离子对纳滤去除布洛芬的影响及聚酰胺纳滤膜耐氯性能分析

发布时间：2018-01-29 04:53

本文关键词： 布洛芬聚酰胺膜通量截留率耐氯性　出处：《沈阳师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：水环境中的PPCPs微量有机污染物危害着人类健康并且对生态系统的稳定性造成了潜在的威胁。鉴于其难以被微生物降解和污染的持久性,生物体的内分泌系统会被其持续性干扰。本文选取了典型常见的PPCPs污染物布洛芬为例,主要考察纳滤膜的吸附作用和溶液中离子种类、离子强度对纳滤膜去除微量有机污染物布洛芬的效果产生的影响。在水处理过程中,纳滤膜容易受到水中活性氯的攻击导致膜性能下降,本文采用活性氯浸泡法,即配制不同浓度并且不同p H值的活性氯溶液,在一定时间内浸泡聚酰胺纳滤膜,并通过膜通量、截留率、ATR-FTIR以及SEM四个方面来表征浸泡前与浸泡后聚酰胺纳滤膜的基本性能,得到以下结论:(1)随着过滤过程进行,膜面出现吸附现象直至稳定状态,去除率38%,;膜通量由0.01995L/m2s增大至0.02028L/m2s后趋于稳定。在探究膜对于IBU释放能力过程中,大约有吸附量90%的IBU被洗脱下来,其余则残留于膜孔中,堵塞膜孔进而使膜污染。(2)溶液中存在的Ca Cl2可以提高IBU去除率。纳滤膜对于IBU的去除率受阳离子的电荷数影响比较大,电荷数越多,压缩膜面双电层强度越大,使膜孔变小,一方面使膜通量降低,另一方面使膜更容易截留IBU分子,因此,溶液中的Ca2+对于纳滤去除IBU的影响比Na+大;SO带两个单位负电荷,与膜面的静电斥力强于Cl-,造成膜通量和对于IBU的截留率均降低。(3)浸泡液有效浓度一定时,酸性条件下,纳滤膜截留性能显著下降;中性条件时膜性能受影响的程度低于酸性条件,因为该条件下聚酰胺氯化程度低;碱性时聚酰胺不发生氯化反应或氯化程度非常小。膜面组分通过ATR-FTIR测试,膜面结构通过SEM扫描,得出结果与膜性能下降的原因十分相符。
[Abstract]:Trace organic pollutants of PPCPs in water environment are harmful to human health and pose a potential threat to the stability of ecosystems. The endocrine system of organism will be disturbed by it. The typical PPCPs pollutant ibuprofen is selected as an example to investigate the adsorption of nanofiltration membrane and ion species in solution. Effect of ion strength on removal of trace organic pollutant ibuprofen by nanofiltration membrane. In the process of water treatment, nanofiltration membrane is vulnerable to the attack of active chlorine in water, which leads to the degradation of membrane performance. In this paper, the active chlorine immersion method was used, that is, the active chlorine solution with different concentration and pH value was prepared, and the polyamide nanofiltration membrane was soaked in a certain time, and the membrane flux and rejection rate were obtained. ATR-FTIR and SEM were used to characterize the basic properties of polyamide nanofiltration membrane before and after immersion. Adsorption appeared on the membrane surface until the stable state, and the removal rate was 38%. The membrane flux increased from 0.01995 L / m 2 s to 0.020 28 L / m 2 s, and then became stable. About 90% IBU was eluted and the rest remained in the membrane pore. The removal rate of IBU can be improved by blocking the membrane pore and causing membrane fouling. The removal rate of IBU by nanofiltration membrane is greatly affected by the charge number of cationic ions, and the more the charge number is, the higher the removal rate of IBU is. The larger the strength of the double layer on the compressed membrane surface, the smaller the membrane pore, on the one hand, the decrease of membrane flux, and on the other hand, it is easier for the membrane to intercept the IBU molecule. The effect of Ca2 in solution on IBU removal by nanofiltration is greater than that by Na. The electrostatic repulsion of so with two units of negative charge is stronger than that of Cl-surface, which results in the decrease of membrane flux and retention rate of IBU. 3) when the effective concentration of soaking solution is fixed, the acid condition is obtained. The retention performance of nanofiltration membrane decreased significantly. The effect of neutral conditions on membrane properties was lower than that on acidic conditions because of the low chlorination of polyamides; The chlorination reaction or chlorination degree is very small in alkaline polyamide. The membrane surface component is tested by ATR-FTIR and the membrane surface structure is scanned by SEM. The results are in good agreement with the reason of the degradation of membrane properties.
【学位授予单位】：沈阳师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;TQ051.893

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