Pickering乳液模板多孔WG-g-PNaA水凝胶去除水体中的亚甲基蓝  

Methylene blue removal by the porous WG-g-PNaA hydrogel based on Pickering emulsion template

作　　者：王轩栋 施小宁 杨秀娟 WANG Xuandong;SHI Xiaoning;YANG Xiujuan(College of Pharmacy,Gansun University of Chinese Medicine,Lanzhou 730000,China)

机构地区：[1]甘肃中医药大学药学院,兰州730000

出　　处：《环境工程学报》2020年第12期3270-3279,共10页Chinese Journal of Environmental Engineering

基　　金：甘肃省高等学校创新能力提升项目(2019A-077)。

摘　　要：为拓展小麦加工副产物麦麸蛋白(WG)在印染废水处理工业中的应用,以其中的醇溶蛋白稳定的O/W型Pickering乳液为孔模板,WG与AA原位自由基接枝聚合,制备了多孔小麦麸质蛋白-g-聚丙烯酸钠(WGg-PNaA)水凝胶。通过FT-IR、FESEM表征手段对合成的水凝胶进行结构和表面形貌表征,考察了其对水体中亚甲基蓝(MB)的去除性能。结果表明:WG与PAA链成功接枝聚合,Pickering乳液滴被洗除后在WG-g-PNaA水凝胶网络中留下规整的连续孔隙,BET比表面积为18.04 m^2·g^−1;在溶液pH=9.0,初始浓度C0≤300 mg·L^−1时,多孔WG-g-PNaA水凝胶对MB的去除率可达98.5%以上,其等温吸附过程符合Langmuir单层吸附模型,饱和吸附量为2144.2 mg·g^−1;吸附热力学研究结果表明:温度对吸附影响较小,吸附动力学数据符合准二级动力学模型,物理化学静电吸附为速率控制步骤;但吸附初期Pickering乳液致孔凝胶的粒子内扩散模型的K1d(28.59)远大于无Pickering乳液致孔凝胶的K1d(12.89),这说明凝胶网络中的孔隙在吸附初期有利于MB分子扩散传质,提高吸附速率。研究结果可为WG在印染废水处理中的应用提供参考。To expand the application of wheat gluten(WG),a byproducts from wheat process,in dyeing wastewater treatment industry,gliadin stabilized O/W-Pickering emulsion was taken as template,the in situ free radical grafted polymerization of WG and AA was conducted to prepare a novel porous hydrogel,named as wheat gluten-graft-sodium polyacrylate(WG-g-PNaA)hydrogel.The structure and morphology of the porous WG-g-PNaA hydrogel was characterized by FT-IR and FESEM,and the performance on methylene blue removal by the WG-g-PNaA hydrogel was studied.The results showed that a successful grafted polymerization between WG and PAA chain,the regular and continuous pores left in WG-g-PNaA hydrogel network after removing Pickering emulsion drops by washing.The BET specific surface area was 18.04 m^2·g^−1.At the initial pH 9.0 and MB initial concentration not higher than 300 mg·L^−1,the MB removal rate could reach over 98.5%by porous WG-g-PNaA hydrogel.The adsorption process accorded with Langmuir single-layer adsorption model,the corresponding saturated adsorption amount was 2144.2 mg·g^−1.The adsorption thermodynamics indicated that temperature had slight effect on adsorption.Adsorption kinetics followed the pseudo-second-order kinetic model,the rate control step was physicochemical electrostatic adsorption.However,the intra-particle diffusion model coefficient K1d(28.59)of the Pickering emulsion pore hydrogel at the initial adsorption stage was much higher than that of the non-Pickering emulsion pore hydrogel(12.89).This result indicated that the pores in the hydrogel network were benefited for the diffusion of MB molecules and improving the initial adsorption rate at the initial adsorption stage.This can provide reference for expand the application of wheat processing by-product in dyeing wastewater treatment.

关 键 词：小麦麸质蛋白 Pickering乳液模板 多孔水凝胶 亚甲基蓝去除 

分 类 号：X703[环境科学与工程—环境工程]