Treatment Of Biogas Slurry By Short Cut Nitrification And Denitrification In An Integrated A/O Reactor

Under the emphasis of national and local governments on biomass energy,biomass anaerobic fermentation technology has been developed rapidly.the biogas slurry,as an anaerobic fermentation product,belongs to a high concentration of pollutants.If it can not be used effectively,it needs to be further processed before it can be discharged.Shortcut nitrification and denitrification technology has great advantages in the treatment of waste.To avoid environmental pollution due to the direct emissions of anaerobic biogas slurry,This research developed a set of small one-piece A/O biofilm and activated sludge composite reactor,it has the features of simple installation and maintenance,compact structure,convenient handling,saving land area and changeable function,and a shortcut nitrification and denitrification was carried out on a straw pig manure mixed with fermentation broth and a pig farm biogas slurry.We draw the following conclusions:?1?By adding ammonia oxidation and denitrifying bacteria developed by laboratory,the method of rapid start-up of integrated equipment was studied,and the process of one-piece A/O short-range nitrification and denitrification was successfully implemented in 17 days.?2?During the system stable operation stage,when the water intake is the raw water of pig manure and HRT is 10d,the average removal rate of COD,ammonia nitrogen and total nitrogen was 92.2%,97.0%and 90.1%,respectively,and the average nitrogenous nitrogen accumulation rate of aerobic pool was 91.4%,The average organic volume load of the system was 1.13KgCOD/m³/d,and the average aerobic nitrogen load was 0.11Kg NH₃-N/m³/d.?3?According to the characteristics of water quality fluctuation of biogas slurry,the water quality impact test was carried out.The water intake was the biogas slurry of different sources,HRT was 7d,its COD was 1635.2-15308.2mg/L,ammonia nitrogen was 181.4-944.3mg/L,total nitrogen was 248.0-947.0mg/L,in the system,the average removal rate of COD,ammonia nitrogen,total nitrogen was 86.0%,96.0%and 89.5%respectively,the average nitrate nitrogen accumulation rate was 85.0%.When the water quality changes violently,the system has a stable removal rate of the pollutants.?4?According to the difference of biogas slurry carbon nitrogen ratio,inspected the system's pollutants treatment effect under different carbon and nitrogen ratio,the results show that the effect of carbon and nitrogen ratio on total nitrogen removal was greater than that of ammonia nitrogen and COD removal.When the carbon nitrogen ratio was 10.8,the average removal rate of COD was 92.0%,the average removal rate of ammonia nitrogen was 94.6%,and the average removal rate of total nitrogen was 92.6%.When the carbon nitrogen ratio was 8.2,the average removal rate of COD was 87.6%,the average removal rate of ammonia nitrogen was 93.6%,and the total nitrogen removal rate was 89.6%.When the carbon nitrogen ratio was 6.0,the average removal rate of COD was 83.2%,the average removal rate of ammonia nitrogen was 91.4%,and the total nitrogen removal rate was 86.7%.Due to the total nitrogen was higher when the carbon nitrogen ratio was 6.0,so the system was optimized and regulated.In the regulation stage,when the carbon nitrogen ratio of water intake was 6.4,the average removal rate of COD was 85.6%,the average removal rate of ammonia nitrogen was 91.2%,and the total nitrogen removal rate was 86.9%.The total nitrogen removal rate increased to 92.2%in the late stage of regulation.When the carbon nitrogen ratio was 4.2,the average removal rate of COD was 79.0%,and the average removal rate of ammonia nitrogen was 95.9%.The average removal rate of total nitrogen was 80.6%and the total phosphorus removal rate was 79.0%.In addition to when the carbon and nitrogen ratio was 4.2,the ammonia nitrogen and total nitrogen of the discharged water after the system treatment all can meet the requirements of"The standards for pollutant discharge in livestock and poultry industry"?the second consultation draft,Public letter of the general office of the ministry of environmental protection[2014]335?.After the coagulation treatment of the effluent,all the indexes meet the emission requirements of the livestock and poultry industry pollutant emission standard?GB18596-2001?.