Influence of magnetic field on the kinetics of activated sludge

This investigation was performed as a background study for magnetically stabilized fluidized bed biofilm reactors for wastewater treatment. The aim of this study is to show the influence of magnetic field application on microbial growth and to use a simplified method in batch wise study to determine this influence on the biological kinetic parameters. The kinetic parameters of mu(max), K(s), Y(x/s) and m of the activated sludge on glucose removal as a model substrate for wastewater treatment were determined in a simple way by using the data of only one batch experiment at a definite condition. At the same condition, instead of the difficult, expensive and time consuming several continuous steady state studies with different influent substrate concentrations the results of only one batch experiment of two identical reactors, one with and the other without magnetic field application, could be enough for the evaluation. It was found that kinetic parameters were changing with magnetic field strengths of 8.9, 17.8, 24.4, 36.6 and 46.6 mT and 17.8 mT is the optimum strength for biological glucose removal under the studied conditions. While mu(max) and m are increasing with the application of optimum magnetic field strength of 17.8 mT, K(s) and Y(x/s) are decreasing implying that average affinity of microorganisms present in activated sludge to the substrate and their growth rates are increasing but a smaller amount of sludge corresponding to the amount of substrate removal was produced with the application of magnetic field. This result shows an improvement in the treatment efficiency by the application of magnetic field.