氨基化石墨烯/聚乙烯亚胺复合材料对甲基橙和刚果红的吸附性能研究

Study on Adsorption Performance of Aminated Graphene/Polyethyleneimine Composites for Methyl Orange and Congo Red

含有合成染料的废水具有成分复杂、可生物降解性能差、COD高等特点受到了广泛研究。使用氨基化石墨烯/聚乙烯亚胺复合材料(GO-NH2/PEI)对典型的阴离子染料甲基橙和刚果红进行吸附,最佳吸附条件为:染料含量150 mg/L、吸附剂用量0.5 g/L、溶液p H值为6、吸附温度318 K和吸附时间240 min时,GO-NH2/PEI对甲基橙和刚果红的吸附量可达282.82 mg/g和240.22 mg/g,循环使用5次,仍可保持约90%的最大吸附量。并使用吸附等温线、吸附热力学、吸附动力学等对吸附过程进行拟合,结果表明:GO-NH2/PEI对阴离子染料的吸附主要为单层化学吸附,是吸热熵增的自发过程。GO-NH2/PEI作为多孔材料,合成染料分子越小,越容易扩散进复合材料内部与活性官能团缔合,吸附性能越好。

Wastewater containing synthetic dyes with complex composition,poor biodegradability and high COD has been widely studied.The adsorption of typical anionic dyes,methyl orange and Congo red,using aminated graphene/polyethyleneimine composites(GO-NH2/PEI)was carried out under the following optimal adsorption conditions:dye content was 150 mg/L,adsorbent dosage was 0.5 g/L,solution pH was 6,adsorption temperature was 318 K and adsorption time was 240 min,and the adsorption capacity of methyl orange and Congo red by GO-NH2/PEI could reach 282.82 mg/g and 240.22 mg/g,and the maximum adsorption amount of about 90%could still be maintained after 5 times of recycling.The results showed that the adsorption of anionic dyes by GO-NH2/PEI was mainly monolayer chemisorption,which is a spontaneous process of heat absorption and entropy increase.As GO-NH2/PEI was a porous material,the smaller the molecule of synthetic dye,the easier it was to diffuse into the interior of the composite and join with the active functional group,and the better adsorption performance.