Stefanova R Y
Department of Water Supply, Sewerage and Water Treatment, University of Architecture, Civil Engineering and Geodesy, 1421 Sofia, Bulgaria.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2001;36(3):293-306. doi: 10.1081/ese-100102923.
A sorption active product has been obtained from Bulgarian clay marl by thermal activation at 750 degrees C. The modified aluminosilicate material is characterized, as well as its use for the removal of metal ions. The effect of the initial metal ion concentration, the contact time, pH, the solution temperature and the ionic strength on the uptake of lead, copper and zinc ions from aqueous solutions were studied in batch experiments. The kinetics of removal of metal ions on modified clay marl appears dependent on the sorbate/sorbent ratio. At low cation concentrations sorption follows a Langmuir isotherm, while at higher sorbate/sorbent ratios the sorption isotherms of metal ions are described by Freundlich's equation. At the pH region of the sorption edge the removal of metal ions by surface complexation and surface precipitation mechanisms is indistinguishable. It is observed that the influence of temperature on the uptake ability of the clay marl is most considerable up to 40 degrees C. These studies show that the thermally modified clay marl can be successfully used for removal of metal ions from water solutions in a wide range of concentrations.
通过在750摄氏度下进行热活化，从保加利亚粘土泥灰岩中获得了一种吸附活性产物。对改性铝硅酸盐材料进行了表征，并研究了其用于去除金属离子的用途。在批量实验中研究了初始金属离子浓度、接触时间、pH值、溶液温度和离子强度对从水溶液中摄取铅、铜和锌离子的影响。改性粘土泥灰岩上金属离子的去除动力学似乎取决于吸附质/吸附剂的比例。在低阳离子浓度下，吸附遵循朗缪尔等温线，而在较高的吸附质/吸附剂比例下，金属离子的吸附等温线由弗伦德利希方程描述。在吸附边缘的pH区域，通过表面络合和表面沉淀机制去除金属离子的情况难以区分。据观察，温度对粘土泥灰岩摄取能力的影响在高达40摄氏度时最为显著。这些研究表明，热改性粘土泥灰岩可成功用于在广泛的浓度范围内从水溶液中去除金属离子。
