Treatment Of Actual Waste Water By Aerobic Granular Sludge And Screening Of Tylosin-Degrading Bacteria

Aerobic granular sludge technology is the most widely used water treatment technology,with advantages of strong processing capacity,small amount of excess sludge,and small floor space.However,the formation mechanism of aerobic granular sludge is not clear,and there are many influencing factors in the cultivation process of aerobic granular sludge.In order to explore the influencing factors of different types of activated sludge formation,three different sources are selected in this paper.At present,most aerobic granular sludge technology is only studied in the treatment of simulated wastewater.The treatment of actual wastewater by aerobic granular sludge technology is not clear.Therefore,three different types of actual wastewater are selected for treatment and screening.A strain that is capable of efficiently degrading specific contaminants in pharmaceutical wastewater.In order to study the influence of the source of activated sludge on the cultivation of aerobic granular sludge,the subject selected from the sludge of the animal husbandry,the sludge of the pharmaceutical plant and the sludge of the domestic wastewater treatment plant were cultured in a sequencing batch reactor.The results showed that the aerobic granular sludge was cultured on the 25th,28th and 31 st day after cultivation,which was related to the bacterial flora structure.The content of Flavobacterium in the sludge of the animal husbandry is the highest,and the genus plays a certain role in the granulation process of the sludge,so the AGS was granulated well.The content of Thauera in the sludge of the domestic wastewater treatment plant is the highest,whose genus is capable of degrading various pollutants in the water.Which is the main functional bacteria in the granular sludge.Therefore,domestic wastewater treatment plant sludge has the best degradation efficiency for pollutants such as COD.After a single cycle process,it was found that the aerobic granular sludge had better effect on the removal of pollutants when the pharmaceutical wastewater was used as the influent substrate compared to the oxidation pond wastewater and domestic wastewater.In the process of continuous treatment,although the composition of pharmaceutical wastewater is complicated,the sludge concentration can still increase to 4852 mg/L and the SVI is 53 mL/g,and the degree of granulation is higher.Granular sludge is still able to maintain a stable structure without breaking.The removal rates of pollutants in the continuous treatment of pharmaceutical wastewater were:COD removal rate of 88%,ammonia nitrogen removal rate of 96%,total nitrogen removal rate of 61.6%,and total phosphorus removal rate of 82%.The removal rate of the specific antibiotic tylosin in pharmaceutical wastewater reached 77.3%.The addition of tylosin to simulated wastewater can attribute to the process of aerobic sludge granulation.Whose structure is more dense than the sludge without added tylosin.The degradation rate of tylosin by sludge in RA was 66.6%.The strains which can efficiently degrade tylosin are screened by inoculating the granular sludge sludge strain in the liquid medium to which tylosin is added.The strain was identified by 16S,which is a genus of Klebsiella that is resistant to tylosin and can efficiently degrade tylosin.In the strain screening process,the degradation rate of tylosin was almost 100%,achieving complete degradation of tylosin.