Recovery of Inorganic Waste Sulfuric Acid by Membrane Separation: A Concise Review

Inorganic waste sulfuric acid containing heavy metal ions is difficult to treat and has low recycling efficiency, resulting in great harm to the water, soil, and human living environments. In this paper, research of membrane separation technology to recover sulfuric acid is reviewed and analyzed, and its development direction prospected. The analysis shows that membrane contamination restricts the application of membrane distillation. Diffusion dialysis has the advantages of low energy consumption and high purity of sulfuric acid recovery, but the recovery speed is slow and time-consuming. Electrodialysis has the advantages of high sulfuric acid recovery and short process, but it has some problems such as high energy consumption and H⁺ leakage. The combined process of vacuum film distillation and mechanical steam recompression can greatly improve the utilization rate of latent heat. The coupling process, in which electrodialysis or diffusion dialysis and membrane distillation are performed after the waste sulfuric acid has been pretreated with ceramic membrane, is an important way to effectively solve the existing problems. According to the characteristics of impurities in inorganic waste sulfuric acid, it is an important direction for efficient and comprehensive utilization to produce corresponding sulfate products.