title: Denitrification with epsilon-caprolactam by acclimated mixed culture and by pure culture of bacteria isolated from polyacrylonitrile fibre manufactured wastewater treatment system.
abstract: The aim of this study is to isolate denitrifying bacteria utilizing epsilon-caprolactam as the substrate, from a polyacrylonitrile fibre manufactured wastewater treatment system. The aim is also to compare the performance of PAN (polyacrylonitrile) mixed bacteria cultures acclimated to epsilon-caprolactam and isolated pure strain for treating different initial epsilon-caprolactam concentrations from synthetic wastewater under anoxic conditions. The result showed that the PAN mixed bacteria cultures acclimated to epsilon-caprolactam could utilize 1538.5 mg/l of epsilon-caprolactam as a substrate for denitrification. Sufficient time and about 2200 mg/l of nitrate were necessary for the complete epsilon-caprolactam removal. Paracoccus thiophilus was isolated from the polyacrylonitrile fibre manufactured wastewater treatment system and it could utilize 1722.5 mg/l of epsilon-caprolactam as a substrate for denitrification. About 3500 mg/l of nitrate was necessary for the complete removal of epsilon-caprolactam. When the initial epsilon-caprolactam concentration was below 784.3 mg/l, the removal efficiency of epsilon-caprolactam by Paracoccus thiophilus was better than that for the PAN mixed bacteria cultures. The growth of Paracoccus thiophilus was better. However, when the initial epsilon-caprolactam concentration was as high as 1445.8 mg/l, both the epsilon-caprolactam removal efficiency by Paracoccus thiophilus and Paracoccus thiophilus specific growth rate were similar to the PAN mixed bacteria cultures.
authors.affiliation: Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Chinese Taiwan. cmlee@enve.ev.nchu.edu.tw
authors.forename: C M
authors.initials: CM
authors.lastname: Lee
authors.forename: C C
authors.initials: CC
authors.lastname: Wang
mesh_terms: D000180:Acrylic Resins; D001673:Biodegradation, Environmental; D002209:Caprolactam / Q000737:chemistry / Q000378:metabolism*; D002273:Carcinogens; D007220:Industrial Waste; D010230:Paracoccus / Q000254:growth & development / Q000302:isolation & purification* / Q000502:physiology; D011157:Population Dynamics; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D002273:Carcinogens; D007220:Industrial Waste; C010504:polyacrylonitrile; D002209:Caprolactam