UASB 공정에 의한 슬러리형 돈사폐수의 처리

초록

This research examined the treatment efficiency and methane production rate in treating slurry-type swine waste using UASB (upflow anaerobic sludge blanket) reactor. The UASB reactor was operated at an organics volumetric loading rate (VLR) of 2.6-15.7 kgCOD/m3/day. A stepwise increase of the VLR resulted in a temporary deterioration in the COD removal rate in UASB reactor but recovered quickly. The COD removal rate were 65-70% for VLR up to 5 kgCOD/m3/day. When organics VLR was 10 kgCOD/m3/day, the COD removal rate decreased sharply and there was loss of 17.537g of the seeding biomass due to sludge washout. This result indicated that the UASB system cannot be adapted to more than 10 kgCOD/m3/day of VLR.As the organic load increased from 2.6 to 15.7 kg COD/m3/d, the biogas production rate varied from 3.2 to 10.8 L/d and the methane conversion rate of the organic matter varied from 0.30 to 0.23 m3CH4/kg CODremoved. The methane content showed the range of 70.1-81.5% during the experimental period. The volatile solids (VS) removal efficiency was similar at the low VLR (< 5 kgCOD/m3/day), but it decreased sharply at the high VLR (> 5 kgCOD/m3/day). The VS reduction rate was, moreover, large those of COD. The result shows that hydraulic retention time above 2 days is essential in case of treating wastewater containing 1% of solids.

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