Wet Process Phosphoric Acid Purification Using Functionalized Organic Nanofiltration Membrane

Separations

article

Khaoula Khaless¹  Hamza Chanouri¹  Said Amal¹  Abla Ouaattou³  El Mahdi Mounir³  Hicham Haddar³  Rachid Benhida¹ 

[1] Chemical and Biochemical Sciences, Green Process Engineering ,(CBS.GPE), Mohammed VI Polytechnic University;Institut de Chimie de Nice ,(ICN), UMR CNRS 7272, Université Côte d’Azur;Situation Innovation OCP SA

关键词: nanofiltration;    phosphoric acid;    membrane;    functionalization;    purification;    pilot scale;   

DOI  :  10.3390/separations9040100

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

The utilization of phosphoric acid in various sectors, e.g., food industry, is controlled by the authorized concentration limit of impurities. However, industrial phosphoric acid is contaminated with undesirable impurities (such as F, Al, Fe, Mg, etc.). Herein, this study aimed to evaluate the efficiency of the membrane purification process of pretreated industrial phosphoric acid using a premodified nanofiltration membrane. We demonstrated that the prior pretreatment steps for industrial phosphoric acid allowed the elimination of sulfate, fluorine and arsenic. Further purification of the obtained pretreated phosphoric acid using membrane cells reduced the concentrations of Cd, Al, Fe and rare earth elements by 94.81, 99.30, 99.63 and 96.67%, respectively. The membrane is functionalized by a deposit of a high molecular weight polycationic polymer of polyethyleneimines in order to produce a highly charged membrane surface to enhance the separation efficiency, selectivity and stability of the membrane. We found that the purification process relies on electrostatic repulsion between the functionalized membrane and highly charged ions, and the reduction rate of metals is a cation charge-dependent parameter. The laboratory and industrial pilot scale results showed that this process allows the production of food-grade phosphoric acid.

【 授权许可】

CC BY