Analysis Of Influencing Factors Of Purification Efficiency In Fuzhou River Constructed Wetland

Water resources in the rapid economic and social development,population growth and living standards continue to improve the situation,showing a growing trend of water pollution.As an important part of water resources,rivers are also under great environmental and ecological pressure.As predicted by many scientists,if the water environment is not valued,it will lead to the loss of the environment that human beings rely on.The indiscriminate dumping of domestic sewage,discharge of substandard or even untreated industrial wastewater,rural animal husbandry,pesticides,fertilizers and other non-point source pollution and other problems directly or indirectly aggravate the pollution of river water.Fuzhou river is one of the important domestic and agricultural water sources of wafangdian city and surrounding villages in dalian.In order to ensure the safety of drinking water for residents and restore the ecological function of water environment,dalian city has taken many measures to improve water pollution,including the exploration and trial work of artificial wetland and other technologies.Based on the constructed wetland test site of caifangshen bridge,fuzhou river,water quality indexes such as solid suspended substance,total nitrogen,nitrate nitrogen,chemical oxygen demand,total phosphorus,nitrite nitrogen,five-day biochemical oxygen demand,ammonia nitrogen and so on were tested in the laboratory,and the water quality data obtained in the past 4 years were analyzed.The main work contents were as follows:First of all,using the spatial analysis function of ArcGIS to total nitrogen,nitrate nitrogen,ammonia nitrogen and dissolved oxygen,according to the test data visualization according to different color can be made the water quality data in internal distribution of wetlands,and analysis and the correlation of dissolved oxygen,second part analysis the wetland dissolved oxygen shortage,need to be in the second row between the rows of 3(superscript rd)to join the measures of increasing oxygen increase oxygen supply.Second,the influence factors of the overall purification ability of wetland analysis: the analysis of different inlet concentration,plant,and the matrix different influence on wetland purification effect,found in certain concentration range,the removal rate of wetlands for water quality index with the water quality concentration increases,and the yellow flag and gravel compared with reeds and pebble has better purification effect.And use the MATLAB BP neural network model to predict water quality data,forecasting when the wetland exit total nitrogen and ammonia nitrogen to surface water environment quality standard ? class water standards,at the entrance to the wetland 5 total nitrogen,ammonia nitrogen,biochemical oxygen demand(cod)and total phosphorus density,for the environmental protection department and government in controlling the discharge standard of sewage factory to provide the reference.Finally,the purification effect of constructed wetlands was affected by seasonal factors during the three years of constructed wetland management,and the removal rate of water quality indexes in the constructed wetlands with and without plant harvesting measures was analyzed,and it was concluded that plant harvesting had a positive effect on the removal rate of constructed wetlands.At the same time,the purification effect of constructed wetlands in the natural state without artificial management was analyzed to provide data support for the subsequent treatment of abandoned pilot test constructed wetlands.