Investigation on microwave and ultrasound-assisted cornhusk for the removal of emulsified engine oil from water

Abstract

This study focuses on the removal of synthetically prepared emulsified oil- in-water using raw and reformed/modified cornhusk as an adsorbent via rotary shaker (RS)-, microwave (MW)- and ultrasound (US)-assisted techniques and comparison of adsorption capacity with activated carbon. The chemical modifications were performed using cationic surfactant, cetyl pyridinium chloride solution (CPC, C₂₁H₃₈NCl), on pre-treated sodium hydroxide adsorbent. The binding of surfactant on adsorbent surface is characterized using Fourier transform infra-red spectroscopy analysis and further improvement of impinge surface morphology by scanning electron microscope. The batch studies were performed by varying the influencing process parameters such as contact time, pH, dosage, speed and temperature to confirm the enhanced condition for maximum adsorption capacity. The maximum adsorption capacity of 1,610, 1,566 and 1,698 mg/g has been achieved for MW and US reformed adsorbent and activated carbon. In addition, kinetics first-order, second-order, intra-particle diffusion model and isotherms Langmuir, Freundlich, Dubinin–Radushkevish and Flory–Huggins model data were compared with the experimental data to evaluate the fitness. The error analysis is performed to quantify the coefficient of determination and chi-square values.

Keywords:

• Emulsified oil removal
• Reformed
• Microwave
• Ultrasound
• Error analysis