Facultad de Química, Universidad Nacional Autónoma de México, Cd. Universitaria, 04510 México, DF, Mexico.
J Hazard Mater. 2010 Mar 15;175(1-3):216-23. doi: 10.1016/j.jhazmat.2009.09.151. Epub 2009 Oct 20.
The adsorption of barium by Ca-exchanged clinoptilolite and montmorillonite is presented. The kinetics of adsorption of Ba(2+) were evaluated contacting 1g portion of each adsorber with 100mL 0.1N BaCl(2) for 200 h. Adsorption by Ca-clinoptilolite is defined by second-order kinetics of rate constant K(v) 8.232 x 10(-2) g mg(-1)h(-1) and maximum removal of 71.885 mg g(-1). It is a two-stage process initiated by a rapid uptake of Ba(2+) followed by more moderate kinetics. The adsorption isotherms were determined contacting 0.2g of each adsorber with 10 mL 0.1-0.005N BaCl(2)+CaCl(2) solution, Ba(2+)/Ca(2+) ratio 1, for periods of 7 days for the tuff and 2 days for the clay. The equilibrium adsorption is described by the Langmuir model, of equilibrium constant K 0.0151 L mg(-1) and maximum adsorption of 15.29 mg g(-1). The adsorption of Ba(2+) by Ca-exchanged montmorillonite also follows a second-order reaction of rate constant K(v) 3.179 x 10(-2) g mg(-1)h(-1), and calculated separation of 36.74 mg g(-1); the Langmuir isotherm is defined by the constant K 0.034 L mg(-1) and maximum adsorption of 15.29 mg g(-1). X-ray diffraction shows that the exchange of Ba(2+) modifies the d(001) of Ca-montmorillonite from 15.4 to 12.4A.
钙交换沸石和蒙脱石对钡的吸附。通过接触 1g 每种吸附剂与 100ml 0.1N BaCl(2)，在 200 小时内评价 Ba(2+)吸附的动力学。Ca-沸石的吸附由速率常数 K(v) 8.232 x 10(-2) g mg(-1)h(-1)和最大去除率 71.885 mg g(-1)的二级动力学定义。这是一个两阶段过程，由 Ba(2+)的快速吸收引发，随后动力学更为温和。通过接触 0.2g 每种吸附剂与 10ml 0.1-0.005N BaCl(2)+CaCl(2)溶液，Ba(2+)/Ca(2+)比值为 1，接触 7 天（凝灰岩）和 2 天（粘土）确定吸附等温线。平衡吸附由 Langmuir 模型描述，平衡常数 K 为 0.0151 L mg(-1)，最大吸附量为 15.29 mg g(-1)。Ca 交换蒙脱石对 Ba(2+)的吸附也遵循速率常数 K(v) 3.179 x 10(-2) g mg(-1)h(-1)的二级反应，计算分离度为 36.74 mg g(-1)；Langmuir 等温线由常数 K 0.034 L mg(-1)和最大吸附量 15.29 mg g(-1)定义。X 射线衍射表明，Ba(2+)的交换将 Ca-蒙脱石的 d(001)从 15.4 变为 12.4A。
