title: A combined upflow anaerobic sludge bed, aerobic, and anoxic fixed-bed reactor system for removing tetramethylammonium hydroxide and nitrogen from light-emitting diode wastewater.
abstract: A laboratory study using a combined upflow anaerobic sludge bed (UASB) and aerobic and anoxic fixed-bed reactor system was undertaken to explore its capability for removing tetramethylammonium hydroxide (TMAH) and nitrogen from light-emitting diode wastewater. When the organic loading rate was maintained at 0.26-0.65 kg TMAH m(-3 )d(-1), the UASB reactor removed 70-100% of TMAH through methanogenesis. When the [Formula: see text] -N loading rate was maintained at 0.73-1.4 kg [Formula: see text]-N m(-3 )d(-1), the aerobic reactor oxidized 31-59% of [Formula: see text]-N to [Formula: see text]-N through nitritation. When the nitrogen loading rate was maintained at 0.42-0.75 kg N m(-3 )d(-1), the anoxic reactor removed 27-63% of nitrogen through anammox. The performance data of the combined reactor system agreed well with the stoichiometric relationships of methanogenesis, nitritation, and anammox. The batch studies showed that a higher initial TMAH concentration of up to 2520 mg L(-1) gave a higher methanogenic activity of up to 16 mL CH4 g(-1) VSS d(-1). An increase in the initial TMAH concentration of up to 500 mg L(-1) gradually decreased the activity of ammonia-oxidizing bacteria; whereas an increase in the initial TMAH concentration of up to 47 mg L(-1) imposed a marked inhibiting effect on the activity of anammox bacteria.
authors.affiliation: a Department of Environmental Engineering , National Cheng Kung University , Tainan , Taiwan.
authors.forename: Han-Lin
authors.initials: HL
authors.lastname: Lin
authors.affiliation: b Department of Environmental Engineering , Kun Shan University , Tainan , Taiwan.
authors.forename: Sheng-Kun
authors.initials: SK
authors.lastname: Chen
authors.affiliation: a Department of Environmental Engineering , National Cheng Kung University , Tainan , Taiwan.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Huang
authors.affiliation: b Department of Environmental Engineering , Kun Shan University , Tainan , Taiwan.
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Chen
authors.affiliation: c Sun Chi Environmental Inc. , Taichung , Taiwan.
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Chien
authors.affiliation: a Department of Environmental Engineering , National Cheng Kung University , Tainan , Taiwan.
authors.forename: Sheng-Shung
authors.initials: SS
authors.lastname: Cheng
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D006878:Hydroxides / Q000302:isolation & purification* / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification* / Q000378:metabolism; D012722:Sewage / Q000032:analysis*; D014865:Waste Disposal, Fluid / Q000295:instrumentation*; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000302:isolation & purification* / Q000378:metabolism; D018508:Water Purification / Q000295:instrumentation
chemical_list: D006878:Hydroxides; D009584:Nitrogen; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical; C027917:tetramethylammonium
keywords: Anammox; TMAH; methanogenesis; nitritation; nitrogen removal