兰炭改性及其对甲基橙吸附性能研究

Research on the modification of semi-coke and its adsorption properties of methyl orange

文章采用氯化锌水溶液对废弃的兰炭末进行改性,研究了改性兰炭末对水溶液中甲基橙(MO)吸附性能的影响,并探讨其吸附机理。结果表明:改性兰炭末对MO的吸附量随着温度升高而降低,吸附为放热过程,在298K时达372.1mg/g;吸附等温线呈S型,不是一个简单的单分子层吸附,低质量浓度的MO溶液在改性兰炭末上的吸附符合Freundlich模型,高质量浓度时则符合BET多分子层吸附;准二级动力学方程可较好地描述其吸附动力学过程,颗粒内扩散是吸附速率控制步骤,表观活化能Ea为19.21kJ/mol。

The abandoned fine semi-coke（FSC） was modified by zinc chloride aqueous solution .The modified process parameters and adsorption mechanism of methyl orange （M O） onto the modified fine semi-coke（MFSC） were studied .The results showed that the adsorption process was exothermic be-cause the adsorption capacity decreased with the increase of temperature .The maximum adsorption capacity of MO onto MFSC was 372 .1 mg/g at 298 K .The adsorption isotherm was an S type ,and the process was not a simple monolayer adsorption .The equilibrium data followed closely the Freun-dlich adsorption model when the concentration of MO was low and conformed with the BET multilayer adsorption model when the concentration of MO was high .The kinetic analysis demonstrated that the adsorption of MO onto MFSC could be best described by the pseudo-second-order equation .The parti-cle diffusion was the main control step and the apparent active energy of the adsorption process （Ea ） w as 19 .21 kJ/mol .