Wastewater treatment in sewer systems with biofilms

Removal of pollutants in sewer lines by attached growth microorganisms may be considered as a new method. Investigations have been carried out by considering conduits as a biological reactor. A sewage circulating reactor where slope and wastewater velocity can be adjusted was set up. Packing material was placed in the channel to increase biofilm area. Biofilm was grown on the inner surface and on the packing material. The model was fed by glucose based synthetic wastewater and parameters related to organic content, nitrification and other pollutants were monitored. Around 90% TOC and 77-87% TSS removal efficiencies were attained after 7 hour circulation. Whereas, 33-64% total nitrogen reduction were obtained following to 24 hour circulation.