Arias Arias Fabian E, Beneduci Amerigo, Chidichimo Francesco, Furia Emilia, Straface Salvatore
Department of Environmental and Chemical Engineering, University of Calabria, Via P. Bucci, Cubo 41B, 87036 Arcavacata di Rende, CS, Italy.
Department of Chemistry and Chemical Technologies, University of Calabria, Via P. Bucci, Cubo 15D, 87036 Arcavacata di Rende, CS, Italy; SIRiA S.r.l. - Servizi Integrati e Ricerche per l'Ambiente, Spin-off of the University of Calabria, Italy.
Chemosphere. 2017 Aug;180:11-23. doi: 10.1016/j.chemosphere.2017.03.137. Epub 2017 Apr 2.
WHO has declared mercury as one of the most dangerous pollutants for human health. Unfortunately, several cases of rivers and aquifers contaminated by mercury inevitably poses the problem on how to remediate them. Considerable efforts are being addressed to develop cost-effective methodologies, among which the use of low-cost adsorbing materials. In this paper, the adsorption performances of an alternative lignocellulosic material derived from the Spanish broom plant, are presented. This plant is widely diffused in the world and its usage for Hg(II) removal from water in real working conditions requires only minimal pretreatment steps. A thoroughly investigation on the kinetics and thermodynamics of Hg(II) adsorption on Spanish broom is presented, by using Hg(II) polluted aqueous solutions specifically prepared in order to simulate typical groundwater conditions. Several batch experiments, under static conditions, were carried out in order to evaluate the effect of pH, contact time, adsorbent dosage, initial concentration, temperature. A maximum adsorption capacity of 20 mg L can be obtained at pH 5, following a pseudo second order kinetics. Moreover, adsorption experiments in dynamic conditions were carried out using Spanish broom filters. Interestingly, a systematic, unconventional double S-shape breakthrough curve was observed under different experimental conditions, revealing the occurrence of two adsorption processes with different time scales. This behavior has been fitted by a bimodal Thomas model which, unlike the single Thomas fitting, gives satisfactory results with the introduction of a new parameter related to the fraction of surface active sites involved in the adsorption processes.
世界卫生组织已宣布汞是对人类健康危害最大的污染物之一。不幸的是，几起河流和含水层被汞污染的案例不可避免地带来了如何对其进行修复的问题。目前正在投入大量努力来开发具有成本效益的方法，其中包括使用低成本吸附材料。本文介绍了一种源自西班牙金雀花植物的替代性木质纤维素材料的吸附性能。这种植物在全球广泛分布，在实际工作条件下用于从水中去除汞（II）仅需极少的预处理步骤。本文通过使用专门配制以模拟典型地下水条件的汞（II）污染水溶液，对西班牙金雀花对汞（II）吸附的动力学和热力学进行了全面研究。在静态条件下进行了多项批量实验，以评估pH值、接触时间、吸附剂用量、初始浓度、温度的影响。在pH值为5时，遵循准二级动力学，可获得最大吸附容量为20毫克/升。此外，使用西班牙金雀花过滤器进行了动态条件下的吸附实验。有趣的是，在不同实验条件下观察到了系统的、非常规的双S形穿透曲线，揭示了存在两个具有不同时间尺度的吸附过程。这种行为已通过双峰托马斯模型进行拟合，与单峰托马斯拟合不同的是，通过引入一个与吸附过程中涉及的表面活性位点分数相关的新参数，该模型给出了令人满意的结果。
