title: Effect of short-term exposure of selected aromatic nitrogen compounds on wastewater treatment.
abstract: The biodegradation of melamine and p-nitrophenol (PNP) and their impact on wastewater treatment was evaluated after a short-term individual chemical loading in activated sludge treatment systems. Melamine was not degraded and quickly washed out of the system. PNP was degraded, but it led to a prolonged period of nitrification inhibition and deterioration of effluent quality. Both melamine and PNP loadings increased the effluent nitrogen concentrations, with their main contributors being melamine and NH4+, respectively. Nitrosomonas and Nitrospira were dominant in the activated sludge. Melamine did not affect the nitrifying assemblages, whereas PNP led to a reduced Nitrosomonas population size and complete washout of Nitrobacter. The results suggest that melamine is an inert compound if it enters the treatment facility for a short duration. Although the short-term exposure of melamine or PNP decreased effluent water quality,the impact of such aromatic nitrogen compounds on wastewater treatment performance may vary significantly. Water
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Atreyee
authors.initials: A
authors.lastname: Sims
authors.forename: Shashikanth
authors.initials: S
authors.lastname: Gajaraj
authors.forename: Donglei
authors.initials: D
authors.lastname: Wu
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Hu
mesh_terms: D001419:Bacteria / Q000145:classification / Q000378:metabolism; D019149:Bioreactors; D009596:Nitrophenols / Q000737:chemistry*; D013997:Time Factors; D014227:Triazines / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D009596:Nitrophenols; D014227:Triazines; D062065:Wastewater; D014874:Water Pollutants, Chemical; C011907:melamine; C024836:4-nitrophenol