Performance of a new equipment for treating domestic wastewater

A fixed-bed aeration reactor system was developed for on-site and small-scale wastewater treatment. The reactor was packed with horizontal plates as support materials. There was no clarifier in the system. Three operational regimes were tested, which were a 6 hours total cycle, 8 hourts total cycle and 12 hours total cycle. Experimental results showed the reactor can treat household wastewater efficiently. Removal efficiencies of BOD and SS were 88% for the BOD loading rate of 0.12 kg/BOD/m³ ·d or 5.2 g/BOD/m²·d. Effluent BOD and SS concentrations were means of 18 mg/l and 6 mg/l during the whole time operation. Suspended solids efficiently sedimented on the horizontal support plates in a short settling time. Equations were developed to predict BOD consumption and sludge production as a function of influent soluble BOD and suspended solids. Useful design and operating parameters are identified for future evaluations of the fixed bed aeration reactor.