Experimental Investigation Of Enhancing Nitrogen And Phosphorus Removal Process For Treating Municipal Wastewater Based On The Deep-shaft Aeration

In recent years, the Songhua River pollution is very serious, and Majiagou river is an important tributary of the Songhua River, Majiagou’s water quality affects the Songhua River’s water environment and the living standards of the people of Harbin directly. For this situation, after analyzing the water quality of chaoyang section of Majiagou river and researching a lot of data, this article selected deep-shaft aeration to deal with the sewage, so that we can guide chaoyang wastwater treatment plant’s designing and Operation in Harbin. With the support of "National Science and Technology major projects ", the test found a best operation condition by adjusting the operation parameters.At the same time,the test simulates deep-shaft aeration using a high pressure reactor,which can study the role of the degradation of pollutants,the condition of the dissolved oxygen and the utilization of air and oxygen.Finally, the article studied the diversity of microorganisms and microbial community using high-throughput sequencing methods.Deep well aeration test used the real wastewater in majiagou river,by adjusting the ratio of anaerobic and anoxic influent parameters 3: 1,2: 1,1: 1,1: 2,1: 3,sludge return ratio of 15%, 30%, 50%, 70%, 90%, nitrification liquid reflux ratio of 150%, 200%, 250%, 300%, 350%, DO of aeration tank of 2mg/L, 3 mg/L and 4 mg/L,SRT of 7d, 10 d, 13 d, 16 d to examine the system to remove the effect of COD, ammonia nitrogen, TN, TP, and get the best operating point,which is anaerobic and anoxic water ratio is 1: 3, the sludge reflux ratio is 50%, nitrification liquid reflux ratio is 200%, SRT is 13 d, DO level of anaerobic tank is 0.2 mg/L or less, Anoxic tank 0.3 ~ 0.5 mg/L, aerobic is about 3.0 mg/L. At this time,if the reactor influent simulated Majiagou river’s actual water quality,the COD, ammonia nitrogen, TN, TP of the reactor effluent can meet the national emission standards(GB18918-2002).High pressure reactor test is divided into fixed pressure test and gradient pressure test. Fixed pressure test control the reactor running under a certain pressure condition from 0.0 Mpa to 0.7 Mpa,which pressure run 3.0 h, the COD and NH3- N and NO3-N, TP removal, pressure change over time. It inspects the change of COD, NH3- N, NO3 –N and TP with the change of time and pressure. Gradient pressure test control the reactor running under a changing pressure condition from 0.0 Mpa to 0.7 Mpa,each pressure condition remainds 15 minutes,20 minutes,25 minutes. It inspects the change of COD, NH3- N, NO3 –N and TP with the change of time of each pressure. According to the rule,we can calculate the chaoyang wastwater treatment’s effects. In fixed pressure test, by analysising the volume of entering gas,exhaust gas,the oxygen content in the exhaust gas and the efficiency of pollutants removal,we got a rule, which is the volume of air and oxygen to removal the unit mass of pollutant. Experimental results show that with the increase of pressure, pollutants removal efficiency and the utilization of air, oxygen, are all increased to different extent.The article studied the diversity of microorganisms and microbial community using high-throughput sequencing methods. The sludge samples in the test are respectively form anaerobic tank, anoxic tank, aerobic tank, Sewage sludge and sludge which suffering high pressure training.Experiment analyzed the diversity and differences between the various samples, and it also analyzed microbial community composition through phylum,class,genus. Combining with the composition of microorganisms in the sample and phenomenon of the test,we explored more characteristics of deep well aeration.Study for the future practical engineering application of the technical and economic analysis, the results show that the songhua river water special sewage plant based on the deep well aeration process to strengthen the denitrification and dephosphorization process. Can alleviate in the effluent standard, on the basis of the status quo of land tensions, adopting the technology covers an area of about 28600 m3, about 50% of the normal process, the secondary treatment process can save a covers an area of about 80% compared with other processes. Also greatly reduce operating costs and can save operating cost 1.3688 million yuan a year.Test results applied to the song hua river water special sewage plant, can achieve depth to reduce pollutants, improve the songhua river water quality, achieve the efficient use of dissolved oxygen in wastewater treatment, to realize saving energy and reducing consumption. Solve the winter in the northeast sewage treatment plant covers an area of big, the problem of low efficiency, the research results of t his project has good social benefit, economic benefit and environmental benefit.