Demonstration of acid and water recovery systems: Applicability and operational challenges in Indian metal finishing SMEs

Experimental investigation and modeling of diffusion dialysis for HCl recovery from waste pickling solution

“…by membrane technologies), or by regenerating the acid (e.g. by pyrohydrolysis, where also the reacted acid is recovered) (Balakrishnan et al, 2018). Several authors investigated the regeneration of pickling waste acid solutions by spray roasting (Bascone et al, 2016;Regel-Rosocka, 2010).…”

An integrated approach for the HCl and metals recovery from waste pickling solutions: pilot plant and design operations

“…Extended scientific research, in more than 40 years of studies and applications on this topic, has focused mainly on the treatment of the pickling waste at the end of its life. Although several alternative methods of recovering exhausted solutions have been proposed, few applications of demonstrator plants are reported in the literature (Balakrishnan et al, 2018). Balakrishnan et al investigated three different technologies at the demonstrator scale: diffusion dialysis, acid retardation and nanofiltration.…”

“…The acid diffuses across the membrane into the deionised water, whereas metals are blocked by the anion exchange membrane (AEM) due to their positive charge (Strathmann, 2004). Plenty of studies are available in literature for the single DD unit application as pickling waste treatment process (Balakrishnan et al, 2018;Kobuchi et al, 1986;Tongwen and Weihua, 2003). Research efforts have been committed to investigate how the acid recovery efficiency is influenced by the common metals components (Jung Oh et al, 2000;Luo et al, 2013) (e.g.…”