Abstract
p-Nitrophenol (PNP) is a toxic compound which enters the environment through various industrial sources. For its biological degradation, cultivation and acclimation of p-Nitrophenol degrading microorganisms is essential. During the initial cultivation of p-Nitrophenol degrading biomass from activated sludge in this study, the mixed liquor suspended solids (MLSS) concentration dropped steadily requiring the need of a second easy-to-degrade carbon source for biomass growth. Five second carbon sources namely glucose, phenol, urea, aniline and yeast extract were examined for their utilization as a co-sutbstrate in p-Nitrophenol degradation. p-Nitrophenol degradation, total organic carbon (TOC) disappearance and biomass growth were investigated. Glucose and yeast extract were found to be suitable co-substrates, however, from the points of view of cost, specific p-Nitrophenol degradation rates and self degradation, glucose was preferred over yeast extract. Thus, use of glucose is recommended as a second carbon source in the acclimation and growth of p-Nitrophenol degrading biomass. A glucose concentration range of 100 to 1000 mg/l can be used depending upon the desired rate of biomass growth.
