title: Nitric oxide removal by wastewater bacteria in a biotrickling filter.
abstract: Nitric oxide (NO) is one of the most important air pollutants in atmosphere mainly emitted from combustion source. A biotrickling filter was designed and operated to remove NO from an air stream using bacteria extracted from the sewage sludge of a municipal sewage treatment plant. To obtain the best operation conditions for the biotrickling filter, orthogonal experiments (L9(3(4))) were designed. Inlet oxygen concentration was found to be the most significant factor of the biotrickling filter and has a significant negative effect on the system. The optimal conditions of the biotrickling filter occurred at a temperature of 40°C, a pH of 8.0 and a chemical oxygen demand of 165 mg/L in the recycled water with no oxygen in the system. The bacteria sample was detected by DNA sequencing technology and showed 93%-98% similarity to Pseudomonas mendocina. Moreover, a full gene sequencing results indicated the bacterium was a brand new strain and named as P. mendocina DLHK. This strain can transfer nitrate to organic nitrogen. The result suggested the assimilation nitrogen process in this system. Through the isotope experimental analysis, two intermediate products ((15)NO and (15)N2O) were found. The results indicated the denitrification function and capability of the biotrickling filter in removing NO.
authors: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
authors: Hejingying
authors: H
authors: Niu
authors: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. Electronic address: ycleung@hku.hk.
authors: Dennis Y C
authors: DY
authors: Leung
authors: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: Chifat
authors: C
authors: Wong
authors: Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: Tong
authors: T
authors: Zhang
authors: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: Mayngor
authors: M
authors: Chan
authors: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: Fred C C
authors: FC
authors: Leung
mesh_terms: D000393:Air Pollutants / Q000302:isolation & purification*; D000704:Analysis of Variance; D002516:Ceramics; D005374:Filtration; D009569:Nitric Oxide / Q000302:isolation & purification*; D058458:Nitrogen Cycle; D009587:Nitrogen Isotopes; D062065:Wastewater / Q000382:microbiology*
chemical_list: D000393:Air Pollutants; D009569:Nitric Oxide; D009587:Nitrogen Isotopes; D062065:Wastewater
keywords: NO reduction; Pseudomonas mendocina; biotrickling filter; isotope labeling; orthogonal experiment