Research On Nitrogen And Phosphorus Removal Efficiency Of Brewing Wastewater Based On MUCT Process

Research shows that about 70% of the water in chinese liquor can be transformed into waste water.Brewing wastewater has high content of organic matter,low p H,strong odor,and the concentrations of total nitrogen and total phosphorus are far higher than domestic sewage.In addition,it also contains some toxic substances,which can be discharged into the water body only after reaching the industry discharge standard.At present,the process of "Anaerobic +aerobic + Advanced Treatment" is widely used.In anaerobic section,COD in raw water is mainly removed,but the content of phosphorus in wastewater is inevitably increased;SBR,AAO,CASS and other processes are often used in aerobic unit,but in practical application,it is found that the above processes have some problems,such as unsatisfactory treatment effect,complex debugging and high cost.It is necessary to explore the treatment efficiency of other processes for brewing wastewater.As an improvement of UCT process,MUCT is often used to treat domestic wastewater with low C/N(1-2)and low TP concentration(< 10mg/L)with good results.The water quality monitoring of the winery wastewater treatment station carried out in the project found that the C/N in the raw water was as high as 49.38,and the content of TP was about 20mg/L.After anaerobic treatment,the C/N of the brewing wastewater was reduced to about 3,and the concentration of TP was about 30mg/L.In this paper,the MUCT process was used as an aerobic unit to treat the brewing wastewater with high nitrogen and phosphorus concentration,and the treatment effect of nitrogen and phosphorus elements was studied when the plant was in two stages of whole-process nitrification and short-cut nitrification respectively.The main research contents are as follows:(1)Rapid start-up of the reactor by measuring the relevant parameters of the sludge in the whole process and microscopic observation of the microorganisms in the sludge,combined with the quality indicators of the water in and out;(2)In the whole nitrification stage,the effects of different hydraulic retention time,carbon source dosage point and the process on the treatment effect of brewing wastewater under the condition of changing C/N by adding carbon source in anoxic tank I were investigated.(3)Study how to make the plant stably transition from the whole-process nitrification and denitrification stage to the shortcut nitrification and denitrification stage,and how to make AOB bacteria become the dominant species to stabilize the nitrite nitrogen accumulation rate(NAR).The experimental results are as follows:(1)By inoculating the sludge from the same type of brewing sewage plant,the start-up and commissioning period of the device is only 20 days.At the end of start-up,the sludge is honeycombed with good settling performance,and indicative microorganisms such as rotifer and clock worm can only appear when the water quality is good.The average removal rate of COD and total nitrogen reached 90% and 68.48%,respectively,and the maximum removal rate of total phosphorus reached 61.62%.(2)The single factor method is used to obtain that the optimal HRT for nitrification and denitrification in the whole process of MUCT treatment of brewing wastewater is 10 H,and the average removal rates of COD,ammonia nitrogen,and total phosphorus reach 89.60%,53.54%,and 62.87% respectively;by directly adding carbon source to the influent water It is found that it has little effect on the promotion of nitrogen and phosphorus removal,and the carbon source is replaced in the anoxic I zone.It is found that when the C/N of the anoxic I zone is 6,the process has the best effect on the treatment of simulated brewing wastewater.The average removal rate of total phosphorus can reach 66.17% and 74.03%,respectively.The removal rate of ammonia nitrogen and total phosphorus is 12.63% and 11.16% higher than that without carbon source.(3)In the short-cut nitrification stage,shorten the HRT to 8h and control the DO concentration from 0.5 to 0.8 mg/L,and use NAR as the index to distinguish the two-stage nitrification from the full-range and short-range nitrification.Finally,the short-cut nitrification and denitrification were successfully started when the mixed liquid reflux ratio was 150%,the nitrification liquid reflux ratio was 250%,and the return sludge ratio was 90%.In the raw water stage,the NAR is stable at about 60%,the ammonia removal rate is above 50%,and the average removal rate of TP reaches 77.94%,up to 91.59%.In summary,when using the MUCT process to treat actual brewing wastewater,whether it is the full nitrification and denitrification stage or the short-cut nitrification and denitrification stage,the process can well remove most of the COD,ammonia nitrogen and TP in the anaerobic effluent.However,in terms of cost saving,the realization of short-cut nitrification and denitrification based on the MUCT process is more suitable for the treatment of the new sewage treatment plant in the second phase of Jiannanchun and the treatment of the same type of industrial wastewater.If subsequent measures such as advanced treatment units(supermagnetic phosphorus removal)are used,the effluent can reach the industry discharge limit of the "Water Pollutant Discharge Standard for Fermented Alcohol and Liquor Industry"(GB27631-2011).