Technical University of Crete, Department of Environmental Engineering, Laboratory of Toxic and Hazardous Waste Management, University Campus, P.C. 73100, Chania, Crete, Greece.
J Hazard Mater. 2010 Jun 15;178(1-3):136-43. doi: 10.1016/j.jhazmat.2010.01.053. Epub 2010 Jan 18.
The removal of BTEX (benzene, toluene, ethyl-benzene and xylenes) and MTBE (methyl tertiary butyl ether) from aqueous solution by raw (D(R)) and thermally modified diatomite at 550, 750 and 950 degrees C (D(550), D(750) and D(950) respectively) was studied. Physical characteristics of both raw and modified diatomite such as specific surface, pore volume distribution, porosity and pH(solution) were determined, indicating important structural changes in the modified diatomite, due to exposure to high temperatures. Both adsorption kinetic and isotherm experiments were carried out. The kinetics data proved a closer fit to the pseudo-second order model. Maximum values for the rate constant, k(2), were obtained for MTBE and benzene (48.9326 and 18.0996 g mg(-1)h(-1), respectively) in sample D(550). The isotherm data proved to fit the Freundlich model more closely, which produced values of the isotherm constant 1/n higher than one, indicating unfavorable adsorption. The highest adsorption capacity, calculated through the values of the isotherm constant k(F), was obtained for MTBE (48.42 mg kg(-1) (mg/L)(n)) in sample D(950).
从水溶液中去除 BTEX（苯、甲苯、乙苯和二甲苯）和 MTBE（甲基叔丁基醚），使用未经处理的（D(R)）和在 550、750 和 950°C 下热改性的硅藻土（分别为 D(550)、D(750)和 D(950)）。测定了原始和改性硅藻土的物理特性，如比表面积、孔径分布、孔隙率和 pH 值（溶液），表明改性硅藻土由于暴露于高温而发生了重要的结构变化。进行了吸附动力学和等温线实验。动力学数据证明更符合拟二级模型。在 D(550)样品中，对于 MTBE 和苯，速率常数 k(2)的最大值分别为 48.9326 和 18.0996 g mg(-1)h(-1)。等温线数据证明更符合 Freundlich 模型，其等温线常数 1/n 的值大于 1，表明吸附不利。通过等温线常数 k(F)的值计算出的最大吸附容量，在 D(950)样品中 MTBE 最高（48.42 mg kg(-1)（mg/L)(n)）。
