title: Combined photocatalysis and membrane bioreactor for the treatment of feedwater containing thin film transistor-liquid crystal display discharge.
abstract: The nitrogen content of waste water generated by the thin film transistor-liquid crystal display (TFT-LCD) industry is not satisfactorily removed through the conventional aerobic-activated sludge process. In this study, the performance of three reactors – suspended type TiO2 membrane photoreactor (MPR), anoxic/oxic membrane bioreactor (AOMBR), and their combination (MPR-AOMBR) – was evaluated using feedwater containing TFT-LCD discharge. The parameters that maximized monoethanolamine (MEA) removal in the MPR were continuous ultraviolet (UV) irradiation and pH 11. Among the tested loadings, 0.1 g/l of TiO2 promoted MEA removal but degradation rate may further increase with photocatalyst concentration. The nitrified sludge recycle ratio R of the AOMBR was adjusted to 1.5 to minimize the amount of nitrate in the effluent. The AOMBR greatly decreased chemical oxygen demand and MEA, but removed only 32.7% of tetramethyl ammonium hydroxide (TMAH). The MPR was configured as the pre-treatment unit for AOMBR, and the combined MPR-AOMBR has improved TMAH removal by 80.1%. The MPR bolstered performance by decomposing slowly biodegradable compounds, and had no negative effects on denitrification and carbon removal.
authors.affiliation: a Department of Bioenvironmental Engineering and R&D Center for Membrane Technology , Chung Yuan Christian University , 200 Chung Pei Road, Chungli 32023 , Taiwan.
authors.forename: Sheng-Jie
authors.initials: SJ
authors.lastname: You
authors.affiliation: a Department of Bioenvironmental Engineering and R&D Center for Membrane Technology , Chung Yuan Christian University , 200 Chung Pei Road, Chungli 32023 , Taiwan.
authors.forename: Galilee Uy
authors.initials: GU
authors.lastname: Semblante
authors.affiliation: a Department of Bioenvironmental Engineering and R&D Center for Membrane Technology , Chung Yuan Christian University , 200 Chung Pei Road, Chungli 32023 , Taiwan.
authors.forename: Yu-Pu
authors.initials: YP
authors.lastname: Chen
authors.affiliation: b Institute of Environmental Planning and Management , National Taipei University of Technology , Taipei , Taiwan.
authors.forename: Tien-Chin
authors.initials: TC
authors.lastname: Chang
mesh_terms: D019856:Ethanolamine / Q000737:chemistry / Q000302:isolation & purification; D008567:Membranes, Artificial; D058433:Photobioreactors; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000302:isolation & purification; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical; D019856:Ethanolamine; C027917:tetramethylammonium
keywords: membrane photoreactor (MPR); monoethanolamine (MEA); sludge recycle ratio; tetramethyl ammonium hydroxide (TMAH)