Forecasting,Assessment And Remedy Technologies For Malodorous Black River Caojia In Harbin

Black and odorous water of urban will aggravate the shortage of water resources,destructing the landscape environment,making the water resources loss its functions,and it can also affect the health of the surrounding residents,causing headache,nausea and even damage to the central nervous system.The government took an investigation in 2016,it showed that there were 1861 maladorous black rivers among 295 prefecture level and above cities in china.Because the black and odorous water have great influence on the urban economic development and the health of the residents,its governance is imminent.Because black and odor water remedy is a systematic project.The causes of black and odor water,pollution status and influencing factors are different,it is necessary to propose a targeted governance program to achieve the governance of "one river,one policy".This research mainly monitored CaoJia Gou water quality and its changes.Using factor analysis to analyze the index method and determinate the main control factors and key indicators of black and odorous of CaoJia Gou based on monitoring data.Analyzed the relationship between the main control factors.Determined the removal rate of index by using BP neural network model.Finally,aeration and coagulation experiments were carried out,the removal effeciencies of pollutants were compared,and the water quality under the experimental conditions was predicted by the model.A suitable comprehensive treatment plan of Cao Jia Gou was put forward by selecting.The conclusions were as followed:The study showed that the water quality of Cao JiaGou was severe black and odorous water,and organic pollution and nitrogen and phosphorus pollution were very serious.The changes of DO,COD and NH4+-N were greatly affected by the location of sampling points.Through factor analysis,the main control factors of CaoJia Gou were COD,NH4+-N,PO43--P,DO,T and Fe,using DO as response indicators to establish BP neural network prediction model,the pre diction results show that when each index reduction reaches 20%,DO>2 mg/L,when each index reduction reaches 40%,DO>4 mg/L;At 18 degrees,each index reduction reaches 40%,DO>2 mg/L,the reduction of up to 60%,DO>4 mg/L.The higher the temperature,the higher the oxygen consumption rate of pollutants in water.The experiments of magnetic flocculation and aeration on CaoJia Gou samplyied water.The results showed that COD and phosphate removal rate of the magnetic flocculation could reach 89.77% and 98.14% respectively.Magnetic flocculation coule served as the water emergency treatment method,which could make the water restore good sensory effect quickly;COD removal rate of aeration method could reach 65%.By the dosage of activated sludge,the COD and ammonia nitrogen removal rate of aeration could increase to 86.96% and 84.14%,respectively.In the optimum conditions of aeration and magnetic flocculation combined,the removal rate of chroma,COD,NH4+-N,PO43--P,TP,Fe can reach 96%,99.42%,80.87%,100%,99.22% and 85.35% respectively,each index reduction was more than 80%,according to the forecast model,DO>5 mg/L,black and odorous water can be treated effectively.