论文总字数：26693字

摘 要

膜分离技术能够有效回收有用组分，在处理印染废水领域有良好的应用前景和发展潜力。纳滤膜具有的200~1000Da分子截留范围以及荷负电对离子高选择性两大特点，使其能有效分离含盐染料废水中染料大分子与小分子盐，从而资源化利用。本文对比纳滤膜分离技术与其他常用膜分离技术在印染废水中的应用，介绍纳滤膜的分离机理并总结国内外对纳滤处理染料废水影响因素的相关研究情况。本文目的在于研究具有良好化学稳定性与机械强度的无机陶瓷对含盐染料废水的分离效果。探究跨膜压差，膜面流速，溶液pH纳滤渗透通量和对有机物截留情况，进一步开展不同盐浓度纳滤分离实验，探讨一价盐对有机物截留的影响。

实验表明，跨膜压差对染料截留情况影响显著，两种活性染料渗透通量随跨膜压差增加而增大，甲基橙染料渗透通量偏低；分子量为327g/mol甲基橙拦截率为60%，而分子量为626g/mol活性艳蓝与分子量为991g/mol活性黑拦截率较高，均高于95%。膜面流速对染料渗透通量有一定影响，膜面流速加强流体湍流状态，因此三种染料渗透通量随膜面流速增加而增大，拦截率亦随之增大但之间差异不大。pH对渗透通量和溶质拦截略有影响，中性条件渗透通量最低，酸性条件下拦截率略有下降，且实验进水与出水pH存在差异。

不加盐与盐浓度分别为0.5%，2%，5%，10%的不同染料模拟废水实验，实验结果差异较大。甲基橙模拟染料废水含盐条件下渗透通量均高于不含盐条件下，拦截率随着盐浓度增加而增加，从20%左右升至95%。活性艳蓝模拟染料废水渗透通量随盐浓度增加而降低，高盐条件下渗透通量不随着跨膜压差变化而变化，而拦截率随盐浓度增加先减后增，均低于不含盐条件。活性黑模拟染料废水渗透通量随盐浓度增加而降低，拦截率随盐浓度增加急剧降低，2%盐浓度时拦截率最高只有20%，10%盐浓度则拦截率低于10%。

关键词：纳滤；操作条件；染料截留；氯化钠；

Effect of monovalent salt on organic solutes retention using nanofiltration membranes in wastewater treatment

Abstract

Membrane technologies have high recovery of valuable products, which enables these technologies hold great promise and potential in textile wastewater treatment. Nanofiltration(NF), with low molecular weight cut-off(MWCO) ranging from 200 to 1000Da and high ion selective ability due to its negative surface, is able to separate the effluent into a reject stream containing the dyestuff while allowing water and NaCl to pass through at the permeate stream, which obtain the goal of recycling useful resources. This paper compares NF with other commonly used membrane technologies in textile wastewater treatment, introduces NF separation theories and summarizes worldwide researches about influencing factors on wastewater treatment using nanofiltration in literature review. This paper aims to carry on experiments on wastewater containing dye/salt mixtures using ceramic nanofiltration membrane which presents several advantages as extreme chemical and mechanical resistance. This paper focuses on effects of operating parameters including trans-membrane pressure (TMP), cross flow velocity (CFV) and pH on the retention of organic solutes. This paper emphasizes the effect of salt concentration on the membrane performance to analyze NaCl influence on the retention of organic solutes.

Experimental results showed that the effect of TMP on dye retention was apparent. Two reactive dyes, Reactive Blue 19 (KNR) and Reactive Black 5 (RB5), both permeate fluxes increased with an increase in operating pressure, while Methyl Orange (MO) permeate flux was lowest; the retention of MO( molecular weight of 327g/mol) was 60%, while retention rates of KNR, RB5( molecular weight of 626,991g/mol) were above 95%. CFV had positive effect on dye retention by increasing flow turbulent condition, which contributed to three kinds of dye permeate fluxes and retention rates up slightly with faster CFV. pH had insignificant effects on the rejection of dye. Under neutral condition, permeate fluxes was lowest; under acid condition, dye retention rates dropped slightly. In addition, pH values of permeate stream and feed stream were different by testing after each pH experiment.

Experimental results of dye/NaCl mixtures wastewater treatment using nanofiltration were different. The presence of NaCl rose up the permeate flux of MO, while with increasing NaCl

concentrations MO retention rates changed from 20% to 95%. Permeate fluxes of KNR declined with increasing NaCl concentrations and permeate fluxes were independent of TMP under high NaCl concentrations. When NaCl ranges from 0.5 to 10%, retention rates decreased at first then increased to the amount less than the retention rate of KNR without NaCl. RB5 permeate fluxes and retention rates declined with increasing NaCl concentrations and the decline of retention rates was sharp meaning that retention rated was 20%with 2%NaCl and below 10%with 10%NaCl.

Keywords：nanofiltration; operating parameters; dye retention; NaCl;

目录

摘要……...……………………………………………………………………………………………....…….I

Abstract...............................................................................................................................................................II

第一章 引言 1

1.1研究背景 1

1.2纳滤膜分离技术 2

1.2.1纳滤膜与其他膜分离技术对比 2

1.2.2纳滤膜材料分类与分离机理 3

1.2.3纳滤截效果优化影响因素 3

1.3课题目的、内容及研究意义 6

第二章 实验部分 7

2.1实验试剂及仪器 7

2.1.1药品 7

2.1.2仪器 7

2.2实验材料特性 7

2.2.1染料性质分析与标准曲线确定 7

2.2.2纳滤膜管 9

2.3实验装置 10

2.4实验方法 10

2.4.1实验准备 10

2.4.2条件影响实验 11

2.5实验表征与测试方法 11

2.5.1纯水通量 11

2.5.2渗透通量 11

2.5.3截留率 11

第三章 操作条件对有机物截留影响 12

3.1跨膜压差的影响 12

3.2膜面流速影响 14

3.3 pH影响 17

3.3.1 pH-染料溶质关系 19

3.3.2 pH-膜管关系 19

第四章 一价盐对有机物截留影响 20

4.1甲基橙 20

4.2活性艳蓝 21

4.3活性黑 22

4.4无机盐离子对染料截留影响机理分析 23

4.4.1渗透压 25

4.4.2盐离子对染料聚集态的影响 25

4.4.3盐离子与膜管相互作用影响 26

第五章 结论与展望 26

5.1结论 26

5.2展望 27

参考文献 28

致谢................................................................................................................................................................... 32

第一章 引言

1.1研究背景

含盐含有机物的废水来源广泛，包括化工，制药，农药，印染等多种行业。其中印染行业产生废水约占整个工业废水的三分之一^[[1]]，其水量大，有机污染物量大，色度深，含盐量高（NaCl~6.0wt%，Na₂SO₄~5.6wt%^[[2]]）等特点增加废水处理难度。在当前能源危机和资源短缺的形势下，如何对印染废水进行深度处理，节能高效地回收利用其中可资源化成分，是目前水处理与资源化利用的热点与难点。

目前，国内外对于含盐印染废水常用的处理工艺主要是生物法，物化法。

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