Iron compounds and a magnetic field as the conditioning agents for municipal sewage sludge

The purpose of the research was to determine the possibility of using a magnetic field as a factor supporting the conditioning of municipal sewage sludge prepared using a chemical method. In order to condition the sludge, PIX 113 iron coagulant or Fe3O4 nanoparticles were used. Two types of organic flocculants: medium cationic Superfloc ® C-494 and high cationic Superfloc ® C-496 were also applied. For the various test combinations a capillary suction time test was performed, the specific resistance to filtration and the final filtration of the filter cakes were determined. For selected combinations, a quality of supernatants analysis was also performed, the measure of which was the COD values. The results show, that in the dual chemical conditioning method, the use of PIX 113 coagulant was more favorable than the nanoparticles Fe3O4. The influence of a magnetic field on the susceptibility to the dewatering of the tested sludge was variable, depending on process parameters such as the flow direction and flow rate through the solenoid. The type of polyelectrolyte used in the conditioning method with magnetic field action was also significant.