Bouzid J, Elouear Z, Ksibi M, Feki M, Montiel A
Laboratoire Eau Energie et Environnement, Ecole Nationale d'Ingénieurs de Sfax, BP W 3038 Sfax, Tunisia.
J Hazard Mater. 2008 Apr 1;152(2):838-45. doi: 10.1016/j.jhazmat.2007.07.092. Epub 2007 Aug 2.
In the present work, the abilities of sewage sludge and pomace ashes to remove copper (Cu(2+)) ions from aqueous solutions are compared. Batch adsorption experiments were performed in order to evaluate the removal efficiency of these materials. Effect of contact time, solution pH, ash concentration and temperature on the removal of Cu(2+) was investigated. The results of batch equilibrium studies showed that the solution pH was the key factor affecting the adsorption characteristics. In general, the amount of Cu removed increased as the solid concentration and pH increased, and then it remained constant over a wide pH region. The adsorption test of applying sewage sludge and pomace ashes into synthetic wastewater revealed that the adsorption data of these materials for copper ions were better fitted to the Langmuir isotherm since the correlation coefficients for the Langmuir isotherm were higher than that for the Freundlich isotherm. The estimated maximum capacities of copper adsorbed by sewage sludge and pomace ashes were 5.71 and 6.98 mg g(-1), respectively. Experimental results indicated that the adsorption was favorable at higher pH and higher temperature. Values of DeltaG degrees ranging from -4.64 to -5.13 kcal mol(-1) for sewage sludge ash and from -4.97 to -5.53 kcal mol(-1) for pomace ash suggest that the adsorption reaction is a physical process enhanced by the electrostatic effect. The values of DeltaH degrees and DeltaS degrees are, respectively, 4.27 kcal mol(-1) and 30.6 cal K(-1)mol(-1) for sewage sludge ash and 4.33 kcal mol(-1) and 31.3 cal K(-1)mol(-1) for pomace ash. The mechanisms of copper removal by these materials included adsorption and precipitation. The sewage sludge and pomace ashes are shown to be effective adsorbents for this metal.
在本研究中，比较了污水污泥和果渣灰从水溶液中去除铜（Cu(2+)）离子的能力。进行了批量吸附实验以评估这些材料的去除效率。研究了接触时间、溶液pH值、灰分浓度和温度对Cu(2+)去除的影响。批量平衡研究结果表明，溶液pH值是影响吸附特性的关键因素。一般来说，随着固体浓度和pH值的增加，去除的铜量增加，然后在较宽的pH范围内保持恒定。将污水污泥和果渣灰应用于合成废水的吸附试验表明，这些材料对铜离子的吸附数据更符合朗缪尔等温线，因为朗缪尔等温线的相关系数高于弗伦德利希等温线。污水污泥和果渣灰吸附铜的估计最大容量分别为5.71和6.98 mg g(-1)。实验结果表明，在较高的pH值和较高的温度下吸附效果良好。污水污泥灰的ΔG°值范围为-4.64至-5.13 kcal mol(-1)，果渣灰的ΔG°值范围为-4.97至-5.53 kcal mol(-1)，这表明吸附反应是一个受静电效应增强的物理过程。污水污泥灰的ΔH°和ΔS°值分别为4.27 kcal mol(-1)和30.6 cal K(-1)mol(-1)，果渣灰的ΔH°和ΔS°值分别为4.33 kcal mol(-1)和31.3 cal K(-1)mol(-1)。这些材料去除铜的机制包括吸附和沉淀。污水污泥和果渣灰被证明是这种金属的有效吸附剂。
