Study On Treatment Of Domestic Sewage By Anaerobic Fluidized Bed Bioreactor

Anaerobic fluidized bed reactor has the advantages of high load,low output,low energy efficiency and so on.In recent years,it has been shown a good prospect in the treatment of organic wastewater.In this paper,the fast start-up process of anaerobic fluidized bed reactor with granular activated carbon as carrier was studied;The low concentration sewage treatment and gas production situation,determine the optimal operation parameters,analyzed the characteristics of organic pollutants removal and transformation process.Experimental results show that under mesophilic conditions with high concentrations of organic matter inlet can achieve rapid growth of biofilm,microbial biofilm,the gradient reduce influent organic matter concentration method realized the stability of the reactor for low concentration domestic sewage treatment.The main influence factors on the reactor treatment effect showed that the carrier expansion degree of 30%to 80%range of changes for the COD removal rate is not affected.The COD removal rate can reach 94%when the degree of inflation is maintained at 30%.The hydraulic retention time of HRT was reduced from 12h to 4h,the volume load increased from 2.24 kgCOD/m3.d to 6.72 kgCOD/m3.d,the removal rate has little effect on COD.But the effluent volatile organic acid VFA accumulation increased from 75mg/L to 675mg/L,gas production from 71.58mL/gCOD.d to 30.91mL/gCOD.d.HRT 6h can achieve the optimal condition of reactor operation,the biogas yield was 36.97mL/gCOD.d,the removal rate of COD was 81%.Reactor temperature from 35 to 18 degrees Celsius in the process,VFA accumulation,effluent alkalinity and pH decreased.Reactor of microbes on the surface of granular activated carbon distribution uneven,upper carrier biofilm is thick,showing filamentous bacteria criss crossing the stable structure and lower thin.Electron microscope was used to observe the typical anaerobic microbial community,the sludge yield 0.12kgVSS/kgCOD.Compared with other anaerobic process and aerobic process,anaerobic fluidized bed reactor has wide application prospect in the low concentration domestic wastewater.