Módenes A N, de Abreu Pietrobelli J M T, Espinoza-Quiñones F R
Post graduate program of Chemical Engineering, Paraná West State University, rua da faculdade 645, Jd. Sta. Maria, 85903-000, Toledo PR, Brazil.
Water Sci Technol. 2009;60(2):293-300. doi: 10.2166/wst.2009.178.
In this work the removal potential on Cd(2+ ) by the non-living Egeria densa biomass has been studied. The influence of the metal solution pH, the plant drying and the metal solution temperature, and biosorbent grain size was previously studied in batch systems. The cadmium adsorption rate has increased when the pH was increasing, but at pH 5, the cadmium precipitation has begun to occur, avoiding such high pH values in other tests. The cadmium removal was around 70% at 30 degrees C biomass dried and solution temperatures, assuming as the best temperature conditions. No significant influence was observed in cadmium removal due to the grain size effect. The biosorption kinetic data were well fitted by a pseudo-second order model. The equilibrium time in experiments was around 45 min with a 70% Cd removal. The equilibrium data at pH 5 were described rather better by the Langmuir isotherm than the Freundlich one, with an adsorption rate and maximum metal content values of 0.40 L g(-1) and 1.28 meq g(-1), respectively, for Langmuir model. The kinetic parameter values are near to other biosorbents, indicating that the macrophytes E. densa could be used as biosorbent material in industrial effluent treatment system.
在这项工作中，研究了非活性伊乐藻生物质对镉离子（Cd(2+)）的去除潜力。之前在分批系统中研究了金属溶液pH值、植物干燥处理、金属溶液温度以及生物吸附剂粒度的影响。随着pH值升高，镉的吸附率增加，但在pH为5时，镉开始沉淀，因此在其他试验中避免使用如此高的pH值。在30℃的生物质干燥温度和溶液温度下，镉的去除率约为70%，此温度条件被视为最佳条件。未观察到粒度效应对镉去除有显著影响。生物吸附动力学数据很好地拟合了准二级模型。实验中的平衡时间约为45分钟，镉去除率为70%。对于Langmuir等温线模型，在pH为5时的平衡数据比Freundlich等温线拟合得更好，Langmuir模型的吸附速率和最大金属含量值分别为0.40 L g(-1)和1.28 meq g(-1)。动力学参数值与其他生物吸附剂相近，表明大型植物伊乐藻可作为工业废水处理系统中的生物吸附材料。
