摘要
以6-羧基葡萄糖、半胱氨酸和水杨酸分别代表二级出水的3种典型污染物多糖(SA)、蛋白质(BSA)和腐殖酸(HA)的分子组成,通过分子动力学(MD)技术,模拟了二级出水典型污染物,与醋酸纤维素(CA)、聚醚砜(PES)、聚偏氟乙烯(PVDF)等3种主流商业膜材料之间的结合能(ΔE),作为对具有特征污染物性质的二级出水,在不同的膜材料上产生膜污染行为的判断依据.MD数据显示:PVDF结构单元与6-羧基葡萄糖和水杨酸分子间的ΔE高于半胱氨酸,而PES结构单元与半胱氨酸分子间的ΔE值高于其它分子间的组合.3种污染物在超滤膜上的过滤通量衰减及膜污染指数,证实了MD对PVDF膜上SA和HA污染性更高,而BSA在PES膜上更易产生膜污染的预测结论;分别对6-羧基葡萄糖、水杨酸、半胱氨酸与3种聚合物结构单元间的ΔE值,与SA、HA、BSA的超滤操作初始通量衰减率间进行了线性拟合,得到的拟合系数分别为0.9981、0.9555、0.7186,说明半胱氨酸作为蛋白质类代表物进行分子模拟尚有一定的不足.
6-carboxy glucose,cysteine and salicylic acid,representing the molecular composition of three typical pollutants in the secondary effluent,polysaccharide(SA),protein(BSA)and humic acid(HA)were used to simulate the binding energy(ΔE)between the secondary effluent and three main commercial membrane materials,cellulose acetate(CA),polyethersulfone(PES),polyvinylidene fluoride(PVDF)by molecular dynamics(MD)technique,which can be used as a basis for judging the membrane fouling behavior of the secondary effluent with characteristic pollutant properties on different membrane materials.The MD data shows that theΔE between the structural unit of the PVDF and 6-carboxyglucose and salicylic acid is higher than that of cysteine,and theΔE value between the PES structural unit and cysteine is higher than that of the other two molecules.The filtration flux attenuation and membrane fouling index of the three pollutants on ultrafiltration membrane confirmed that MD had higher fouling properties to SA and HA on PVDF membrane,while BSA was more likely to produce membrane fouling on PES membrane.TheΔE values between 6-carboxyglucose,salicylic acid,cysteine and the three polymer units were linearly fitted with the initial flux attenuation rate of SA,HA,BSA ultrafiltration operation.The fitting coefficients were 0.9981,0.9555,0.7186,respectively,which indicated that cysteine as a protein representative has some shortcomings in molecular simulation.
作者
孟晓荣
陈嘉智
杨胜
吕永涛
唐卫婷
MENG Xiaorong;CHEN Jiazhi;YANG Sheng;LV Yongtao;TANG Weiting(School of Chemistry and Chemical Engineering,Xi'an University of Architecture and Technology,Xi'an,710055,China;School of Environmental&Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an,710055,China;Key Laboratory of Membrane Separation of Shaanxi Province,Xi'an,710055,China)
出处
《环境化学》
CAS
CSCD
北大核心
2020年第2期397-408,共12页
Environmental Chemistry
基金
陕西省重点产业链(群)项目(2017ZDCXL-GY-07-03)
西安市科技创新引导项目(201805033YD11CG17(4))
陕西省水务集团水务科技项目(2018SWAG0202)
碑林区科技计划项目(2017KCT-19-01)资助。
关键词
膜
超滤
分子模拟
二级出水
膜污染
membrane
ultrafiltration
molecular simulation
secondary effluent
membrane fouling
