DEVELOPMENT OF A NOVEL SEWAGE TREATMENT TECHNOLOGY WITH MINIMUM ENERGY REQUIREMENT

−PERFORMANCE OF ORGANIC MATTERS REMOVAL BY PRACTICAL-SCALE DHS REACTOR−

Abstract

A novel aerobic process with no external aeration input, called Down-flow Hanging Sponge (DHS) reactor was developed for polish-up of the effluent from UASB reactor treating a municipal sewage. Process performance of DHS with respect to organic matter was evaluated by a long-term (900 days) nonstop operation of a practical-scale plant. The DHS was fed daily 500m³ of the UASB effluent at 1.5h HRT on the basis of sponge volume. The final effluent from DHS showed superior quality, i.e., 6 mg/L for BOD and 8 mg/L for SS, respectively. Observed sludge yield of the DHS was calculated to be 0.05 kgSS/kgCOD-removed, which is extremely less than that of other aerobic systems employed for post treatment of UASB treating sewage. These results demonstrate that our proposed system successfully achieved an excellent performance that is almost equivalent to that of conventional activated sludge process.