Kim TK, Kim T, Lee I, Choi K, Zoh KD. Removal of tetramethylammonium hydroxide (TMAH) in semiconductor wastewater using the
nano-ozone H
2O
2 process.
J Hazard Mater 2021;
409:123759. [PMID:
33451854 DOI:
10.1016/j.jhazmat.2020.123759]
[Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 06/12/2023]
Abstract
In this study, we used a nano-ozone bubble to enhance the efficiency of the ozone/H2O2 process for the degradation of tetramethylammonium hydroxide (TMAH) found in semiconductor wastewater at high levels. The nano-ozone bubble significantly increased ozone mass transfer rate compared to that of the macro-ozone bubble. The half-life of nano-ozone bubbles was 23 times longer than that of the nano-ozone bubbles. Due to the high ozone mass transfer rate and its durability, the nano-ozone bubble increased the TMAH degradation rate compared to that of the macro-ozone. The addition of H2O2 significantly increased the TMAH degradation rate constant by OH production during the nano-ozone bubbles/H2O2 process. The optimum conditions for TMAH removal was 25 °C and pH 10. Within 90 min of the nano-ozone/H2O2 process, TOC removal was 65 % while 80 % of nitrogen was converted into nitrate (NO3-) with 95 % of TMAM removal. Decreases in acute (40-fold) and chronic (2-fold) toxicity were achieved after applying the nano-ozone/H2O2 process to TMAH containing wastewater. However, there was no significant chronic toxicity decrease during the nano-ozone/H2O2 process of TMAH.
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