Water reclamation and microbial community investigation: Treatment of tetramethylammonium hydroxide wastewater through an anaerobic osmotic membrane bioreactor hybrid system

• Published in: Journal of hazardous materials 2022-04, Vol.427, p.128200-128200, Article 128200
• Main Authors: Chang, Hau-Ming, Chen, Shiao-Shing, Hsiao, Shiang-Sheng, Chang, Wen-Shing, Chien, I-Chieh, Duong, Chinh Cong, Nguyen, Thi Xuan Quynh
• Format: Article
• Language: English
• Subjects: Anaerobic osmotic membrane bioreactor; Anaerobiosis; Bioreactors; Membrane distillation; Membranes, Artificial; Microbiota; Microfiltration; Osmosis; Quaternary Ammonium Compounds; RNA, Ribosomal, 16S - genetics; Tetramethylammonium hydroxide; Waste Water; Water; Water Purification
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.128200

Tetramethylammonium hydroxide (TMAH) is a toxic photoresist developer used in the photolithography process in thin-film transistor liquid crystal display (TFT-LCD) production, and it can be removed through anaerobic treatment. TMAH cannot be released into the environment because of its higher toxicity. A tight membrane, such as a forward osmosis (FO) membrane, together with an anaerobic biological process can ensure that no TMAH is released into the environment. Thus, for the first time, an anaerobic osmotic membrane bioreactor (AnOMBR) hybrid system was developed in this study to treat a low-strength TMAH wastewater and to simultaneously investigate its microbial community. Microfiltration extraction was used to mitigate the salinity accumulation, and a periodically physical water cleaning was utilized to mitigate the FO membrane fouling. The diluted draw solute (MgSO4) was reconcentrated and reused by a membrane distillation (MD) process in the AnOMBR to achieve 99.99% TMAH removal in this AnOMBR-MD hybrid system, thereby ensuring that no TMAH is released into the natural environment. Moreover, the membrane fouling in the feed and draw sides were analyzed through the fluorescence excitation-emission matrix (FEEM) spectrophotometry to confirm that the humic acid-like materials were the primary membrane fouling components in this AnOMBR. Additionally, 16S rRNA metagenomics analysis indicated that Methanosaeta was the predominant contributor to methanogenesis and proliferated during the long-term operation. The methane yield was increased from 0.2 to 0.26 L CH4/g COD when the methanogen species acclimatized to the saline system. [Display omitted] ●TMAH removal is achieved 99.99% in this AnOMBR hybrid system.●Humic acid-like materials is the major membrane fouling components in this AnOMBR.●Methanosaeta is the predominant microorganism for this TMAH treatment.●Methanomethylovorans played the major role for TMAH biodegradation.●Methane yield is increased when the microorganism acclimatize to the saline system.