Effect of addition of Rhodobacter sp. to activated-sludge reactors treating piggery wastewater.
Under aerobic conditions, the decay rates of purple nonsulfur bacteria (Rhodobacter sp.) in the light and dark follow first-order kinetics with rate constants of 0.22 and 0.32 day(-1), respectively. The performance of the conventional activated-sludge reactor (CASR) treating anaerobically pretreated piggery wastewater (656-1.110 mg chemical oxygen demand, COD/L) can be enhanced by the addition of Rhodobacter sp. By performing regressive and statistical analyses using the proposed model and experimental data, the kinetic constants k and Y(T), and the fraction of refractory organic materials (f) of the Rhodobacter sp.-supplemented activated-sludge reactor (RASR) are 40% larger, 21% less, and 34% less than those of the CASR, respectively. From parametric sensitivity analyses, the substrate removal efficiencies of the CASR and RASR are most sensitive to the parameters k and the food to microorganisms ratio (F/M) but least sensitive to the parameter f; the specific oxygen utilization rates of the CASR and RASR are most sensitive to the parameters a and k but least sensitive to the parameter b.
Huang
J S
JS
Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan, ROC. huangjsd@mail.ncku.edu.tw
Wu
C S
CS
Jih
C G
CG
Chen
C T
CT
D000818:Animals; D001421:Bacteria, Anaerobic; D019149:Bioreactors; D007700:Kinetics; D008372:Manure; D016992:Rhodobacter / Q000502:physiology*; D012722:Sewage / Q000382:microbiology*; D013552:Swine; D014865:Waste Disposal, Fluid
D008372:Manure; D012722:Sewage