Joint treatment of wastewater from table olive processing and urban wastewater. Integrated ozonation - aerobic oxidation

Integrated ozonation-aerobic biodegradation of table olive wastewater (diluted 1:25 with synthetic urban wastewater) is presented as a suitable technology to purify this kind of effluent. Use of ozone is recommended as a pre-treatment step since it shows a high reactivity toward phenolic compounds (found in this type of wastewater) reducing, at the same time, the alkalinity of the media for further biological processing. An ozone dose of 45 mg L-1 (flow rate 20 L h-1) for a period of 35 min has been found to achieve the following goals: decrease pH, decrease phenolic content, and increase of biodegradability. The aerobic oxidation process followed first order kinetics as measured by COD depletion profiles versus time. The Arrhenius expression k = 183exp(-2214/T) was obtained for experiments of ozonated wastewater biodegradation completed at different temperatures and neutral pH.