【作者】 吴波； 张进成； 王洋； 刘毅； 魏凤玉；

【Author】 Bo Wu;Jincheng Zhang;Yang Wang;Yi Liu;Fengyu Wei;School of Chemistry and Chemical Engineering,Hefei University of Technology;

【机构】 合肥工业大学化学与化工学院；

【摘要】 采用硝酸改性-高温活化法对废弃的兰炭末进行处理,对改性前后的兰炭末进行了SEM和BET表征,测定了改性后的兰炭末对对硝基苯酚的吸附性能,通过静态吸附实验研究了改性兰炭末对对硝基苯酚的吸附平衡和动力学特征。结果表明,兰炭末经改性后表面粗糙度明显增加,孔道明显增多,总孔容和比表面积分别增加了7.1倍和4.3倍;Langmuir方程可较好地描述对硝基苯酚在改性兰炭末上的吸附平衡,特征分离系数RL为0~1,为优惠吸附,温度升高有利于吸附的进行,328K下平衡吸附量达158.5mg/g;动力学研究表明,对硝基苯酚在改性兰炭末上的吸附过程符合HO准二级动力学模型,颗粒外的液膜扩散是决定吸附速率的控制步骤,吸附过程的表观活化能Ea为9.825 k J·mol-1。更多还原

【Abstract】 The abandoned fine blue-coke was modified by the nitrate treatment- high temperature activation process. The raw materials and modified fine blue-coke(MFBC) were characterized by SEM and BET. The adsorption capacity of MFBC toward pnitrophenol was measured. The adsorption equilibrium isotherms and kinetic curves of p-nitrophenol onto MFBC were investigated by the batch sorption experiments. The Langmuir and Freundlich adsorption models were used for mathematical description of pnitrophenol onto MFBC. Two kinetic models including Lagergren pseudo-first-order and HO pseudo-second-order equation were selected to follow the adsorption processes of p-nitrophenol onto MFBC. The adsorption kinetics data were fitted by the liquid-film diffusion, the particle inner diffusion and the adsorption reaction control equation, respectively. Meanwhile, the apparent activation energy in the process of adsorption was calculated by the Arrhenius equation, and the control step of adsorption rate was determined. The results showed that the surface roughness of MFBC increased obviously. The total pore volume and specific surface area increased by 7.1 and 4.3 times, respectively. The equilibrium data were found to follow closely the Langmuir adsorption isotherm. The adsorption process was favorable adsorption as the feature separation factor RL was between 0 and 1. In addition, the increment in temperature was beneficial for the adsorption process. The kinetic analysis demonstrated that the adsorption of p-nitrophenol onto MFBC could be best described by the HO pseudo-second-order equation. The liquid-film diffusion outside of particles is the main control step. The apparent active energy of the adsorption process(Ea) was 9.825 k J/mol. The MFBC exhibited good adsorption performance toward p-nitrophenol. The maximum sorption capacity of MFBC onto p-nitrophenol was 158.5 mg/g at 328 K. These results clearly indicate the modified fine blue-coke(MFBC) as a low-cost adsorbent for treatment of wastewater containing pnitrophenol have a potential industrial application.更多还原