Arami Mokhtar, Limaee Nargess Yousefi, Mahmoodi Niyaz Mohammad, Tabrizi Nooshin Salman
Environmental Science and Engineering Department, Iran Color Research Center, Tehran, Iran; Textile Engineering Department, Tehran Polytechnic University, Tehran, Iran.
J Colloid Interface Sci. 2005 Aug 15;288(2):371-6. doi: 10.1016/j.jcis.2005.03.020.
The use of low-cost and ecofriendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. Orange peel was collected from the fields of orange trees in the north of Iran and converted into a low-cost adsorbent. This paper deals with the removal of textile dyes from aqueous solutions by orange peel. Direct Red 23 (DR23) and Direct Red 80 (DR80) were used as model compounds. The adsorption capacity Q0 was 10.72 and 21.05 mg/g at initial pH 2. The effects of initial dye concentration (50, 75, 100, 125 mg/l), pH, mixing rate, contact time, and quantity of orange peel have been studied at 25 degrees C. The Langmuir and Freundlich models were used for this study. It was found that the experimental results show that the Langmuir equation fit better than the Freundlich equation. The results indicate that acidic pH supported the adsorption of both dyes on the adsorbent. Orange peel with concentrations of 8 and 4 g/l has shown adsorption efficiencies of about 92 and 91% for DR23 and DR80, respectively. Furthermore, adsorption kinetics of both dyes was studied and the rates of sorption were found to conform to pseudo-second-order kinetics with a good correlation (R > or = 0.998). Maximum desorption of 97.7% for DR23 and 93% for DR80 were achieved in aqueous solution at pH 2. Finally, the effect of adsorbent surface was analyzed by scanning electron microscope (SEM). SEM images showed reasonable agreement with adsorption measurements.
人们已经研究了使用低成本且环保的吸附剂，作为当前从废水中去除染料的昂贵方法的理想替代方案。橙皮取自伊朗北部的橙子园，并被转化为一种低成本吸附剂。本文探讨了用橙皮去除水溶液中的纺织染料。直接红23（DR23）和直接红80（DR80）被用作模型化合物。在初始pH值为2时，吸附容量Q0分别为10.72和21.05 mg/g。在25摄氏度下，研究了初始染料浓度（50、75、100、125 mg/l）、pH值、混合速率、接触时间和橙皮用量的影响。本研究使用了朗缪尔模型和弗伦德利希模型。结果发现，实验结果表明朗缪尔方程比弗伦德利希方程拟合得更好。结果表明，酸性pH值有利于两种染料在吸附剂上的吸附。浓度为8和4 g/l的橙皮对DR23和DR80的吸附效率分别约为92%和91%。此外，还研究了两种染料的吸附动力学，发现吸附速率符合伪二级动力学，相关性良好（R≥0.998）。在pH值为2的水溶液中，DR23的最大解吸率为97.7%，DR80的最大解吸率为93%。最后，通过扫描电子显微镜（SEM）分析了吸附剂表面的影响。SEM图像与吸附测量结果显示出合理的一致性。
