acidic functionality had been lost on the F400AN sample. The adsorption data were analysed and were fitted well using the Langmuir isotherm. The modified carbon marginally out-performed the conventional activated carbon for sorption of these two herbicides. Thermodynamic parameters (DeltaG0, DeltaH0, and DeltaS0) were determined and their values indicated that the sorption process was spontaneous and endothermic for both herbicides. A pseudo-second-order kinetic model was employed for analysing the kinetic data. It was concluded that the herbicide sorption process was controlled by a film diffusion mechanism.
研究了常规（F400）活性炭和表面改性活性炭（F400AN）从水中吸附苄草隆和2,4-二氯苯氧乙酸（2,4-D）的性能。观察到，通过对常规样品进行退火处理得到的改性碳F400AN具有更高的BET表面积（960 m2 g(-1)，而常规样品为790 m2 g(-1)），且其微孔比例更高。这归因于热处理过程中含氧化官能团的损失。zeta电位和pH滴定测量还表明，F400AN样品上的酸性官能团已丧失。对吸附数据进行了分析，并使用朗缪尔等温线进行了良好拟合。对于这两种除草剂的吸附，改性碳的性能略优于常规活性炭。测定了热力学参数（ΔG0、ΔH0和ΔS0），其值表明这两种除草剂的吸附过程都是自发的且吸热的。采用准二级动力学模型分析动力学数据。得出的结论是，除草剂的吸附过程受膜扩散机制控制。
