| The exogenous pollutions were the main factors for urban rivers polluting in Hangzhou. In this study, the characteristics of exogenous pollutions and its influence on the main urban rivers were investigated purposely. It had important practical significance to improve the water quality of rivers in urban area.First of all,21urban rivers were selected to investigate the distribution of drainage outlets along them. By analyzing wastewater samples of these rivers in monitoring point and drain outlets respectively, the results showed that the ammonia nitrogen, total phosphorus were the main pollutants in these rivers in Hangzhou. The drainage outlets with the characteristic of domestic pollution were the main sources of pollution. Based on the investigation of drainage outlets, mapinfo software was used to preliminary establish the geographic information system of the urban rivers’pollution in Hangzhou. This geographic information system took the advantage of intuitive to blend the water quality, the position and the specific location of drainage outlets in it in Hangzhou urban river.Secondly, the characteristics of urban rainfall runoff, free fall and its impact on urban river were analyzed. The results showed that the main pollution indexes were ammonia nitrogen, total phosphorus and CODMn in urban rainfall runoff and the main pollution index of the free fall was total phosphorus and CODMn.Compared with water quality before rain and in the early rainfall stage, the total phosphorus showed a significant change but other indexes were stable. It was hard to describe the influence of urban rivers by the rainfall. However, the three dimension fluorescence spectrometry analysis could detect the influence of rainfall on waterin urban rivers quickly when the rainfall intensity was increasing.Jasminum nudiflorum was selected as typical representative of the vine-like shrubs to study the characteristic of pollutants captured by vine-like shrubs along the bank and influence on urban river water quality due to rain washing. The results in summer showed that the average value of per unit weight of Jasminum nudiflorum reached4.25mg/kg of Zn,0.53mg/kg of Cu and0.27mg/kg of Pb. The maximal value of ammonia and CODMn were8.95mg/kg and277.75mg/kg. According to the analysis of volatile and semi-volatile organic components with GC/MS, their organic compositions were similar. It implied the long-term effects of vine-like shrubs on urban river water quality.Finally, preliminary suggestions were put forward aiming at the governing of exogenous pollution in urban river. |
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