以低浓度废酸驱动中和渗析脱盐的模拟与验证  

Modeling neutralization dialysis desalination driven by low concentration waste acid and its validation

作　　者：陈朝光 贾玉香[1] 汪锰[1] CHEN Zhaoguang;JIA Yuxiang;WANG Meng(College of Chemistry and Chemical Engineering,Ocean University of China,Qingdao 266100,Shandong,China)

机构地区：[1]中国海洋大学化学化工学院,山东青岛266100

出　　处：《化工学报》2023年第6期2486-2494,共9页CIESC Journal

基　　金：国家自然科学基金项目(22278385);山东省自然科学基金项目(ZR2020MB116)。

摘　　要：低浓度废酸的资源化长期困扰着相关涉酸工艺。基于Donnan渗析原理,提出以低浓度废酸驱动中和渗析地表水脱盐,借助模拟和实验来探索耦合工艺的可行性。首先,基于Nernst-Planck、Navier-Stokes方程和电中性条件,面向中和渗析过程数学建模,研究废酸浓度对脱盐率、脱盐速度和体系pH等脱盐效果的影响。模拟结果表明,常规低浓度废酸(pH=0.5~2)足以有效驱动中和渗析脱盐过程,且提高酸浓度也未得到明显强化。进而,以均相或异相离子交换膜构建中和渗析膜堆,开展条件实验,获得了系列与模拟结果相吻合的实验规律。实验也表明,对于高浓度废酸,异相膜较显著的同离子泄漏现象会严重劣化脱盐效率。综合研究表明,耦合新工艺有望为低浓度废酸的资源化开辟新途径。The reclamation of low concentration waste acid has long puzzled acid-related technology.Based on the Donnan dialysis principle,a novel technology which couples the waste acid reclamation with neutralization dialysis desalination is put forward in this work.Its feasibility is demonstrated by means of model simulation and experiment validation on the basis of the practical application of surface water desalination driven by a series of waste acid with typical concentrations.Firstly,based on Nernst-Planck equation,Navier-Stokes equation and electroneutral condition,an unsteady mathematical model is established to explore the effects of acid concentration on the desalination rate,desalination speed and pH of system.The simulated results show that the relative low concentration of acid(pH=0.5—2)is strong enough to drive the neutralization dialysis process which is not strengthened remarkably after a further increase of acid concentration.Subsequently,a neutralization dialysis membrane stack is constructed by typical commercial homogeneous or heterogeneous membranes for desalination experiments and provides a series of results which agree well with model predictions.Experiments also show that for high-concentration waste acid,the more significant leakage of the same ion in the heterogeneous membrane will seriously deteriorate the desalination efficiency.The comprehensive research shows that the coupled new process is expected to open up a new way for the resource utilization of low-concentration waste acid.

关 键 词：中和渗析 废物处理 离子交换膜 脱盐 数学模拟 

分 类 号：TQ028.8[化学工程]