Practical Technology And Microbial Community Ecology Of Anaerobic Baffled Reactor

Anaerobic Baffled Reactor (ABR) is the third-generation new anaerobic apparatus developed according to the theory of Staged Multi-Phase Anaerobic Reactor (SMPA). ABR became the research hotspot for environmental scientists the minute it aroused. In this research, based on the operation of an ABR with 7 compartments, the regulation of microbe community alternation and community succession, as well as the control strategy of engineering operation were study by employing PCR-SSCP fingerprinting analytical technique. Two new-type ABR were developed and successly used in bio-hydrogen production by wastewater fermentation and soyprotein wastewater treatment respectively.Based on studies of organic matter degradation process and microbial ecology, intellectual view was put that acetogenic hydrogenogenic stage was the limiting stage of anaerobic digestion, which had been proved right by experiments, and made an important complement to the conventional theory that the methanogenic stage was surely to be the first limiting stage due to the strict living conditions required of methanogens.Based on study of engineering control strategy, ABRⅢ(ZL200420063866.9)for wastewater treatment was successfully researched and developed, and expressed highly efficiency in treating soy protein wastewater. With inoculation of aerobic activated sludge(18.0 gVSS/L), HRT 48 h, temperature 35℃, inlet COD concentration elevating from 2000 mg/L to10000 mg/L, the removal rate of COD stablized at 97% after 93 days'running and the granular sludge became grown up in every compartment.ABRⅡ(ZL200410044082.6) apparatus for hydrogen producing by fermentation was also researched and developed. At similar running conditions, the yield and specific conversion rate of hydrogen were both higher in ABR than in CSTR. with inoculation of aerobic activated sludge, employment of molasses wastewater as substrate, inlet COD concentration 5000 mg/L, HTR 13.5 h and temperature 35℃, the specific yield rate of hydrogen of activated sludge in ABR system was 0.13 L /gVSS?d, the specific yield rate of hydrogen of substrate was 0.13L/gCOD, which were both higher than in CSTR system under similar conditions. Appreciable specific yield rate of hydrogen was also obtained during the hydrogen producing from soy protein wastewater by anaerobic fermentation bacteria in ABRⅢ.Disclosed the regulation of microbial community succession in a seven-compartment ABR system, and defined the spatial niche of Hydrogen-Producing Acetogens(HPA) community. As the ABR system run stability with inlet COD concentration up to 4000 mg/L, hydraulic retention time (HRT) up to 2d,and initial alkalinity up to 2000 mg/L, the microbial community structure did not alter with the running continuing, which was proved by SSCP profiles techonlogy. The microbial community alternation in ABR system were: the fore-three compartment was dominated by hydrolytic bacteria represented by Escherichia and HPA; the fourth compartment displayed wide bio-diversity in functional community, it might be the transitional stage in community alternation system; the fifth compartment was the climax community of acedogenic represented by anaerolinea, and was also consisted of by a large amount of methanogens. The sixth and seventh compartment mainly consisted of methanogens. However, structures of microbial community were different from one compartment to another, the superior place of methanobateria was slowly replaced by methanogenium with wider ecological niche, and methanosarcina came into existence at this moment. The fifth compartment was where acetogenic hydrogenogesn exhibited great functions, but many other strains also existed, displaying wide bio-diversity. Three unreported Eubacteria and seven unreported Archaea were discovered and registering successfully at GenBank by cloning of SSCP profile, which is importance for study on anaerobic microorganism.This research offered engineering controlling strategies for ABR system, disclosed the regulation of microbial community alternation and community succession, also it studied on the applied technology, can be guide of theory and technology to engineering application.