Organic matter removal from oil-water emulsions by electrocoagulation - 1: thermodynamic analysis

Rem: Revista Escola de Minas

Rodolfo Maia Rangel²  Roberto José De Carvalho¹  Maurício Leonardo Torem¹ 

[1] ,Pontifícia Universidade Católica do Rio de Janeiro Departamento de Engenharia de Materiais

关键词: Electrocoagulation;    oil-water emulsions;    organic matter (COD);    thermodynamics;    Eletrocoagulação;    emulsões óleo-água;    matéria orgânica (DQO);    termodinâmica;   

DOI  :  10.1590/S0370-44672013000100010

来源: SciELO

【 摘 要 】

A thermodynamic analysis of the organic matter (chemical oxygen demand - COD) removal from synthetic oil-water emulsions by the electrocoagulation process was performed with the objective of determining the most stable ionic species under diverse pH and aluminum concentration conditions and identifying possible removal mechanisms. The analysis suggests that the predominant species during the reactive stage are the amorphous aluminum hydroxide (for the mononuclear speciation of aluminum) and the positively charged trimeric species, Al3(OH)45+ (for the polynuclear speciation of aluminum). The emulsion destabilization probably occurs by charge neutralization, carried out jointly by the polynuclear species and by positively charged aluminum hydroxide. This sorption mechanism is likely to be the primary coagulation mechanism during the reactive stage. The formation of aluminum hydroxide and/or oxide during the stabilization stage may also take place, which indicates the gradual change of the dominant removal mechanism to sweep flocculation.

【 授权许可】

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