Abstract
Excess activated sludge is a serious problem in waste water treatment plants (WWTPs). Several methods have been introduced to reduce the growth of excess activated sludge; however, an effective method remains to be discovered. We have developed a method that uses the motion of ferrite particles to treat the excess activated sludge produced in WWTPs. The motion of ferrite particles was controlled by two electromagnets (EMs). A magnetic circuit with two metal plates between the EMs was proposed, so that the magnetic flux of the magnets can be obtained for a larger area. Thus, a larger container with activated sludge can be treated, and by applying an AC voltage, it can be sterilized and its quantity can be reduced. We discussed the relations between the magnetic flux distribution and the width of the metal plates. Moreover, we succeeded in reducing excess activated sludge for various concentrations of activated sludge (i.e., 2000mg/L, 4000mg/L, and 6000mg/L). Our experiments show promising prospects for the use of magnetoferrite treatment in the return line of activated sludge in sewerage plants.
