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Electromagnetic field with ac frequency conversion has a character which can changethe internal energy of materials in the system, PFS is widely used in coagulation processes,and it contains ferromagnetic materials which are sensitive to magnetic field. Moreover,we found that magnetized PFS solution had a better effect in coagulation experiments.Therefore, in this paper, a bench test on cooperation of PFS and electromagnetic field wascarried out at room temperature. We magnetized PFS solution for experiments by a self-designed electromagnetic device with ac frequency conversion, to zeta potential, particlesize, conductivity of PFS solution and coagulation effluent residual turbidity, CODCr,sludge moisture content, volume of sludge and SRF as indicators, we studied theinfluences of electromagnetic field with ac frequency conversion by single factor andorthogonal coagulation experiments. Comprehensive analyzed the effects ofelectromagnetic field on the coagulation property of PFS, and verified the theories by thedistribution water with kaolin. At the same time, it was also a basis for the actualcoagulation treatment. At last, we applied magnetized PFS solution to the coagulation ofYellow river.Compared with conventional PFS, the zeta potential of magnetized PFS increased to17.2mV by13mV, partical size increased to372.8d.nm by300.2d.nm, conductivityincreased to5.04mS/cm by4.68mS/cm. The best levels as follows: concentration of PFS-2%, voltage-100V, frequency-150and300Hz, current-0.7A, magnetized time-40seconds. After PFS solution stood at0.5h, the coagulation effects of PFS were good; thestability of magnetized PFS improved27%, and magnetization effects can be kept at2.5h.Distribution water with kaolin test accurately verified zeta potential, particle size andconductivity of PFS.The dosage of magnetized PFS was saved to60mg/L under theoptimal condition mentioned above. Effluent turbidity NTU reduced from3.7to2.2NTU.When we runed off coagulation treatment, adding magnetized PFS, the residualturbidity and water CODCrreduced from3.18NTU,35mg/L to0.75NTU,24mg/L, dosage of PFS reduced from140mg/L to80mg/L, sludge settling time reduced from10min to5min, volume reduced from65ml to42ml, and SRF reduced from0.53×10~9s~2/gto0.32×10~9s~2/g, the generation of floc structure compacts were low moisture content andsmall size.Comprehensive coagulation test results, the optimization conditions for thecoagulation process: dosage of PFS-80mg/L, voltage-100V, frequency-150Hz, current-0.7A, magnetized time-60seconds.
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