permanent magnets and the other one without. Experimental setup of the biodegradation process is shown inFig. 1.
After biodegradation, liquid samples (10 mL from each flask)
were collected and centrifuged at 4000 rpm for 15 min, and then
the supernatant fluid was analyzed for residual concentrations of
COD. Experiments were repeated at least 3 times exactly in identical conditions and the average values were used in calculations.
It is worth mentioning that the bacteria acclimated in the magnetic field of induction 20.0 mT were used when biodegradation
experiments were carried out to investigate the effects of magnetic
field induction, temperature and initial pH. With respect to the
determination of the biodegradation time, biodegradation experiments were performed in four different conditions (Table 3)