Weng Chih-Huang, Sharma Y C, Chu Sue-Hua
Department of Civil and Ecological Engineering, I-Shou University, Da-Hsu Township, Kaohsiung 84008, Taiwan.
J Hazard Mater. 2008 Jun 30;155(1-2):65-75. doi: 10.1016/j.jhazmat.2007.11.029. Epub 2007 Nov 17.
Adsorption of Cr(VI) onto spent activated clay (SAC), a waste produced from an edible oil refinery company, was investigated for its beneficial use in wastewater treatment. After pressure steam treatment, SAC was used as an adsorbent. The adsorption kinetic data were analyzed and fitted well in a pseudo-first-order equation and the rate of removal was found to speed up with decreasing pH and increasing temperature. Activation energy for the adsorption process was found to be 4.01-5.47 kcal/K mol. The Langmuir adsorption isotherm was used to fit the equilibrium data and the effect of pH, temperature and ionic strength were studied. The maximum adsorption capacities for Cr(VI) ranged from 0.743 to 1.422 mg/g for temperature between 4 and 40 degrees C under a condition of pH 2.0. The studies conducted show the process of Cr(VI) removal to be spontaneous at high temperature and endothermic in nature. From the waste utilization and environment point of view, the work carried out is important and useful. Results obtained can serve as baseline data for designing a treatment process using this low-cost adsorbent for the treatment of wastewater rich in Cr(VI).
研究了食用油精炼公司产生的废料废活性白土（SAC）对Cr(VI)的吸附作用，以探讨其在废水处理中的有益用途。经过压力蒸汽处理后，SAC用作吸附剂。对吸附动力学数据进行了分析，并很好地拟合了伪一级方程，发现去除速率随着pH值的降低和温度的升高而加快。吸附过程的活化能为4.01 - 5.47 kcal/K mol。用朗缪尔吸附等温线拟合平衡数据，并研究了pH值、温度和离子强度的影响。在pH 2.0的条件下，温度在4至40摄氏度之间时，Cr(VI)的最大吸附容量为0.743至1.422 mg/g。进行的研究表明，Cr(VI)的去除过程在高温下是自发的，并且本质上是吸热的。从废物利用和环境的角度来看，所开展的工作是重要且有用的。获得的结果可为设计使用这种低成本吸附剂处理富含Cr(VI)废水的处理工艺提供基线数据。
