Li Yujiang, Gao Baoyu, Wu Tao, Wang Biao, Li Xia
School of Environmental Science & Engineering, Shandong University, Jinan, PR China.
J Hazard Mater. 2009 May 30;164(2-3):1098-104. doi: 10.1016/j.jhazmat.2008.09.009. Epub 2008 Sep 7.
The use of aluminum magnesium mixed metal hydroxide (MMH) as adsorbent to remove Reactive Brilliant Red K-2BP (RBR K-2BP), as a model anionic dye, from aqueous solution was investigated. MMH was prepared by coprecipitation and was characterized by XRD, TEM and average particle diameter. Adsorption experiments were carried out as a function of pH, contact time, concentration of dye, adsorbent dosage, and temperature. The results showed that MMH was particularly effective to remove RBR K-2BP, and that the effective pH range for the dye removal was between 4.0 and 11.0, but at pHs lower than 4, dissolution of MMH took place. A significant decline of dye adsorption occurred at pHs above the isoelectric point (IEP). The adsorption of RBR K-2BP on MMH reached equilibrium within 4h. The appropriate adsorbent dosage was 1000 mg/L. The interaction between the surface sites of MMH and the dye ions may be a combination of both anion exchange and surface complexation. Three kinetic models have been evaluated to fit the experimental data. It was shown that the pseudo-second-order model best described the adsorption kinetics of RBR K-2BP on MMH. The equilibrium isotherm showed that the adsorption of RBR K-2BP onto MMH was consistent with the Langmuir and Freundlich equations. And the saturated adsorption capacity of MMH for RBR K-2BP was 657.5mg/g. The adsorption process was endothermic in nature. MMH displayed superior treatment efficiency to the industrial dye effluents from a printing and dyeing plant with a removal efficiency of 93.8-96.7% for colored materials and 77.9-83.6% for COD.
研究了用铝镁混合金属氢氧化物（MMH）作为吸附剂从水溶液中去除活性艳红K-2BP（RBR K-2BP）这种典型阴离子染料的情况。MMH通过共沉淀法制备，并通过X射线衍射（XRD）、透射电子显微镜（TEM）和平均粒径进行表征。吸附实验根据pH值、接触时间、染料浓度、吸附剂用量和温度进行。结果表明，MMH对去除RBR K-2BP特别有效，去除该染料的有效pH范围在4.0至11.0之间，但在pH值低于4时，MMH会发生溶解。在高于等电点（IEP）的pH值下，染料吸附量显著下降。RBR K-2BP在MMH上的吸附在4小时内达到平衡。合适的吸附剂用量为1000 mg/L。MMH表面位点与染料离子之间的相互作用可能是阴离子交换和表面络合两者的结合。评估了三种动力学模型以拟合实验数据。结果表明，准二级模型最能描述RBR K-2BP在MMH上的吸附动力学。平衡等温线表明，RBR K-2BP在MMH上的吸附符合朗缪尔和弗伦德利希方程。MMH对RBR K-2BP的饱和吸附容量为657.5mg/g。吸附过程本质上是吸热的。MMH对印染厂工业染料废水显示出优异的处理效率，对有色物质的去除效率为93.8 - 96.7%，对化学需氧量（COD）的去除效率为77.9 - 83.6%。
