期刊名称：Universitatea Politehnica din Timisoara. Buletinul Stiintific. Seria Chimie si Ingineria Mediului
印刷版ISSN：1224-6018
出版年度：2009
卷号：54(68)
期号：02
出版社：Universitatea Politehnica din Timisoara
摘要：This paper presents the occurrence of ammonia in effluent from Timisoara sewage treatment plant (STP) and the assessment of risk it may pose to aquatic environment of Bega River. The risk assessment was evaluated according to the procedure laid down in European Union. Seven typical freshwater organisms were chosen as ecological endpoints: aquatic invertebrates ( Daphnia magna , Crangonyx spp . and Gammarus pulex ), fishes ( Pimephales promelas , Cyprinus carpio , Lepomis macrochirus ) and amphibians ( Rana clamitans ). An average concentration of 6.05 ± 1.47 mg NH4+-N/L (0.053 ± 0.025 mg NH3/L) was measured in Timisoara STP effluent. The ratio of predicted environmental concentration (PEC) to predicted no-effect concentration (PNEC), known as the risk quotient (RQ), was used for the risk characterization. The ammonia PNECs for G. pulex and L. macrochirus were lower than the PEC in Bega River, resulting in risk quotients greater than one. For D. magna , C. spp. , P. promelas , C. carpio and R. clamitans the derived PNECs were higher than the PEC, resulting in risk quotients less than one. Based on the assumption that ecosystem sensitivity depends on the most sensitive species, it is concluded that there is a definite possibility that aquatic environment of Bega River may be detrimentally affected by ammonia from Timisoara STP effluent. This evaluation will need to be improved on certain aspects, further actions being necessary in order to refine the risk assessment and to clarify the conclusions.
