The Effect Of Particle Carriers On Start-up And Operationg Performance In Up-flow Anaerobic Sludge Blanket (UASB)

UASB is widely used in industrial wastewater treatment with the advantages of high efficiency,stable operation and energy-saving,however,the UASB reactor start-up is slow and difficult which has greatly restricted its industrial application.In this study,sludge granulation process,biological degradation performance and resistance ability in traditional UASB(R1),and UASBs with diatomite(R2),turfy soil(R3)and maifanite(R4)were investigated with oily refinery wastewater.The microbial community structure in each reactror during different stage was also analyzedThe results showed that:(1)the addition of the support material required an initial adaptation period for the development of microbial communities,and the adaptation period from longest go to shortest in turn is diatomite,maifanite and turfy soil.(2)Diatomite,turfy soil and maifanite addition improved pH tolerance and enhanced biological degradation performance in UASB system.At stable period,the average COD removal of R2,R3 and R4 were 92.42%,91.67%and 92.44%with OLR from 8 to11 kg COD/(m~3�d),respectively,which were higher than R1's(89.42%).The results of GC/MS also proved the UASBs with support materials had stronger pollutant degradation performance than control.(3)Diatomite,turfy soil and maifanite could enhance granulation.After 152 days operation,the granules larger than 0.90 mm in R2,R3 and R4 accounted for 10.52%?22.72%and 18.53%,respectively,which was significantly higher than that of R1(5.63%).SEM results revealed that three surport materials could provide the initial"nuclei"for granulation,the microbes attached and aggregated on the surface of carriers,the sludge granules were formed finally.(4)High throughput sequencing analysis showed support materials addition affected the diversity and structure of microbial communities.The reactors with additions were more adaptive to the changes of the influent substrate,and the microbiology diversity in R2,R3 and R4 were increased compared to R0 when using oily refinery wastewater as the sole carbon source.The increase of hydrolytic acidification bacteria ensured the efficient operation of the UASB.In conclusion,diatomite,turfy soil and maifanite addition not only enhanced granulation,but the performance of UASB system,which had good application foreground.