Synthesis and flocculation of a novel flocculant for treating wastewater produced from polymer flooding

Preparation of a flocculant which can have high-oil removal and no viscous flocs production for treating oily wastewater produced from polymer flooding (OWPF) is meaningful work. In this paper, a novel flocculant (denoted as PDC12DM) for treating OWPF was prepared by copolymerization of dodecyl dimethylallyl ammonium chloride (C12DM) and dimethyl aminopropyl methacryamide (DMAPMA). By using oil removal and viscous floc production as indexes, the synthesis condition of PDC12DM was optimized. The optimum PDC12DM had an oil removal of 98.8% and a viscous floc production decrease of 62.86% compared with commercial cationic flocculant. Measurement of zeta potential, surface tension, interfacial tension, interfacial film strength and dual polarization interferometry tests were carried out for investigating the flocculation mechanism of PDC12DM. The results showed that PDC12DM can destroy oil droplet stability by electrostatic charge neutralization and demulsification together. Especially, demulsification mechanism is helpful for reducing the viscous floc.