A review of the existing and emerging technologies for wastewaters containing tetramethyl ammonium hydroxide (TMAH) and waste management systems in micro-chip microelectronic industries

• Published in: Chemosphere (Oxford) 2022-11, Vol.307, p.135913-135913, Article 135913
• Main Authors: Innocenzi, Valentina, Zueva, Svetlana B., Ippolito, Nicolò Maria, Ferella, Francesco, Prisciandaro, Marina, Vegliò, Francesco
• Format: Article
• Language: English
• Subjects: Degradation; Hazardous waste; Industrial wastewater; Micro-chop microelectronic industries; Recovery; Tetramethylammonium hydroxide (TMAH); Treatment process
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.135913

The present work aims to describe and review the available technologies and the recent advancements in treating industrial wastewater containing tetramethylammonium hydroxide (TMAH). It is a quaternary ammonium salt and widely used in the microelectronics industry; this kind of company produces large quantities of wastewater containing TMAH. The exhausted solutions must be treated appropriately since TMAH is corrosive, toxic to human health, and ecotoxic. Regarding the concentration at discharge, currently there are no European regulations. Still, it has been indicated that the substance has a negative influence on the oxygen balance and cause eutrophication, and fall into the relevant categories. In the first part of the work, the available technologies and the recent advancements for the treatment of TMAH contained in industrial wastewater are reviewed. Separation methods as such adsorption, ion exchange, membrane processes, and destruction technologies classified as advanced oxidation processes and biological processes have been considered. In the second part of the manuscript, industrial patented wastewater treatments have been described. Biological processes are those more used, being more economically feasible, require very long times not always sustainable. [Display omitted] •Waste management systems in microelectronic industries.•Tetramethylammonium hydroxide (TMAH) contained in the wastewater.•Review of the existing technologies for TMAH wastewaters treatment.•Review of the emerging technologies for TMAH wastewaters treatment.•Comparison of Separation and Destruction technologies.