摘 要

脱钾滤液是制浆废水处理中较为下游的产品，它是碱回收装置产生的飞灰加水溶解，再经过过滤，而后脱钾形成的滤液。它具有盐含量高的特点，其中绝大多数是硫酸根离子，包括少量的氯离子。目前处理脱钾滤液的方法主要有热分盐法和纳滤膜分盐法两大类。但是，这两类方法都有都有一些不足之处。热分盐法工艺简单，但是分离效率低，获得的盐无法达到工业级水平。纳滤分盐法分离纯度高，但是在高盐体系中，需要供给较大的压力，能耗大；此外，纳滤膜表面容易发生结晶现象，破坏膜的结构。

本研究采用常规电渗析的方法脱出脱钾滤液中的氯离子，达到氯离子和硫酸根分离的目的，回收高品质的硫酸盐。研究采用间歇模式，考察了操作电压和初始进料体积比对于氯离子和硫酸根分离效果的影响。结果表明：操作电压越高，氯离子的脱出速率越快，但是氯离子和硫酸根的分离效率越低，研究以回收高纯度的硫酸盐为目的，因此，在较低的操作电压（8 V）最优。初始进料体积比对分离效率几乎没有影响，但是减少新鲜水的用量是有利的，因此，选择大进料比1:0.4进料。在最优条件下，120 min停止实验，淡化液的硫酸根浓度为112468 mg/L，SO₄^2-/Cl^-（摩尔比）为126，可以得到高纯度的硫酸盐。

关键字：电渗析 脱钾滤液 氯离子 硫酸根 分离效率

Application of Electrodialysis for Resource Treatment of Dekalization Filtrate

ABSTRACT

The depot potassium filtrate is a relatively downstream product in the pulping wastewater treatment. It is the filtrate produced by adding water to the fly ash produced by the alkali recovery unit, and then filtered and then depotted. It is characterized by high salt content, most of which are sulfate ions, including a small amount of chloride ions. At present, there are two major methods for the treatment of depotassium-containing filtrates, hot salt separation and nanofiltration membrane salt separation. However, both of these methods have some deficiencies. The hot salt separation process is simple but the separation efficiency is low and the obtained salt cannot reach the industrial level. The nanofiltration salt separation method has a high purity, but in a high salt system, it requires a large pressure and consumes a large amount of energy. In addition, the surface of the nanofiltration membrane is prone to crystallization and destroys the membrane structure.

In this study, conventional electrodialysis was used to dechlorinate the dechlorinated filtrate to achieve the purpose of separation of chloride ion and sulfate and recover high-quality sulfate. The intermittent mode was used to investigate the effect of operating voltage and initial feed volume ratio on the separation of chloride and sulfate. The results showed that the higher the operating voltage, the faster the rate of chloride ion removal, but the lower the separation efficiency of chloride ion and sulfate, the study aimed at the recovery of high-purity sulfate, therefore, at a lower operating voltage (8 V ) Optimal. The initial feed volume ratio has little effect on the separation efficiency, but it is advantageous to reduce the amount of fresh water, so a large feed ratio of 1:0.4 feed was chosen. Under optimal conditions, the experiment was stopped 120 min later. The sulfate concentration of the desalting solution was 112468 mg/L, and the SO₄^2-/Cl^- (molar ratio) was 126, and high-purity sulfate was obtained.

Keywords: Electrodialysis; Dekalization filtrate; Chloride; Sulfate; Separation efficiency

目 录

摘 要 I

ABSTRACT II

目 录 i

第一章 文献综述 1

1.1 研究背景 1

1.1.1 造纸行业状况 1

1.1.2 制浆废水的主要来源 1

1.1.3 脱钾滤液的来源 1

1.1.4 脱钾滤液的处理方法 1

1.2 电渗析技术 2

1.2.1 膜分离技术概述 2

1.2.2 电渗析的原理 3

1.2.3 电渗析器装置 4

1.2.4 电渗析的应用 5

1.2.5 电渗析中膜污染问题 7

1.3 课程研究的目的 8

第二章 实验部分 9

2.1 实验仪器装置与材料 9

2.1.1 测试仪器 9

2.1.2 所用试剂 9

2.1.3 脱钾滤液 9

2.1.4 电渗析装置 9

2.2 检测方法 10

2.2.1 电导率检测 10

2.2.2 无机盐离子（阴离子） 10

2.3 脱盐率与能耗计算 10

2.3.1 脱盐率 10

2.3.2 能耗 11

第三章 实验结果与讨论 12

3.1 操作电压的影响 12

3.1.1 操作电压对离子浓度的影响 12

3.1.2 操作电压对离子摩尔比的影响 13

3.1.3 操作电压对电阻和能耗的影响 13

3.2 进料体积比的影响 13

3.2.1进料体积比对离子浓度的影响 14

3.2.2进料体积比对离子摩尔比的影响 14

3.2.3 进料体积比对电阻和能耗的影响 14

第四章 总结 16

参考文献 17

致谢 20

1. 文献综述

1.1 研究背景

1.1.1 造纸行业状况

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