功能化锌金属有机骨架对刚果红染料的吸附

Adsorption of Congo red dye by organic skeleton of functional zinc metal

为了提高染料废水中刚果红的吸附量和脱色率,从而减少其对环境的污染,以锌金属有机骨架(MOF-5)和功能化锌金属有机骨架(EDA/MOF-5)作为吸附材料,探讨其对刚果红的吸附性能;研究染料浓度、温度、pH值、吸附时间和离子强度对吸附性能的影响,用Langmuir和Freundlich模型对其吸附行为进行描述,并对其吸附动力学进行了探究.结果表明:EDA/MOF-5较于MOF-5对刚果红的吸附量和脱色率分别提升了13.19 mg/g和14%;金属有机骨架MOF-5在弱碱性的条件下更容易吸附水中的刚果红染料,EDA/MOF-5受pH值的影响较小;在试验范围内,随着刚果红初始浓度和温度的升高,EDA/MOF-5对刚果红的吸附量也随之增大,当刚果红浓度为80 mg/L时,EDA/MOF-5对其吸附量和脱色率分别达到78.36 mg/g和98%;由于其他离子的加入,其与染料分子相互竞争吸附位点,对于刚果红的吸附有一定的抑制作用;研究表明Freundlich模型更适合描述该吸附过程;该吸附过程更符合拟二级动力学方程.

In order to improve the adsorption and decoloring rate of Congo red in dye wastewater,and reduce its pollution to the environment,zinc metal organic skeleton(MOF-5)and functional zinc metal organic skeleton(EDA/MOF-5)was used as adsorption material to discuss the adsorption of Congo red.The effects of dye concentration,temperature,pH,adsorption time and ionic strength on the properties of adsorption,the adsorption behavior of Langmuir and Freundlich were described,and the adsorption kinetics was explored.The results showed that the adsorption and decolorization rate of EDA/MOF-5 were respectively increased by 13.19 mg/g and 14%respectively.The metal organic skeleton MOF-5 is easier to adsorb the Congo red dye under weak alkaline conditions,and EDA/MOF-5 was less affected by pH.Within the scope of the experiment,with the increase of initial concentration of Congo red and temperature,the adsorption quantity of the EDA/MOF-5 on the Congo red was also increased,the EDA/MOF-5 of its adsorption capacity and decolorization rate was 78.36 mg/g and 98%respectively when the concentration of Congo red was 80 mg/L.Because of the addition of other ions,it competes with the dye molecules for adsorption sites and has a certain inhibitory effect on the adsorption of Congo red.The study showed that the Freundlich model was more suitable for describing the adsorption process and the adsorption process was more consistent with the second order kinetics equation.