Analysis Of Fractal Structure And Microbial Characteristics Of Granular Sludge In ABR

ABR(Anaerobic Baffled Reactor) is a new high-efficiency anaerobic bio-reactor which has been playing an important role in wastewater reusing.In this thesis,fractal dimensions and microbial characteristics of granular sludge in ABR treating low-strength wastewater at different HRT was analyzed,with a comparison of another ABR treating high-strength wastewater in a starting process.Results of ABR treating low-strength wastewater showed:As HRT gradually reduced from 24h to 5h,the COD removal rate of ABR was mostly above 90%in steady running periods.The first two compartments performed the main COD removing work in the beginning,and then did the middle three compartments as HRT becoming shorter.The tendency of MLVSS/MLSS ratio in the former three compartments higher than that in the latter two ones was becoming more remarkable. Methanobrevibacter in former compartments and Methanothrix in latter compartments was the main microorganism species in ABR.Methanococcus appeared in every compartment of each running period, and Methanosarcina accounted for 12.8%of Archaea.The EPS content played positive roles in COD removal and the stability of granules for its relativity to the MLVSS concentration and d₅₀.The d₅₀ became bigger in the former four peiriods,but changed smaller at HRT 5h.The D₁ and D₂ of granular sludge behaved inversely in compartments of ABR at the same HRT,that is to say,the granular sludge along the ABR sequences became smoother on the surface meanwhile more compact structurally.Comparison of ABR treating high-strength wastewater in a starting process showed:Under the influence of influent concentration and EPS,the 1^st compartment of ABR performed the most COD removing work.The contents of Methanococcus were higher which accounted for 22.7%of Archaea. Furthermore,the EPS contents had the same trend with D₁ of granular sludge.