粉煤灰/镧/壳聚糖复合材料对模拟染料废水的吸附效果

Research on the adsorption effect of coal ash/lanthanum/chitosan composite on the simulated dye waste water

针对印染废水难处理的问题,将经镧改性的壳聚糖负载在粉煤灰上,制备出粉煤灰/镧/壳聚糖复合材料。考查了pH值、吸附时间、初始质量浓度、温度等因素对其吸附效果的影响,并利用吸附动力学、吸附热力学和等温吸附模型探讨其吸附机制。结果表明:粉煤灰/镧/壳聚糖复合材料对酸性橙溶液的吸附速率较快,60 min内达到吸附平衡,且pH值为6时,投加量为8 g/L时,25℃的条件下吸附效果最好,脱色率达到90%以上。粉煤灰/镧/壳聚糖复合材料对酸性橙溶液的吸附更加符合Freundlich等温模型和准二级吸附速率方程,其吸附过程由化学吸附和颗粒内扩散共同控制,吸附过程为自发进行。

To solve the problem of the difficultly in treating printing and dyeing waste water,coal ash/lanthanum/chitosan composites was prepared by loading the lanthanum modified chitosan on coal ash.The influence of pH,adsorption time,initial concentration,temperature and other factors on its adsorption effect were investigated,and the adsorption mechanism was discussed by using adsorption kinetics,adsorption thermodynamics and isothermal adsorption model.The result show that the adsorption rate of coal ash/lanthanum/chitosan composites to acid orange solution is fast,which reaches the adsorption equilibrium in 60 min.Meanwhile,the optimum adsorption effect can be achieved when the pH value is 6,the added dosage is 8 g/L and the temperature is 25℃,in which the decolorization rate is more than 90%.The coal ash/lanthanum/chitosan composites adsorption of acid orange solution is more in line with Freundlich isothermal model and quasi second-order adsorption rate equation.More importantly,the adsorption process is controlled by the chemical adsorption and the diffusion in particle,in which the adsorption process is spontaneous.