Computational fluid dynamics and factor analysis of a novel swirling demulsified airlift loop reactor for the treatment of refined soybean oil wastewater.

A swirling demulsified airlift loop reactor (SD-ALR) was developed for the treatment of oily wastewater with yeasts. Computational fluid dynamics simulations showed that the gas holdup and liquid velocity gradient in the SD-ALR were 2.9% and 0.37 m/s higher than those in the traditional airlift loop reactor. The optimization results of the swirling demulsifier showed that the optimal number and elevation angle of the blades were 8 and 45°, and the optimal installation position was 150 mm from the bottom of the draft tube. The results of treating refined soybean oil wastewater in the SD-ALR showed that the wastewater treatment time was decreased by 8 h, and the removals of chemical oxygen demand and oil content increased by 5.10% ± 0.02% and 9.55% ± 0.40%, respectively, compared with those in the traditional airlift loop reactor. A volumetric mass transfer coefficient model was established for SD-ALR and oily wastewater.