Tiruta-Barna Ligia, Fantozzi-Merle Catherine, de Brauer Christine, Barna Radu
Laboratory of Process and Environmental Engineering, National Institute of Applied Sciences of Toulouse, 135 av. de Rangueil, F-31077 Toulouse Cedex, France.
J Hazard Mater. 2006 Nov 16;138(2):331-42. doi: 10.1016/j.jhazmat.2006.05.119. Epub 2006 Jul 16.
The aim of this paper is the investigation of the leaching behaviour of different porous materials containing organic pollutants (PAH: naphthalene and phenanthrene). The assessment methodology of long term leaching behaviour of inorganic materials was extended to cement solidified organic pollutants. Based on a scenario-approach considering environmental factors, matrix and pollutants specificities, the applied methodology is composed of adapted equilibrium and dynamic leaching tests. The contributions of different physical and chemical mechanisms were identified and the leaching behaviour was modelled. The physical parameters of the analysed reference and polluted materials are similar. A difference in the pore size distribution appears for higher naphthalene content. The solubility of the PAH contained in the material is affected by the ionic strength and by the presence of a co-solvent; the solution pH does not influence PAH solubility. The solubility of the major mineral species is not influenced by the presence of the two PAH nor by the presence of the methanol as co-solvent in the range of the tested material compositions. In the case of the leaching of a monolith material the main transport mechanism is the diffusion in the porous system. For both mineral and organic species we observed at least two dynamic domains. At the beginning of the leaching process the released flux is due to the surface dissolution and to the diffusion of the main quantity dissolved in the initial pore solution. The second period is governed by a stationary regime between dissolution in pore water and diffusion. The model, coupling transport and chemical phenomena in the pore solution, at the monolith surface and in the leachate simulates satisfactory the release for both mineral and organic species.
本文旨在研究含有有机污染物（多环芳烃：萘和菲）的不同多孔材料的浸出行为。将无机材料长期浸出行为的评估方法扩展至水泥固化有机污染物。基于考虑环境因素、基质和污染物特性的情景方法，所应用的方法由适应性平衡和动态浸出试验组成。确定了不同物理和化学机制的贡献并对浸出行为进行了建模。分析的参考材料和污染材料的物理参数相似。对于较高的萘含量，孔径分布出现差异。材料中所含多环芳烃的溶解度受离子强度和共溶剂存在的影响；溶液pH值不影响多环芳烃的溶解度。在所测试的材料组成范围内，主要矿物种类的溶解度不受两种多环芳烃存在的影响，也不受甲醇作为共溶剂存在的影响。对于整体材料的浸出，主要传输机制是在多孔系统中的扩散。对于矿物和有机物种，我们至少观察到两个动态区域。在浸出过程开始时，释放通量归因于表面溶解以及溶解在初始孔隙溶液中的主要量的扩散。第二个阶段由孔隙水中溶解和扩散之间的稳定状态控制。该模型耦合了孔隙溶液、整体表面和渗滤液中的传输与化学现象，令人满意地模拟了矿物和有机物种的释放。
