Study On Effect Of High Concentration Dissolved Oxygen Water On The Performance Of Sanitary Sewage By SBR Process

Water is the source of human life.However,the problems of water resource pollution and shortage are becoming more and more serious.One of the biggest sources of water pollution is the domestic sewage.In recent years,our country's domestic sewage discharge is increasing year by year.By 2018,our country's total domestic sewage discharge reached 62.00 billion tons,accounting for 78.0% of the total wastewater discharge.The development of technologies that can efficiently treat domestic sewage is in line with the current development trend of the times.Micro-nano bubble technology has become one of the research hotspots in recent years.Micro-nano bubbles have characteristics not found in ordinary bubbles,such as small bubble diameter,long residence time in water,and strong oxidizability.In this paper,high-density dissolved oxygen water is prepared by means of pressurized dissolved gas and charge of oxygen.The prepared high-concentration dissolved oxygen water contains micro-nano bubbles with a diameter of less than 50?m.In this paper,oxygen and air are as different gas sources,the effects of different mixing pressures and inlet water temperatures on the dissolved oxygen content of the water body were studied.On the basis of oxygen as an oxygen supply source,the bubble suspension time and the effective gas-liquid mixing ratio were measured,and the stability of the prepared high-concentration dissolved oxygen water was studied.In addition,the research on the effects of high-concentration dissolved oxygen water aeration technology and traditional blast aeration technology on the treatment of pollutants in domestic sewage has been done separately.By comparing the differences between the two,we can further understand the high-concentration dissolved oxygen Water application prospects.On this basis,the effect of different sludge concentrations on the removal rate was also studied.The conclusions drawn in this experiment are as follows:(1)The oxygen content of dissolved oxygen water prepared by oxygen is far greater than that prepared by air.When the temperature is 25? and the mixing pressure is 0.45 MPa,the dissolved oxygen water prepared by oxygen has the best effect,and the oxygen content can reach 43.6mg/L.(2)The average residence time of micro-nano bubbles in the high-concentration dissolved oxygen water prepared under the best conditions is 1 minute and 28 seconds,the volume ratio of bubbles in the mixed liquid is at least 1.7%.(3)Under good storage conditions,although the oxygen content of dissolved oxygen water has decreased over time,it still has a high level of dissolved oxygen content after 7 days of storage,and the dissolved oxygen content reaches 31.3 mg/L.(4)The use of high-concentration dissolved oxygen water aeration technology can increase the dissolved oxygen content in sewage to 3.4 mg/L.From the test results,it can be seen that the high-concentration dissolved oxygen water aeration technology is significantly higher than the traditional blast aeration technology,and the removal rate of high-concentration dissolved oxygen water aeration to COD,ammonia nitrogen,TP is 19.2%,15.5% and 13.6% higher than that of the ordinary blast aeration gas technology respectively,and the removal rate of pollutants in water bodies by high-concentration dissolved oxygen water is faster.(5)The study on the removal rate of pollutants in sludge showed that when the sludge concentration is 3000-4000 mg/L,the removal effect of each pollutant is the best.When the sludge concentration exceeds 4000m/L,the maximum removal rate of each pollutant will decrease to varying degrees.