Eur. Phys. J. Appl. Phys. (2013) 61: 24315
https://doi.org/10.1051/epjap/2012120423

Free fatty acids degradation in grease trap purification using ozone bubbling and sonication ^*

¹ Graduate School of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
² Agency of Liaison and Innovation in Saga, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
³ Ohnit Co. Ltd, 3-3-765 Sakuragaoka-Higashi, Akaiwa-shi, Okayama 709-0721, Japan

^a e-mail: yamabec@cc.saga-u.ac.jp

Received: 30 September 2012
Revised: 26 October 2012
Accepted: 6 December 2012
Published online: 15 February 2013

Abstract

The oil and fat were treated at first by only ozone bubbling and it was confirmed that the collection efficiency of them became 98.4% when the aeration was used. It showed that the aeration method in a grease trap cleared the standard value of 90% and there was no worry on the oil and fat outflow from a grease trap. The characteristics of sonication process were studied for free fatty acids degradation. The free saturated fatty acids are the most hard-degradable compounds of the fats, oils and greases (FOGs) in the grease trap. The influence of various parameters such as immersion level of an ultrasound probe in the liquid and bubbling of various gases (Ar, O₂, air, O₃) on the sonochemical and energy efficiency of the sonication process was investigated. The most effective degradation treatment method for saturated free fatty acids was the combination of sonication and low flow rate argon bubbling.