title: Effect of organic toxicants on the activity of denitrifying granular sludge.
abstract: Denitrification plays a key role in the biological nitrogen removal from the wastewater using granular sludge as the integral part of a high-rate denitrification technology. It is helpful to evaluate the effect of typical organic toxicants on the activity of denitrifying granular sludge for the application of denitrification technology. In this study, four typical organic toxicants, namely, penicillin, chloramphenicol, 2,4-dinitrophenol and polymyxin B sulphate were used to assess the effect of organic toxicants on the activity of denitrifying granular sludge. The results of individual toxicity indicated that penicillin, chloramphenicol and 2,4-dinitrophenol had significant inhibition, whose half-inhibitory concentrations were 0.534, 0.162 and 0.474 g/L with respective inhibitory magnitudes of 90.79%/(g/L), 282.5%/(g/L) and 138.83%/(g/L). Polymyxin B sulphate showed no significant inhibition. The results of combined toxicity indicated that the binary mixture of penicillin and chloramphenicol had an antagonistic effect, both the binary mixture of penicillin and 2,4-dinitrophenol and the binary mixture of chloramphenicol and 2,4-dinitrophenol had additive effects. The ternary mixture of penicillin, chloramphenicol and 2,4-dinitrophenol had a partial additive effect.
authors.affiliation: a Department of Environmental Engineering , Zhejiang University , Hangzhou 310058 , People's Republic of China.
authors.forename: Zonghe
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Ru
authors.initials: R
authors.lastname: Wang
authors.forename: Abbas
authors.initials: A
authors.lastname: Ghulam
mesh_terms: D019297:2,4-Dinitrophenol / Q000633:toxicity*; D002701:Chloramphenicol / Q000633:toxicity*; D058440:Denitrification / Q000187:drug effects*; D010406:Penicillins / Q000633:toxicity*; D011112:Polymyxin B / Q000633:toxicity*; D018505:Waste Management
chemical_list: D010406:Penicillins; D002701:Chloramphenicol; D011112:Polymyxin B; D019297:2,4-Dinitrophenol
keywords: denitrifying granular sludge; organic toxicant; specific activity; toxicity assessment