摘要
通过特定化学反应对截留相对分子质量30×10^3再生纤维素(RC)膜进行表面修饰,得到3种氨基酸(甘氨酸、丝氨酸和赖氨酸)改性的两性离子超滤膜,选取3种分子量相近而所带电荷量不同的染料分子(亚甲基蓝、甲基橙和直接黄12),以考察两性离子超滤膜回收水中染料分子的可能。研究比较了染料荷电量、膜的接枝基团及离子强度对以上3种染料截留率的影响。结果表明,相较于中性膜,两性膜仅对荷负电染料截留能力增强;赖氨酸改性膜尽管荷电性呈中性,但仍有与其他改性膜相近的去除效果,在膜通量约为50 L/(m^2·h)时,对直接黄12的截留率可达80%左右,这归因于赖氨酸基团形成了更致密的水化层;此外,离子强度的增加屏蔽了膜与荷负电染料的静电排斥,最终导致截留率降低。
Three different amino acid ligands(glycine, serine and lysine) modified zwitterionic ultrafiltration membranes were prepared by surface modification of relative molecular mass of 30×10^3 regenerated cellulose membranes with specific chemical reaction. Three model dyes(methylene blue,methyl orange and direct yellow 12) with similar molecular weights but different charge density were selected, to research the possibility of dyes molecule recycled by zwitterionic ultrafiltration membrane. The effects of charge density of the dye molecules, grafted groups of membranes and ionic strength on rejection rate of three dyes were studied. Results indicated that, all the zwitterionic membranes had better removal rate for negatively charged dyes compared to neutral membrane. Lysine modified membrane had comparable removal rate with other modified membranes although its zeta potential was close to neutral. The rejection rate of direct yellow 12 could reach 80% at a water flux of 50 L/(m^2·h), which was caused by its denser hydration layer from lysine molecule. Besides, the increase of ionic strength would reduce the electrostatic interactions between membranes and dye molecules, thus reducing the rejection coefficient of dyes.
作者
苏晨
迟莉娜
邵嘉慧
SU Chen;CHI Lina;SHAO Jiahui(School of Environmental Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《水处理技术》
CAS
CSCD
北大核心
2019年第11期85-89,共5页
Technology of Water Treatment
基金
国家自然科学基金项目（21737002）
国家重点科技项目水专项（2017ZX07202)
关键词
两性离子超滤膜
氨基酸
染料
去除率
zwitterionic ultrafiltration membranes
amino acids
dyes
removal rate
