Study On Microbial Storage,Hydrogen Partial Pressure And Microbial Group In Anaerobic Biological Treatment

This paper investigated a serious of sludge changes caused by microbial storage under various operations in the following two glucose-fed reactors: anaerobic sequencing batch reactor (ASBR) and anaerobic continuous flow reactor (ACFR).There was glycogen storage in substrate metabolize of ASBR. Higher F/M led to more glycogen storage, less VFA directly degraded from substrate, and slower hydrogen-producing rate, lower hydrogen partial pressure in reactor. At the end of feeding period, hydrogen partial pressures were 20.5Pa and 15.4Pa in 0.10 and 0.14 F/M ASBR respectively.There was no glycogen storage in substrate metabolize of continuous flow reactor. Substrate degraded into VFA directly. Therefore, the hydrogen producing rate was faster during glucose fermentation, which led to a higher hydrogen partial pressure averaged of 57.3Pa.A batch test was conducted to study the effect of culture history on storage, which indicated that culture history and feeding pattern were both necessary for storage. Storage ability was owned by fermentation bacterial previously adapted to storage (usually named GAO), and the storage response was significant only with proper feeding pattern (high concentration and short-term feeding).In 0.14 F/M ASBR and continuous flow reactor, the maximum specific H2-consuming rate were 24.65ml/g.h and 60.81ml/g.h respectively, the maximum specific methanogenic rate were 6.134ml/g.h,15.62ml/g.h respectively.Estimate the proportions of methanogenesis autotrophic and acetoclastic bacteria in 0.14 F/M ASBR and continuous flow reactors, according to H2-consuming and acetate-consuming specific methanogenic activity. It turned out that, in 0.14 F/M ASBR and continuous flow reactors, the portions of methanogenesis autotrophic bacteria were respectively 1.9% and 4.8%, the portions of acetoclastic bacteria were respectively 3.4% (counted by methanosarcina) and 21.5% (counted by methanosaeta). The ratios of H2-consuming and acetate-consuming bacteria portions were 4:7 and 1.6:7 respectively. Different hydrogen partial pressures of different reactors can be explained by the different ratios of the two methanogenic groups and the balance of hydrogen-producing and hydrogen-consuming.The fermentation types were supposed to be propionic in ASBR and butyric in continuous flow reactors, according to VFA constituents, hydrogen production and sludge activity in different reactors.Accordding to microscopical results, speculated that methanosarcina was dominating in ASBR and methanosaeta was dominating in continuous flow reactors. Dissociated microbe of ASBR which had stored glycogen can be stained, and hyphomycetes in continuous flow reactors cannot be stained.