鸡蛋膜对苏丹红Ⅰ的吸附行为及机制研究

Adsorption behavior and mechanism of Sudan I by eggshell membrane.

本文研究了厨余废弃物鸡蛋膜对食品污染物苏丹红I的吸附效果,通过条件优化及Zeta电位分析法考察了p H、吸附剂投入量、离子强度对吸附效果的影响,结果表明:在p H=6,10 g·L-1吸附剂投入量及1%Na Cl条件下吸附效果最佳,吸附平衡时间为140 min,平衡吸附量为1.25 mg·g-1;另外,对等温吸附过程进行了Langmuir、Freundlich、Temkin模型拟合及热力学参数计算,发现三种吸附模型均能较好地描述鸡蛋膜对苏丹红I的吸附过程(R2为0.86~0.99),但Freundlich模型的拟合效果更好(R2>0.97);ΔG<0,ΔH>0,ΔS>0,表明苏丹红I与鸡蛋膜表面吸附位点在氢键及偶极间作用力下发生非均匀吸附,且该过程为吸热及熵推动的自发过程;对吸附过程进行了动力学模型拟合,发现准二级反应动力学方程拟合效果较好。结论:鸡蛋膜吸附剂对苏丹红I具有一定的吸附效果。

Adsorption of Sudan I by the eggshell membrane was investigated with respect to various parameters such as pH, amount of adsorbent and ionic strength.The Results showed that the best adsorption capacity was found at 10 g· L^-1 eggshell membrane, pH6,1% NaCl.The adsorption equilibrium time was 140 min and the adsorbing capacity was 1.25 mg· L^-1.Models of Langmuir, Freundlich and Temkin were used to fit the adsorption isotherms, all of the three models provided good fitting to the adsorption process （R2 was 0,86-0.99）, but Freundlich model showed relatively better correlation coefficient （R2 〉 0.97）. The adsorption thermodynamic parameters showed that Gibbs free energy （AG） 〈 0, enthalpy （AH） 〉 0, and entropy （AS） 〉 0, indicating that the adsorption of Sudan I occured on heterogeneous sites with non-uniform distribution of energy levels and the adsorption process was spontaneous, endothermic and entropy increasing.On the other hands, Kinetics of the sorption process were also investigated and the adsorption kinetic process provided good fitting with the Lagergren pseudo-second order kinetic model.In conclusion, eggshell membrane have a good adsorption effect to Sudan I.