Removal of oil from produced water by ionic flocculation using saponified babassu coconut oil

Abstract

Oil and gas productions yield a by-product designated as produced water (PW). The high oil content of this effluent prevents its disposal or reuse. This study presents a novel alternative for the removal of oil from produced water using saponified babassu coconut oil (SBCO), as the ionic surfactant part which captures the oil by micellar solubilization, followed by ionic flocculation with Ca2+ ions. A factorial experimental design was applied to optimize the oil removal (RE) process. The experiments investigated the influence of SBCO + CaCl2 concentration, temperature (T), and stirring speed (ω). Extraction Percentages (RE) in the range from 64.901% to 88.444% were achieved. Subsequently, the influence of pH, CaCl2/surfactant ratio and oil removal kinetics in the highest RE% system were evaluated, whereby for pH > 7, (calcium chloride/surfactant) ratio of 1:1, and 15 min of stirring, the RE obtained was 100%. The same maximum removal result was obtained using a microemulsion containing SBCO. Thus, it can be affirmed that the application of ionic flocculation using SBCO is an efficient technique in the treatment of PW.

Keywords

• Oily produced water
• Babassu coconut oil
• Oil recovery
• Wastewaster treatment
• Surfactants