Solubility Characteristics and Crystallization Behavior of Oxalic Acid in the Presence of Sulfuric Acid

Naoko Imura, Izumi Hirasawa

    Research output: Contribution to journalArticle


    Acidic wastewater from industrial discharge is generally treated by neutralization. Before neutralization or water treatment, selective recovery of valuable compounds is necessary to reduce the environmental impact of this acid waste. As a contribution to the development of a novel acidic wastewater treatment, oxalic acid is set as target material which is found in acid waste from the metalworking industry. Crystallization of oxalic acid in the presence of sulfuric acid has rarely been reported. Since this acid waste also contains aluminum ions, the effect of sulfuric acid and aluminum ions on oxalic acid solubility and crystallization was clarified. As a result, sulfuric acid concentration affected the oxalic acid solubility, but aluminum ions had no influence. Oxalic acid was precipitated in columnar shape by cooling crystallization from sulfuric acid aqueous solution with aluminum ions.

    Original languageEnglish
    Pages (from-to)1042-1046
    Number of pages5
    JournalChemical Engineering and Technology
    Issue number6
    Publication statusPublished - 2015 Jun 1



    • Acidic wastewater
    • Aluminum sulfate
    • Cooling crystallization
    • Oxalic acid
    • Solubility
    • Sulfuric acid

    ASJC Scopus subject areas

    • Chemical Engineering(all)
    • Chemistry(all)
    • Industrial and Manufacturing Engineering

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