Department of Environmental Health, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
J Hazard Mater. 2010 Nov 15;183(1-3):724-30. doi: 10.1016/j.jhazmat.2010.07.086. Epub 2010 Jul 30.
Many waste materials have been evaluated for their efficacy in removing different classes of contaminants from water and wastewater in order to improve the cost-effectiveness of adsorption. In the present study, pistachio green hull wastes were investigated as a potential adsorbent for the removal of cyanide from a synthetic wastewater. The effects of a selection of the most significant parameters (pH, adsorbent dose, cyanide concentration and contact time) were initially evaluated based on the percentage of cyanide removed from the wastewater. At an optimum pH of 10, over 99% removal of 100 mg/L cyanide was obtained for an adsorbent dose of 1.5 g/L after a 60 min contact time. Kinetic evaluation indicated that the adsorption of cyanide ions onto the pistachio hulls clearly followed the pseudo-second order rate reaction. The equilibrium assessment illustrated that the Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 156.2 mg/g. The sorption of cyanide ions onto the introduced adsorbent was inferred to be a chemosorption process with intraparticle diffusion as the most important step controlling the overall process rate. Accordingly, the pistachio hull waste is introduced as an efficient and low-cost adsorbent for removal of different concentrations of cyanide from water and wastewater.
为了提高吸附的成本效益，许多废物材料已被评估用于去除水中和废水中不同类型的污染物的效果。在本研究中，研究了开心果绿色外壳废物作为一种从合成废水中去除氰化物的潜在吸附剂。最初根据废水去除的氰化物百分比评估了选择的最显著参数（pH 值、吸附剂剂量、氰化物浓度和接触时间）的影响。在最佳 pH 值为 10 时，在 60 分钟接触时间后，当吸附剂剂量为 1.5g/L 时，可去除 100mg/L 氰化物的 99%以上。动力学评估表明，氰化物离子在开心果壳上的吸附明显遵循拟二级速率反应。平衡评估表明，Langmuir 模型最适合实验数据，其最大吸附容量为 156.2mg/g。推断氰化物离子在引入的吸附剂上的吸附是一种化学吸附过程，颗粒内扩散是控制整个过程速率的最重要步骤。因此，开心果壳废物被引入为一种从水中和废水中去除不同浓度氰化物的有效且低成本的吸附剂。
