Thermal hydrolysis of secondary scum for control of biological foam.
Thermal hydrolysis of secondary scum at 9 bars and 170 degrees C was shown to completely destroy Gordonia sp. cells and reduce its foaming potential, so that it can be recycled to headworks or sent to the solids-handling side of the plant without the risk of causing foaming problems in the activated sludge system and anaerobic digesters. This process shows promise for biological foam control in wastewater treatment plants where solids retention time control and selective wasting cannot be applied and/or selector installation is not possible. An initial cost comparison of thermal hydrolysis and several widely accepted foam-management strategies shows it to be competitive; however, optimization of operating pressure and temperature is necessary.
Jolis
Domènec
D
Wastewater Enterprise of the San Francisco Public Utilities Commission, California, USA. djolis@sfwater.org
Marneri
Matina
M
D000693:Anaerobiosis; D019149:Bioreactors / Q000382:microbiology; D005240:Feasibility Studies; D005427:Flocculation; D033601:Gordonia Bacterium / Q000254:growth & development / Q000378:metabolism; D006868:Hydrolysis; D017404:In Situ Hybridization, Fluorescence; D008954:Models, Biological; D012722:Sewage / Q000382:microbiology; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000191:economics / Q000295:instrumentation / Q000379:methods*
D012722:Sewage