Phyllosticta capitalensis粉末菌剂对孔雀石绿染料的吸附动力学分析

Study on adsorption process of malachite green dye by powdered Phyllosticta capitalensis

将富含多糖的内源真菌Phyllosticta capitalensis的粉末菌剂作为生物吸附剂,对孔雀石绿染料废水进行吸附处理。分别考察了粉末剂量、孔径大小、染料的初始浓度、pH值、背景离子强度和金属离子等因素对P.capitalensis粉末菌剂吸附孔雀石绿染液的影响。通过对实验数据进行吸附动力学和等温吸附模型的拟合,以及对吸附前后的吸附剂进行红外光谱扫描,探究P.capitalensis粉末菌剂对孔雀石绿染料的吸附机理。结果表明:粉末菌剂的最大单位吸附量为19.61 mg·g^(-1)。当pH=6时吸附效果更佳,且在一定范围内粉末菌剂的粒径越大,染料浓度越高,吸附效果越好。而较高的离子强度与金属离子对P.capitalensis粉末菌剂吸附孔雀石绿溶液则起一定的抑制作用。动力学和等温吸附模型拟合分析表明该实验吸附过程符合准二级动力学吸附模型与Koble-Corrigan等温吸附模型,说明该吸附过程属于多层化学吸附,红外光谱扫描结果表明是粉末菌剂中的多糖羟基和羰基与染料发生反应。

The powder bacterial agent of polysaccharide-rich endogenous fungus Phyllosticta capitalensis was used as a biological adsorbent to treat malachite green dye wastewater.The effects of powder dosage,pore size,initial concentration of dye,pH value,background ion strength,and metal ions on the adsorption of malachite green by P.capitalensis powder were investigated.The adsorption kinetics and isothermal adsorption model were fitted to the experimental data.The infrared spectra of the adsorbents before and after adsorption were scanned to explore the adsorption mechanism of malachite green dye in P.capitalensis powder bacterial agent.The results showed that the maximum unit adsorption capacity of powdered bacteria was 19.61 mg·g^(-1).When pH=6,the adsorption effect is better.In a certain range,the larger pore size of the powder bacterial agent and the higher dye concentration leads to the better the adsorption effect.On the other hand,the higher ionic strength and the metal ions have an inhibited effect on adsorption.The fitting results of kinetics and isothermal adsorption model show that the adsorption process accords with the pseudo-second-order kinetic adsorption model and Koble-Corrigan isothermal adsorption model,indicating that the adsorption process belongs to multi-layer chemical adsorption.Infrared spectrum scanning results show that the hydroxyl and carbonyl groups of polysaccharides react with dyes.