LABORATORY STUDIES ON THE TEMPERATURE-PHASED ASBR SYSTEM

Treatment of high-strength industrial wastewater with the temperature- phased anaerobic sequencing batch reactor (ASBR) system has shown posi tive results in laboratory scale studies. The system achieved COD remo vals as high as 95% and 90% for soluble and total GOD, respectively, u p to COD loadings of 22 g COD/L/day. Non-fat dry milk was used as a sy nthetic substrate. The system consisted of two reactors operated in se ries at different temperatures. Phase I of the system was operated at 55 degrees C and the Phase II was operated at 35 degrees C, The total hydraulic retention time in the system was 18 hours (6 hours in the Ph ase I and 12 hours in the Phase II). The temperature-phased system inc orporates advantages of both thermophilic treatment (high reaction rat es) and mesophilic treatment (higher quality effluent) while minimizin g the disadvantages such as odors commonly associated with thermophili c treatment and lower treatment rates of mesophilic treatment. This st udy was conducted using ASBRs. The ASBR was developed at Iowa State Un iversity by R.R. Dague. This process allows biomass to increase in the reactors and provides an environment for granulation to occur. Althou gh the ASBR was used for these studies, the temperature-phased process is applicable to other anaerobic treatment processes as well. (C) 199 7 IAWQ. Published by Elsevier Science Ltd.