Characteristics of Methanogenic Granules Grown on Propionate in an Upflow Anaerobis Sludge Blanket(UASB)Reactor

概要

論文の詳細を見る
Granulation of a propienate-degrading consortia was performed with a mesophilic propionate-acclimatized sludge in an upflow anaerobic sludge blanket(UASB)reactor. The granules formed were relatively small, ranging mainly from 0.3 to 0.6mm in diameter, but had an excellent sedimentation velocity due to a high specific gravity of 1.355g/cm^3(ash content, 48.2%). The ash consisted mainly of calcium(30.2%), phosphorus(19.7%), and magnesium(3.95%)forming plate crystals in the granules. The populations of three bacterial trophic groups present in the granules, propionate-degraders, hydrogenotrophic and aceticlastic methanogens were 5.6×10^8,1.6×10^<10>, and 2×10^9(in most probable number/g mixed-liquor volatile suspended solids[MLVSS]), respectively, while the specific utilization rates of propionate, hydrogen, and acetate of the granules were 9.4,850,and 20.9(mmol/g MLVSS・d), respectively. Electron microscopic analysis showed that Methanothrix spp. appeared dominant over the guanules. Total granular sludge concentration retained in the UASB reactor during 178d of operation was 80.0g mixed-liquor suspended solids(MLSS)/l-reactor, corresponding to 41.4g MLVSS/l-reactor, which realized a high-rate methanogenic fermentation of propionate of 85g chemical oxygen demand(COD)/l-reactor・d.
公益社団法人日本生物工学会の論文
1991-01-25