Preparation of a demulsifier for oily wastewater using thorn fir bark as raw materials via a hydrothermal and solvent-free amination route.

ABSTRACT

In current work, a TB-EDA demulsifier for disposing oily wastewater was prepared using thorn fir bark (TB) as starting materials via a hydrothermal and solvent-free amination route. Field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectrometer (EDS), and Fourier transform infrared spectroscope (FT-IR) were employed to characterize the TB-EDA demulsifier. Three-phase contact angle (CA), interfacial activity, formation of interfacial film (FIF), coalescence time of droplets (CTD), dynamic interfacial tension (IFT), and Zeta potential were carried out to study the possible demulsification mechanism. Bottle test was performed to investigate the effect of the TB-EDA dosage, salinity, and pH value on the demulsification performance at room temperature. Light transmittance (DL) and oil removal rate (DR) of separated water were 94.7% and 97.2%, respectively, with 100 mg/L of TB-EDA demulsifier in oily wastewater at room temperature. In addition, the TB-EDA demulsifier has an excellent salt tolerance even at the salinity of 50,000 mg/L. The corresponding DL and DR could reach 99.8% and 99.9%, respectively.