【作者】 张岩；

【导师】 黄中华；

【作者基本信息】 南京理工大学 ， 环境工程， 2016， 硕士

【摘要】 本文选用卡马西平(CBZ)、布洛芬(IBU)、磺胺甲恶唑(SMZ)和阿替洛尔(ATE)四种药物及个人护理品(PPCPs),探讨了PPCPs在以聚醚砜超滤膜(PES)为支撑层、2-羟丙基三甲基氯化铵壳聚糖(HTCC)为活性层的荷电膜上分离的影响因素。采用不同浓度的天然有机物(NOM)溶液,进行纳滤截留PPCPs实验,探究NOM对纳滤截留率的影响以及NOM污染后纳滤膜通量的变化。分析了相对分子质量范围在30～700之间的26中有机物的纳滤截留率大小与分子质量、分子斯托克斯直径、等效摩尔直径、能量最小化计算直径、分子极性和荷电性的关系。利用细孔模型(SHP)和道南-空间位阻模型(DSPM),研究纳滤截留规律,建立了纳滤截留电解质溶液的理论模型。NOM对四种PPCPs的影响主要有三类：1.膜污染导致膜孔变小,截留率上升；2.NOM与PPCPs的亲疏水性,使两者之间发生相互作用,同性分子相互吸引使膜面PPCPs浓度升高,浓差极化作用导致截留率降低,异性分子相互排斥,PPCPs分子不易从主体溶液向膜面扩散导致截留率升高；3.NOM分子与PPCPs分子键合,体积增大从而不易通过膜孔,提高截留率。选取分子量不同的26种有机物进行截留实验,采用TOC、紫外-可见分光光度法测量溶质浓度。结果显示,分子量与截留率相关性为0.734。将分子量按0～100、100～200、200～400、400～700分类后,取各范围分子量和截留率平均值求得相关性为0.9986。截留率与斯托克斯直径、等效摩尔直径和能量最小化计算直径的相关性分别为：0.5316、0.2669、0.5663。截留率与分子极性的相关性为-0.7825,呈现出良好的负相关性。同时选用部分荷电分子,对比中性分子发现,分子量相近的分子,荷正电分子去除率高于中性分子,中性分子的去除率高于荷负电分子。利用细孔模型对HTCC/PES膜的结构表征,以葡萄糖溶液和蔗糖溶液为实验体系,计算出膜的孔径rp为1.04nm,孔积率与膜厚之比Ak/△X为4221 m-1。选用DSPM模型,基于荷正电纳滤膜中荷正电离子浓度显著低于荷负电离子浓度的假设,对DSMP模型进行简化并给出详细推导过程。选用NaCl溶液为研究对象简化了DSPM模型,并用简化的DSPM模型估算了HTCC/PES膜的荷电密度X。更多还原

【Abstract】 This paper selects four kinds of pharmaceutical and personal care products (PPCPs) including Carbamazepine, Ibuprofen, Sulfamethoxazole and Atenolol. Discussed the separation effect of PPCPs with charged membrane synthesized by polyethersuifone (PES) ultraflitration membrane as the support layer and 2-hydroxypropyl trimethyl ammonium chloride chitosan (HTCC) as the active layer. Two kinds of natural organic matter (NOM) were choosen for the permeation experiment to explore the impact of NOM on PPCPs rejection. We also selected 26 kinds of organics for studying the influence of molecular size, polarity and charge on the retention of organic molecues by nanofiltration. Finally steric-hindrance pore (SHP) model and Donnan steric partitioning pore (DSPM) model were established by filtration experience of aqueous solutions of sodium chloride in order to characterization and prediction the separation performance of HTCC/PES membrane.The experimental results showed that NOM used in the study displayed obviously diverse impacts on PPCPs removal and flux decline by HTCC/PES membrane. These impacts seemed to correlate with followed three points:1. The formation of the filter cake layer could alter molecular weight cut-off,2. The hydrophobicity or hydrophilic of NOM and PPCPs.3. The hydrogen bonding interaction. The effect mechanisms have important significance to improve the nanofiltration membrane performance.In this paper, the retention of a series of organic molecules by HTCC/PES nanofiltration membranes was studied. In order to correlate the retention with the size of the molecule, which is the main factor that determines the retention, ues was made of different parameters for the molecular size:molecular weight, the Stokes diameter, the equivalent molar diameter, and a diameter obtained with energy minimization calculations. For each size parameter, the correlation with retention in nanofiltration experiments was calculated. A good correlation was found for molecular weight with the rejection rate. Two other factors were found to have an influence on retention of organic molecules:the polarity of the molecule, and the charge of the molecule.This paper carries on the taken of structure of the HTCC/PES films and the pore path rp of the film is 1.04 nm, the rate of porosity of the membrane and effective membrane thickness is 4221 m-1. Aim at solving the complexity of DSPM model calculation, this essay carries on a simplification of DSPM model and deduce process in details, which bases on the assumption of positive ionic density is greatly lower than the anti-ionic in attached positive nanofiltration film. NaCl electrolyte aqucous was choosen to carry on the experiment, and DSPM model was taking to calculate the nanofiltration film effective membrane volume charge.更多还原