Synthesis of an efficient demulsifier derived from cotton cellulose and its demulsification performance in oily...

Substantial amounts of oily wastewater are inevitably generated during petroleum extraction and petrochemical production, and the effective treatment of these O/W emulsions is crucial for environmental protection and resource recovery. The development of an environmentally friendly, cost-effective, and efficient demulsifier that operates effectively at low concentrations remains a significant challenge. This study introduces an eco-friendly ionic liquid demulsifier, Cotton Cellulose-Dodecylamine (CCDA), which demonstrates exceptional demulsification performance at low concentrations. CCDA was synthesized from natural cotton, which underwent hydrophobic modification using dodecylamine. The chemical structure and surface morphology were characterized using FT-IR, ¹H NMR, ¹³C NMR and SEM. The demulsification experiments demonstrated that CCDA-6 achieved a light transmittance of 87.56 % and an oil removal rate of 99.78 % at 20 mg/L, along with exceptional salt tolerance. Besides, CCDA-6 exhibited effective demulsification in O/W emulsions stabilized by anionic and nonionic surfactants. Furthermore, the possible demulsification mechanism of CCDA-6 was elucidated through an analysis of interfacial adsorption kinetics and zeta potential measurements. The results indicate that CCDA-6 promotes demulsification by replacing natural surfactants at the interface and facilitating electrostatic neutralization. Consequently, CCDA-6 holds significant promise for the treatment of oily wastewater and provides a new idea for the application of biomass materials in demulsification.