| Title |
Treatment Kinetics of Wastewater and of Morphological Characteristics of Biofilm in Upflow Biobead(R) Process |
| Authors |
염규진 ( Kyu Jin Yum ) ; 이정훈 ( Jeong Hun Lee ) ; 김선미 ( Sun Mi Kim ) ; 최원석 ( Weon Seok Choi ) |
| Abstract |
The objective of this study was to investigate the treatment efficiency, kinetics, and morphological characteristics of biofilm in upflow Biobead^ⓡ process, a kind of biological aerated filter(BAF). The Biobead^?? system showed high removal rates of COD_Mn, (76∼83%), BOD_5(67∼88%) and SS(71∼91%) for food wastewater with high salt concentration (>4,000㎎/ℓ) under short reaction times(2∼3hrs). Even at aerobic condition, the system had high treatment efficiency for both T-N (51∼63%) and T-P(62∼81%). The removal kinetics of COD_Mn, BOD_5, T-N, T-P, and Cl^- in the Biobead^?? system showed a plug-flow pattern with reaction rate constants(hr^-1) of 0.58, 0.63, 0,30, 0.48, and 0.38 respectively. A backwashing process to remove excess biomass and filtered solids was needed at least once during 22-hour operation at 0.5kg BOD m^-3·d^-1 loading. At the higher loading(1.0kg BOD m^-3·d^-1) the backwashing interval was shorten by 8 hours. The COD, BOD, T-N, and T-P were removed from 43 to 66% only by aerobic biodegradation. The SS was removed over 70% by the filtering of Biobead^?? media in the treatment system. The first one of three serial Biobead reactors showed the highest removal values for COD_α(52.3%), COD_Mn(38.8%), BOD(62.5%), and T-N(40.0%). The SS and T-P had the highest removal values(47.5% and 29.2%) at the second one of the serial reactors. The biofilm had non-homogeneous spatial distribution and the colonies were embedded in the sunk area of the Biobead. The thickness of the biofilm was very thin (5.0∼29.4㎛) compared to the biofilm thickness(200∼300㎛) used in other BAF systems |