Equilibrium sorption of methylene blue using mansonia wood sawdust as biosorbent
Equilibrium sorption of methylene blue using mansonia wood sawdust as biosorbent
复制标题
DOI：
10.5004/dwt.2009.433
复制
发表时间：
2009-03
影响因子：
1.1
通讯作者：
A. Ofomaja
中科院分区：
文献类型：
--
作者：
A. Ofomaja
研究了曼森木木屑作为低成本吸附剂对水溶液中碱性染料亚甲基蓝的吸附去除效果。采用间歇吸附法研究了木屑粒径对亚甲基蓝平衡吸附量的影响。在26 °C下使用不同粒径（150、250、350、450和550 μm）的曼氏木锯屑测定吸附等温线，并使用Langmuir、Freundlich、Tempkin和Dubininin-Radushkevich等温线对所获得的实验数据进行建模。结果表明，锯屑颗粒大小有很强的影响，染料去除的百分比和上的染料吸附量每克锯屑从120 mg/dm 3染料溶液。当木屑粒径从150 μm增加到550 μm时，上染百分率从93.57%降低到29.50%，每克木屑吸附的染料量从28.07 mg/g降低到8.85 mg/g。等温线数据被认为是很好地描述的Langumir，Tempkin和Dubininin-Radushkevich等温线模型。采用粒径为150 μm的木屑，由Langmuir方程计算的单分子层容量为33.44 mg/g。由Tempkins法计算的吸附平衡常数Kt随木屑粒径的增大而减小，由Dubininin-Radushkevich等温式计算的吸附自由能为12.91 ~ 13.89mol2kJ-2，表明吸附机理为离子交换。在不同染料初始浓度下，吸附平衡容量与吸附结束时pH值变化（ΔH +）之间也建立了数学关系，支持了亚甲基蓝染料在曼氏木锯屑上的吸附是通过离子交换实现的。在低pH条件下实现吸附的染料分子到溶液中的解吸。
The potential use of mansonia wood sawdust as low-cost adsorbent for the sorptive removal of basic dye, methylene blue, from aqueous solution has been studied. The effect of sawdust particle size on the equilibrium methylene blue uptake was examined using batch sorption technique. Adsorption isotherm was determined using various particle sizes (150, 250, 350, 450 and 550 μm) of mansonia sawdust at 26 °C and the experimental data obtained were modeled using the Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich isotherms. The results revealed that the sawdust particle size has a strong influence on the percentage dye removal and on the amount of dye adsorbed per gram of sawdust from a 120 mg/dm 3 dye solution. Increasing sawdust particle size from 150 to 550 μm reduced the percentage dye uptake from 93.57% to 29.50 % and amount of dye adsorbed per gram of sawdust from 28.07 to 8.85mg/g. The isotherm data were found to be well described by the Langumir, Tempkin and Dubinin-Radushkevich isotherm models. The monolayer capacity calculated from the Langmuir equation is given as 33.44 mg/g using sawdust of particle size 150 μm. The equilibrium binding constant K t calculated from the Tempkins was reduced with increasing sawdust particle size from 150 to 550 μm, while the mean free energy of sorption per mole of sorbate calculated from the Dubinin-Radushkevich isotherm was in the range 12.91 to 13.89 mol 2 kJ -2 , suggesting that the sorption mechanism was by ion exchange. A mathematical relationship was also drawn between the equilibrium sorption capacity and the change in pH (ΔH + ) at the end of the isotherm experiments with varying initial dye concentration, supporting the fact that sorption of methylene blue dye on mansonia sawdust is by ion exchange. Desorption of sorbed dye molecules into solution was achieved at low pH conditions.