Degradation Efficiency Of Organic Compounds In Mixed Influent Water By Hydrolytic Acidification-Modified A~2O Process

Nowadays,most sewage treatment plants choose the activated sludge process for sewage purification.The treatment system has the advantages of high removal efficiency,strong self-purification ability and more stable in the process,but at the same time,the synchronous removal of nitrogen and phosphorus is also difficult to improve.The environmental conditions in different regions of China are different,and the influent pollutant concentration and quantity of sewage treatment plants in different regions are not the same,so the material competition among the microbial communities in the activated sludge system and the change of temperature,influent quality and quantity will affect the efficiency of sewage treatment plants.This study with practical operation of urumqi west station comprehensive sewage treatment plant as the research object,by combining A large number of historical operation data and the correlative tracking monitoring indicator,with the analysis of SPSS software such as the plant in 2019 with hydrolysis acidification-SBR for process improvement of feed water quality characteristics,the relationship between percentage of feed nutrients and existing problems of the original process,hydrolysis acidification-late for anaerobic/anoxic/aerobic process(A/A/O technology)provides data reference and theoretical support.The results are as follows:(1)Through SPSS software analysis,all the influent water quality indicators of the sewage treatment plant in 2019 all obey the normal distribution,except for SS and p H,the other indicators are negatively skewed;the influent TP,COD,NH4+-N in 2019 The cumulative probability that the inlet water quality indicators of TN,BOD5 and SS are higher than the inlet water design value are 71.50%,85.20%,87.20%,96.40%,87.40%,and 0.50%,respectively,indicating that each inlet water quality index exceeds the inlet water design value.value.(2)From the perspective of biodegradability,the probability that the B/C of influent water will be distributed between0.60 and 1 in 2019 is the highest,reaching 46%.Generally speaking,the biodegradability of influent water is better;From the perspective of nitrogen analysis,the cumulative probability of the influent C/N greater than 4 in 2019 is 55.80%,indicating that the carbon source that can be used by denitrifying bacteria in the influent is sufficient;From the perspective of biological phosphorus removal,the cumulative probability of influent BOD5/TP greater than 30 in 2019 is 73.40%,indicating that the content of organic matter in the influent water can basically meet the needs of biological phosphorus removal.In addition,the probability that the TN/TP ratio of influent water is greater than 5 in 2019 will reach 98.30%,which meets the optimal growth conditions required for microbial proliferation.(3)Based on the comprehensive analysis of the operation of hydrolytic acidification and improved SBR process,the average removal rates of COD,TP,NH4+-N,TN and SS in 2019 were 92.65%,84.68%,95.06%,63.62% and 84.68%,respectively.Only COD and NH4+-N meet the first grade B standard.Through the comprehensive analysis of the main problems existing in the original process,such as low denitrification efficiency and unstable phosphorus removal,the solutions for these problems are preset and compared.The rationality of environmental pollution such as sludge output and tail water discharge was analyzed.The process of "shallow air floating tank+hydrolytic acidification+transformation of A~2O (anoxic/anaerobic/aerobic)+high efficiency sedimentation tank+denitrifying deep bed filter+sodium hypochlorite disinfection" was finally determined.(4)In 2020,the actual production data comparison of the process of hydrolysis acidification-transformation of A~2 O for 7 consecutive months shows that after the process transformation,the average removal rates of COD,NH4+-N,TP and TN are as high as 95.87%,98.60%,96.70,respectively,91.20%,which were respectively an increase of 3.22%,3.54%,12.02%,and 27.58% year-on-year before the renovation.The effluent quality of this process is obviously better than the first-level A standard.Engineering practice has proved that both nitrogen and phosphorus removal have achieved good expected results.