Photo-Fenton processes assisted by solar light used as preliminary step to biological treatment applied to winery wastewaters.

Winery wastewaters are difficult to treat by conventional biological processes, because they are seasonal and experience substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this research work, solar assisted photo-Fenton processes of both heterogeneous and homogeneous phase are used in the pre-treatment of winery wastewaters. The results of these experiments have confirmed the suitability of the photo-Fenton processes, due to these treatments achieving purification levels of up to 50% (measured as total organic carbon). The intermediate effluents are treated adequately by aerobic biological treatment (activated sludge process), due to the decrease in organic matter concentration present in winery wastewaters. The possibility of a combined photo-Fenton process, based on the use of sunlight, and aerobic biological treatment (activated sludge) is suggested.