Preparation of novel activated carbons from H2SO4-pretreated corncob hulls with KOH activation for quick adsorption of dye and 4-chlorophenol

Corncob hull was immersed in 25 wt% H(2)SO(4) and was carbonized in an oven at 290 °C for 2h to obtain the char. The char was then activated for 1h at 780 °C by KOH at weight ratio of KOH/char of 2.5, 3.0, and 3.5. SEM photos of the carbons revealed that the cell wall of corncob hull was etched into thin film structure. It was shown that the adsorption isotherms of methylene blue and 4-chlorophenol on the carbons were well fitted by the Langmuir equation. Moreover, the adsorption kinetics could be satisfactorily described by the Elovich equation. The normalized standard deviations are less than 2.8%. The high fraction of adsorption amount adsorbed within 1 min to that at saturation demonstrated the advantage of the prepared activated carbons. The fraction of adsorption amount within 1 min to that at saturation (q(1)/q(mon)) for the adsorption of 4-CP is high up to 0.807. Such quick adsorption behavior was mainly attributed to the presence of the thin film structure of carbons.     

基于响应面法的改性玉米芯吸附水中Zn~(2+)的工艺条件优化及机理研究

运用玉米芯作为生物吸附剂去除水溶液中Zn~(2+)。以单因素控制变量法考察了玉米芯用量、吸附时间、改性盐浓度和摇床转速对吸附性能的影响,并运用响应面法对吸附条件进行优化,通过吸附等温线、吸附动力学和热力学研究来探讨吸附机理。结果表明,当Zn~(2+)初始浓度为50 mg/L、改性盐浓度为0.26%、玉米芯用量为20 g/L、转速为203 r/min,于30℃的恒温振荡器中振荡吸附反应35 min后,吸附率可达80.40%。玉米芯对水溶液中Zn~(2+)的吸附是一个自发的吸附过程,其吸附行为符合二级反应速率方程和Langmuir吸附等温式,具有一定的应用前景。     

玉米芯粉处理含汞废水的研究

通过模拟试验探讨了经活化后的玉米芯粉吸附汞的效果及其主要技术参数，结果表明，玉米芯粉对汞的吸附平衡时间为１００ｍｉｎ，最大吸附量为０．９８５ｍｇ／ｇ，工作吸附量（穿透点）为０．４００ｍｇ／ｇ，该吸附剂容易洗脱与再生，且使用寿命长，最佳洗脱液为０．１％的稀硝酸溶液，吸附剂使用２０次后，效果仍较好，二级吸附对泵的去除率高达９９．７５％，出水浓度为０．０２５ｍｇ／Ｌ，可以使含Ｈｇ＾２＋１０．００ｍｇ／Ｌ