Integrated upflow anaerobic sludge blanket and radial-flow aerobic reactors for sewage treatment

Integrated anaerobic/aerobic systems have been considered feasible alternatives concerning technical and economic aspects for treating domestic wastewaters. The main modification in the UASB reactor concerns this association with the RAIB. The UASB effluent was distributed through openings along its side walls to the RAIB, allowing the elimination of collecting channels and feeding devices from the latter reactor. The objective of this work was to promote organic matter (raw and soluble) and nitrogen removal from domestic sewage. Organic matter (as COD) and volatile suspended solids removal achieved efficiencies of 80 % and 89 %, respectively. Under stable operational conditions, the system effluent presented COD and volatile supended solids values of 110 mg·L and 16 mg·L, respectively. Efficiencies of 90 % for COD and volatile suspended solids removal were achieved with a organic loading rate of 4,0 kg COD·m·d.