Abstract

PRIETO-GARCIA, Francisco et al. Electrodissolution aluminum electrode during an electrocoagulation acid whey. Dyna rev.fac.nac.minas [online]. 2014, vol.81, n.187, pp.129-136. ISSN 0012-7353.  https://doi.org/10.15446/dyna.v81n186.40757.

Electrodissolution of aluminum in solutions containing chloride or sulfate ions during electrocoagulation acid whey, has been the objective of this work. The alkaline pH increases the rate of dissolution by several orders of magnitude. The electrolytic medium (Cl^- or SO₄^2-) does not seem to significantly influence the dissolution of aluminum, but increase the charge density, which helps in the electrochemical process. The results are related to the nature of aluminum hydroxide species formed during anodic dissolution. In acidic and neutral conditions, OH-ions from the cathode do not fully participate in the formation of neutral species of aluminum hydroxide and excess OH-ions increases the pH of the medium. In contrast, the pH decreases in highly alkaline conditions attributed to the consumption of large amounts of OH^- ions to form an anionic species such as Al(OH)₄^- and Al(OH)₅^2-, and other polymeric species of aluminun.

Keywords : electrocoagulation; acid whey; chemical dissolution; electrodissolution; aluminum electodes.

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