辣椒秸秆对刚果红染料的吸附性质

Adsorption of Congo red by the pepper stalk waste

以辣椒秸秆为原料制备生物吸附剂,研究辣椒秸秆吸附剂对染料刚果红(CR)的吸附性质。研究了改性和吸附条件对吸附效果的影响,并拟合其吸附热力学、动力学和等温线模型。正交试验极差分析表明:吸附效果影响因素的主次顺序为,吸附剂用量>初始染料浓度>吸附温度>吸附时间。最佳工艺为:辣椒秸秆1.20 g,CR质量浓度300 mg/L,吸附温度70℃、时间240 min。拟合得出吸附符合准二级反应动力学模型,属于化学吸附;符合Langmuir吸附等温式,可初步判断吸附发生在辣椒秸秆的外表面,属于单分子层化学吸附。热力学计算表明,该吸附过程属于自发的吸热反应。

The pepper stalk was used as raw material to prepare the biological adsorbent for the Congo red dye solution adsorption. The effects of the modification and adsorption conditions on adsorption efficiency were studied,and the adsorption thermodynamics,adsorption kinetics and adsorption isotherm model were established. The orthogonal experiment analysis indicated that the influence from high to low follows adsorbent dosage,initial dye concentration,adsorption temperature and time. The results showed that the optimized process： adsorption temperature was 70℃,adsorption time was 240 min,the initial dye concentration was 300 mg/L and the adsorbent dosage was 1. 20 g. By fitting the adsorption kinetics,the adsorption process was according with the quasi-two-order reaction kinetic model,which was controlled by chemical adsorption. The fit of the adsorption isotherm model conformed to the Langmuir adsorption isotherm,and the adsorption processes belong to monolayer adsorption. The thermodynamic calculations showed that the adsorption process was endothermic spontaneous reaction.