Author(s)

B. H. Lee & W. C. Song

Abstract

It is known to be very difficult to treat livestock wastewater because it contains a lot of non-biodegradable organic material. Although many technologies have been employed to treat livestock wastewater such as ozone, AOP, Fenton, and membrane, including various microbiological technologies, they have not been very successful. High concentrations of ozone were applied to treat the livestock wastewater through the DAF (Dissolved Air Flotation) system, so that the DAF system employing ozone was named as the DOF (Dissolved Ozone Flotation) system. Ozone was used to substitute air in the DAF system. A high concentration of ozone provided a high potential of ozone oxidation and a high volume of micro-bubbles. Water quality parameters are removed by the two mechanisms of flotation and ozone oxidation. CODMn was removed partly by flotation and partly by ozone oxidation. An average 81.1% of CODMn was removed from 1,202mg/l to 226mg/l. Suspended solids (SS) and total phosphorus (T-P) were removed mainly by flotation. An average 92% of SS were removed, from 1,504mg/l to 49mg/l. 67.7% of T-N removal was also achieved, from 112mg/l to 32mg/l. 94.6% of T-P was removed by flotation, from 97.81mg/l down to 4.2mg/l. High ozone concentration with microbiological processes made it possible to meet the effluent standards of the livestock wastewater treatment. Keywords: DAF, DOF, livestock wastewater, ozone, oxidation, flotation.

Keywords

DAF, DOF, livestock wastewater, ozone, oxidation, flotation.