El-Shafey E I
Chemistry Department, Faculty of Science, Mansoura University, Mansoura 35516, Egypt.
J Environ Manage. 2007 Sep;84(4):620-7. doi: 10.1016/j.jenvman.2007.03.021. Epub 2007 May 9.
A carbonaceous sorbent was prepared from peanut shell via sulphuric acid treatment. Se(IV) removal from aqueous solution on the sorbent was studied varying time, pH, Se(IV) concentration, temperature and sorbent status (wet and dry). Se(IV) removal was faster using the wet sorbent than the dry sorbent following a pseudo-first-order model. Se(IV) removal increases at low pH values, and decreases as pH increases until pH 7. Sorption was found to fit the Langmuir equation and sorption capacity for the wet sorbent was higher than that for the dry one. Both sorbents showed an increased selenium sorption by rising the temperature. Redox processes between Se(IV) and the carbon sorbent are involved. Analysis by scanning electron microscope and X-ray powder diffraction for the sorbent after the reaction with acidified Se(IV) confirmed the availability of elemental selenium as particles on the sorbent surface as a result of Se(IV) reduction. Physicochemical tests showed an increase in sorbent acidity, cation exchange capacity (CEC) and surface functionality after the reaction with acidified Se(IV), indicating the oxidation processes occurring on the sorbent surface. Due to its reduction properties, the sorbent seems efficient for Se(IV) removal from aqueous solution.
通过硫酸处理从花生壳制备了一种碳质吸附剂。研究了在不同时间、pH值、硒（IV）浓度、温度和吸附剂状态（湿态和干态）下，该吸附剂对水溶液中硒（IV）的去除情况。遵循准一级模型，湿吸附剂对硒（IV）的去除速度比干吸附剂快。在低pH值下，硒（IV）的去除率增加，随着pH值升高至7，去除率降低。吸附符合朗缪尔方程，湿吸附剂的吸附容量高于干吸附剂。两种吸附剂都随着温度升高而增加对硒的吸附。硒（IV）与碳吸附剂之间存在氧化还原过程。对与酸化硒（IV）反应后的吸附剂进行扫描电子显微镜和X射线粉末衍射分析，证实由于硒（IV）还原，吸附剂表面有元素硒颗粒存在。物理化学测试表明，与酸化硒（IV）反应后，吸附剂的酸度、阳离子交换容量（CEC）和表面官能度增加，表明吸附剂表面发生了氧化过程。由于其还原特性，该吸附剂似乎对从水溶液中去除硒（IV）有效。
