Wastewater Treatment In A Hybrid Biological Reactor (HBR)

This paper is divided into two parts. The recent progress in wastewater treatment by bilfilm reactor is reviewed in the first part. Hybrid biological reactor (HER), a novel combining process, is concerned. Evaluation methods of biodegradability of various chemicals and methods of treatment of surfactants wastewater are also presented.Experimental studies on hybrid biological reactor are conducted in the second part. A hybrid biological reactor which contained both suspended-and attached-growth biomass is developed by introducing linpor as carriers and used for the treatment of synthetic wastewater and surfactants wastewater.In the first stage, Hybrid biological reactor is used for the treatment of synthetic wastewater in a laboratory scale model. A plexiglass tank with 11.21 effective volume, is used as the aeration. Linpor is placed into the tank. Starting up the reactor after seeding. COD removal efficiency is above 85% as OLR increased to 2kgCOD/m3.d gradually. Compared with conventional activated sludge process (CAS), The Capacity of NH4-N removal and denitrification is better than that in CAS, While COD removal is not as good as in CAS when filled with 25% carriers.In this hybrid biological reactor, attached-growth biomass is about 2g/l, which consisted of above 66% of the total biomass concentration. COD removal efficiency increased with increase of the activity of attached-growth organism. This indicates that the attached-growth biomass and activity played a major role in COD removal in this hybrid biological reactor.Assessments of biodegradability of several important surfactants are tested in the second stage. At 20+1'C, 50mg/l concentration of tween-80 is biodegradable, polyoxyethylene 12-alkyl ether Na^O,, is easily biode- -gradable.Hybrid biological reactor is used for the treatment of tween-80 wastewater in a laboratory scale model in the third stage. At 20℃, HRTllh,about 50mg/l concentration of tween-80 wastewater is treated, COD removal efficiency reaches48.7%.The capacity of NH4-N removal and denitrification in hybrid biological reactor is essential to be studied further. The techniques for high strength surfactants wastewater treatment should be developed.