Abstract
The research and development is concerned with shortening the UASB startup period in the case of seeding digested sewage sludge. The method is to make Methanosarcina nuclear of granules and to promote granulation by adding methanol to wastewater of which dominant carbon source is acetic acid.
Methanosarcina forms pellets easily and settles rapidly.
An nuclear affects the granulation more effectively than loading rate, up-flow velocity and so on. It was confirmed that granulation was progressed by the addition of methanol. When the dosage of methanol is 500mg·l-1, the methanogenic activity of the sludge in the UASB gets 1.4 times higher than that of the sludge without methanol. This means that the addition of methanol contributes to shorten the UASB startup period.
However, were the methanol-sludge load not under 1.5g-methanol.(g-VSS)-1·d-1, acetic acid removal capacity of the sludge would regress.
