Application of ozone related processes to mineralize tetramethyl ammonium hydroxide in aqueous solution

Chyow San Chiou, Kai Jen Chuang, Ya Fen Lin, Hua Wei Chen, Chih Ming Ma

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7 Citations (Scopus)


Tetramethyl ammonium hydroxide (TMAH) is an anisotropic etchant used in the wet etching process of the semiconductor industry and is hard to degrade by biotreatments when it exists in wastewater. This study evaluated the performance of a system combined with ultraviolet, magnetic catalyst (SiO 2/Fe3O4) and O3, denoted as UV/O3, to TMAH in an aqueous solution. The mineralization efficiency of TMAH under various conditions follows the sequence: UV/O3 > UV/H2O2/O3 > H2O 2/SiO2/Fe3O4/O3 > H2O2/O3 > SiO2/Fe 3O4/O3 > O3 > UV/H 2O2. The results suggest that UV/O3 process provides the best condition for the mineralization of TMAH (40 mg/L), resulting in 87.6% mineralization, at 60 min reaction time. Furthermore, the mineralization efficiency of SiO2/Fe3O4/H 2O2/O3 was significantly higher than that of O3, H2O2/O3, and UV/H 2O2. More than 90% of the magnetic catalyst was recovered and easily redispersed in a solution for reuse.

Original languageEnglish
Article number191742
JournalInternational Journal of Photoenergy
Publication statusPublished - 2013


ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Chemistry(all)
  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)

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