Ozer Dursun, Dursun Gülbeyi, Ozer Ahmet
Department of Chemical Engineering, Firat University, 23279 Elazig, Turkey.
J Hazard Mater. 2007 Jun 1;144(1-2):171-9. doi: 10.1016/j.jhazmat.2006.09.092. Epub 2006 Oct 11.
Dyes are colour organic compounds which can colorize the other substances. These substances usually presents in the effluent water of many industries, such as textiles, leather, paper, printing and cosmetics. To observe the potential feasibility of removing colour, peanut hull as an agricultural by-product was dehydrated with sulphuric acid (DPH) and used for adsorption of methylene blue (MB) from aqueous solution. The effects of various parameters such as initial methylene blue concentrations, temperatures and particle sizes were examined and optimal experimental conditions were determined. Adsorption data were well described by the Langmuir model, although they could be modelled by the Freundlich model as well. The adsorption process followed the pseudo-second order kinetic model. The mass transfer model as intraparticle diffusion was applied to the experimental data to examine the mechanisms of rate controlling step. It was found that at the higher initial MB concentration, intraparticle diffusion is becoming significant controlling step. The thermodynamic constants of the adsorption process were also evaluated by using the Langmuir constants related to the equilibrium of adsorption at different temperatures. The results in this study indicated that dehydrated peanut hull was a good adsorbent for removing methylene blue.
染料是能够使其他物质着色的有色有机化合物。这些物质通常存在于许多行业的废水中，如纺织、皮革、造纸、印刷和化妆品行业。为了观察去除颜色的潜在可行性，将花生壳这种农业副产品用硫酸脱水（DPH），并用于从水溶液中吸附亚甲基蓝（MB）。研究了初始亚甲基蓝浓度、温度和粒径等各种参数的影响，并确定了最佳实验条件。吸附数据用朗缪尔模型能很好地描述，不过也能用弗伦德里希模型进行模拟。吸附过程遵循准二级动力学模型。将颗粒内扩散传质模型应用于实验数据，以研究速率控制步骤的机制。研究发现，在较高的初始MB浓度下，颗粒内扩散成为显著的控制步骤。还利用与不同温度下吸附平衡相关的朗缪尔常数评估了吸附过程的热力学常数。本研究结果表明，脱水花生壳是去除亚甲基蓝的良好吸附剂。
