Adsorption of Tetramethylammonium Hydroxide on Activated Carbon

Abstract

Tetramethylammonium hydroxide (TMAH) is widely used in manufacturing thin-film transistor liquid crystal displays (TFT-LCD) and semiconductors. Because of its toxicity and nitrogen content, TMAH-containing wastewater has to be properly treated before discharge. In this study, several commercial activated carbons were characterized and used for TMAH adsorption. Activated carbon with micropores showed higher adsorption capacity for TMAH. The adsorption kinetics could be represented by pseudo-second-order model, and the Langmuir model fitted the adsorption of TMAH on activated carbon under different pH adsorption well. Higher pH was favorable for TMAH adsorption, while there was no TMAH adsorption at pH 4:7 AE 0:2. The adsorption was spontaneous and exothermic. Exhausted carbon could be easily regenerated by 0.1 N HCl, with no considerable reduction in performance even after five cycles of adsorptiondesorption. It was proposed that electrostatic interaction was the main mechanism of TMAH adsorption on the activated carbon.

Adsorption Isotherm Study for the Removal of Nickel Ions From Aqueous Solution Using Thermal Power Plant Fly Ash

“…The amount of metallic ion adsorbed by the fly ash (mg/g) was calculated using the following equation (Devarly et al, 2012).…”

Efficient adsorptive removal of Tetramethylammonium hydroxide (TMAH) from water using graphene oxide

“…A few studies had indicated that the adsorption process is a feasible technique to remove TMAH from water [8,9] using a mesoporous silicate and commercial activated carbons as adsorbents. However, the adsorbents were not particularly functionalized with task-specific functional groups (e.g., acidic sites) to enhance the adsorption of highly basic TMAH.…”

Assessment of an MnCe-GAC Treatment Process for Tetramethylammonium-Contaminated Wastewater from Optoelectronic Industries

“…High concentrations of TMAH solutions from factories could be physicochemically recovered and recycled, while wastewater containing lower concentrations of TMAH (in the order of hundreds of mg/L) can be treated in wastewater treatment facilities [9,12]. Common treatment processes for nitrogen-containing wastewater include adsorption [13][14][15], biological processes [9,11], ozonation [16], chemical oxidation [17], electrodialysis [18], and UV/persulfate [19,20]. Although wastewater containing high concentrations of TMAH can be treated by Fenton oxidation and catalytic oxidation processes, costs of these processes can be very high [11].…”