The investigation on Fe3O4 magnetic flocculation for high efficiency treatment of oily micro-polluted water

Abstract

For the low-concentration oily micro-polluted water formed by the leakage of refined oil products, an unexpensive and high-efficiency magnetic enhanced flocculation method was introduced in this study. First, the performance of magnetic flocculation(MF) to remove oily contaminants was discussed. The results indicated that it achieved more than 95% removal in only 1min with 50mg/L-Polyaluminum chloride(PAC), 50mg/L-Fe3O4 and10mg/L- Polyacrylamide (PAM). The novel indexs Rδand Si were proposed to evaluate the oil removal with UV-Abs in-situ method. According to the adsorption kinetics of oil contaminants, the adsorption kinetics changed from pseudo-first-order to pseudo-second-order kinetics after the addition of Fe3O4 on the basis of conventional coagulation (CF). It was transformed into intraparticle diffusion kinetics when the PAM continued to be added. Combined with the Fe–O–Al bond in the FTIR spectrum of flocs, the main mechanism of MF is enhanced charge neutralization and hydrogen bond adsorption. In addition, it was shown that satisfactory oil removal after recover, which indicated the great potential of a sustainable way by reusing low-cost magnetic seeds.