Applicability of ozonized water treatment for controlling fat, oil, and grease deposition onto a drainpipe

The fat, oil, and grease (FOG) deposition onto pipes is a serious problem in wastewater management, especially in restaurants that have a limited space and no expert for water treatment. In this research effects of ozonized water treatment on controlling FOG deposition were discussed using lard as a model FOG deposit. Since ozonized water can be produced from tap water with an electrolysis ozonized water generator, ozonized water treatment has a potential to be a compact and easily operable process. A series of batch tests with 24-hours contact time revealed that ozonized water successfully prevented liquid lard from solidifying and enhanced the elution of solid lard. Both functions were proportionally intensified with the increase in ozone consumption. An intermittent ozonized-water flushing with 200-seconds contact time using a model drainpipe, whose inner wall was covered with solid lard, was also effective in removing lard from the drainpipe with the linear relationship between the lard elution and the ozone consumption. The observed ratio of the cumulative mass of eluted lard to the cumulative ozone consumption was 1.15±0.04 mgC/mgO3. Thus, the intermittent flushing of drainpipe with ozonized water was inferred to be an effective option for controlling FOG deposition.