Research On The Prevention And Control Of Water Pollution In The Baoji Section Of The Qianhe River Based On The Water Environment Capacity

Water environmental carrying capacity is an important quantitative index for scientific development of water pollution control countermeasures,maintaining water ecosystem health and achieving sustainable economic and social development.To study water environmental carrying capacity of the river.Propose total pollution source countermeasures,not only provide theoretical basis for the quantitative control of pollutants in watershed,but also support for regional development planning and watershed water environment management.This paper selects the Baoji Qianhe River as the research object,application of one-dimensional and two-dimensional water quality model method in sub-section,using synchronized water quality monitoring data to derive the comprehensive attenuation coefficient of water quality of each control unit,study and calculate the water environment carrying capacity,combined with historical cross section data,analyze the change of water quality and the trend of pollution evolution.The results show:?1?Using the wither frequency year p=75%.Qianyang section adopted to two-dim ensional model,and the one-dimensional model is used to Long County and Fengxian g section.In 2015-2017,the average water environmental carrying capacity of Qianhe Baoji section was COD 3561 t/a,NH₃-N 280 t/a.?2?Status?2017?Qianhe River Baoji section only point source pollutant COD 572.7 t/a,NH₃-N 75.92 t/a,Non-point source pollution pollutant COD 2603.85 t/a,NH₃-N 258.68 t/a,estimate by the remaining environmental carrying capacity of the Qianhe river Baoji section:COD 384.45 t/a,NH₃-N-54.54 t/a.?3?Analyzes the changes of water quality monitored by the Qianlong junction section and the Qianyang Bridge section in the past 10 years,The water quality of the section monitoring reached"surface water environmental Quality standard"Gb3838-2002?type,the COD?NH₃-N concentration is basically stable,the TP concentration changes greatly and shows an upward trend.However,the TN in the Fengjiashan Reservoir exceeded the standard since 2014,and the TP of the Qianhe River entrance in 2015-2016 exceeded the standard.The monitoring water quality reached the inferior V.In 2017,the NH₃-N concentration in the Qianhe reached a critical value,confirming the calculation.The NH₃-N in the Qianhe River Baoji section has exceeded the water environment capacity.It should arouse great attention to the prevention and control of water pollution in the Qianhe River Baoji section.?4?The pollution of the Qianhe River Baoji section is mainly caused by domestic pollution including rural non-point source pollution,livestock and poultry breeding,agricultural production,and residents'lives,followed by industrial pollution.Among them,domestic pollution accounted for 84.6%,and industrial pollution accounted for 15.4%.Based on the residual environmental capacity and water quality target of the aqueous environment functional area,this paper puts forward some suggestions on total pollutant emission control:In the upper reaches of the Qianhe River Baoji section,Long County and Qianyang County,have developed a large-scale livestock and poultry breeding by adjusting the agricultural industrial structure and raising the appropriateness of breeding and breeding.The Fengjiashan Reservoir Protection Area has implemented the conversion of farmland to forests,started the construction of green agricultural product bases,and controlled the use of pesticides and chemical fertilizers.Reduce agricultural non-point source pollution.The river pollution from Changqing Town to Qianhe River is serious.The industrial planning of Changqing Chemical Industry Park is moderately adjusted.The phosphorus-related and heavy-duty metal enterprises should be relocated,and ecological restoration should be started as soon as possible to ensure the ecological basis.Frestore the self-purification ability of water.Along the river industrial Park combined with the actual,strengthen the recycling of waste water,domestic sewage treatment plant should carry out deep treatment of sewage,improve the reuse rate of water;Strengthen the construction of rural sewage pipe network,improve the collection rate and treatment rate of rural domestic sewage.Establish measures such as long-term ecological compensation mechanism in the upper reaches of the Qianhe River to promote the coordinated development of county economy,society and environmental protection.