Zeolite fly ash-enhanced coagulation treatment of oil recovery wastewater from polymer flooding

Herein, an enhanced coagulation model is proposed in which zeolite is used as a crystal nucleus to promote flocs. The zeolite is prepared from fly ash by microwave-assisted hydrothermal synthesis. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and specific surface area and pore size analysis (BET) characterization confirmed the successful synthesis of ZFA, and improved the surface properties. Thus, the adsorption capacity of ZFA as crystal nucleus was improved, which enabled it to achieve better results in the process of enhanced coagulation. Compared with those of conventional coagulation, the oil content and SS removal rate of ZFA-enhanced coagulation increased by 85% and 44%, respectively. Compared with that of CFA-enhanced coagulation, the oil removal efficiency increased by 4%, and the SS removal efficiency increased by 9%. The optimal conditions of ZFA-enhanced coagulation were as follows: ZFA dosage of 100 mg/L, pH value of 5-8, ZFA particle size range of 60-75 mu m, temperature of 40-50 celcius, and precipitation time of 30 min.

Automated summary

This study proposes an enhanced coagulation model using zeolite as a crystal nucleus to promote flocs. Zeolite is prepared from fly ash by microwave-assisted hydrothermal synthesis and characterized using SEM, XRD, BET analysis. The results show improved surface properties and adsorption capacity of ZFA as a crystal nucleus, leading to higher oil content and SS removal rate compared to conventional coagulation. The optimal conditions for ZFA-enhanced coagulation are identified.