Investigation And Source Apportionment Of Pollution In Baoshu River

At present,the problem of water pollution cannot be ignored.The governments have also begun to pay attention to prevent and control water pollution.Many localities have carried out heavy pollution water body control actions one after another.Chaohu Lake has important ecological effect and economic value.Nowadays,the severe eutrophication of Chaohu Lake is caused by human activities,resulting in the periodic outbreak of blue algae and serious damage to the ecological environment.In order to control the water pollution of Chaohu Lake,it is necessary to determine the pollution sources and the contribution of pollution around Chaohu Lake basin,and taking the principle of"one river,one policy"to improve the water quality of Chaohu Lake and reduce the pollution load of Chaohu Lake,so as to achieve the purpose of improving the water quality of Chaohu Lake.In view of the Baoshu river basin,one of the small watershed of the around Chaohu Lake,the investigation and analysis of the pollution sources were used to provide a reference for engineering treatment,and the sources of pollution in the river basin of the Baoshu river were investigated,and the main pollution sources such as the urban living source,the surface runoff and the agricultural non-point source in the basin were determined.In addition,using the APCS-MLR model to identify the main component of the pollution source,the paper evaluates the water quality in the dry season,the water level and the water quality in the high water season,and analyzes the ecological risk of heavy metal in the sediment of the project.The water environmental capacity and the reduction of the project demonstration section shall be calculated according to the surface class V water standard,and the water quality control measures shall be preliminarily designed and provided.The contents of the volume are as follows:?1?The results of the preliminary analysis of the water quality and the sediment in the section of the demonstration showed that the concentration of NH₃-N,COD and TP was in excess of the surface class V water standard,the level of heavy metal Cd in the surface sediments of the demonstration section was high,but the overall pollution level was low.According to the terrain elevation,the distribution of the regional drainage pipe network and the distribution of the main land types,the catchment area and the urban life source,the surface runoff pollution and the agricultural non-point source of the Baoshu river basin were determined respectively,and according to the John's model to calculate the pollution load.The annual load of COD,NH₃-N,TP into the river was 335.31 t/a,44.03 t/a and 3.95 t/a,respectively.The proportion of urban living pollution in COD,NH₃-N and TP into the river was 96.34%,99.48%and98.73%respectively.The proportion of COD,NH₃-N,TP was 20.81%,54.66%and24.52%respectively by introducing equal standard pollution load.The pollution sources of Baoshu River are analyzed by principal component regression model?APCS-MLR?.The results show that the discharge of nitrogen and phosphorus pollutants is the main cause of adverse effects on water quality,and the main pollution sources related to the pollution sources are domestic pollution and surface runoff in cities and towns.?2?The concentration of COD,NH₃-N and TP in the 16 monitoring sections in the basin was carried out in the low flow period,the normal flow period and in the high flow period,the water quality was evaluated by the single factor and the comprehensive pollution index method.The results showed that in the low flow period the rate of the over-standard sections of COD,NH₃-N and TP was 50%,75%and 25%respectively,in the normal flow period was 100%,75%and 100%respectively,in the high flow period was 93.75%,75%and 87.5%by the surface class V water standard and the total water quality was class V and inferior V.The results of comprehensive pollution index evaluation showed that the ratio of the minor pollution in the monitoring section was 6.25%,the moderate pollution was 43.75%,and the severe pollution was 43.75%in the low flow period.The ratio of the monitoring section of the serious pollution was 6.25%,and the severe pollution was 43.75%in the normal water period.The ratio of the monitoring section of the serious pollution was 56.25%,the severe pollution was 31.25%,and the serious pollution was 68.75%in the high flow period.?3?According to the one-dimensional steady-state water quality model,the water environmental capacity of COD,NH₃-N and TP of the water-holding river project was252.76 t/a,24.84 t/a and 2.57 t/a respectively.The reduction of COD,NH₃-N and TP pollutants were 82.55 t/a,19.19 t/a and 1.38 t/a respectively,according to the load of the pollutants into the river.The preliminary design of the pollution control scheme was carried out according to the reduction target,the dredging of the river channel and the construction of the three-dimensional ecological system are carried out,the dredging amount was 1350 m³according to the actual estimated river channel of the engineering demonstration section.Constructing a three-dimensional ecosystem of river that consists of emergent aquatic plants,submerged plants and benthic animals.