Influence of the Process Parameters on the Foam Fractionation Treatment of Olive Mill Wastewater

Olive mill wastewater (OMW) is a high organic load waste produced from the three-phase decanter system used in the processing of olives for oil that has phytotoxic and antibacterial phenolic compounds, which makes this waste to resist biological degradation. Foam fractionation has not yet been studied with regard to its potential for treatment of such wastewaters. In the present study, this technique was investigated in a simple model system. The effect of different operational conditions, namely, surfactant concentration, process time, pH and gas flow rate were evaluated in this study. Statistical analysis of the fractional factorial design revealed that the surfactant concentration, pH and the gas flow rate are the most influential process parameters. Low surfactant concentration and pH of 3-4 were found to be advantageous in terms of good chemical oxygen demand (COD) removal. More than 80% of COD was removed through a single stage foam fractionation process. This method has proved to be a feasible technique for the OMW effluent treatment.