Degradation of Recalcitrant Organics from Winery Wastewater by Fenton's Reaction

Abstract

The advanced treatment of wine vinasses was investigated experimentally using the Fenton reaction. The relationship between the dosage of Fenton reagent and the resulting degradation of residual recalcitrant organics was the main objective of the study. The results indicated that when the dosages of FeSO₄ and H₂O₂ were 450 mg/L and 300 mg/L, respectively, the chemical oxygen demand (COD), biological oxygen demand (BOD₅), and color level were below 250 mg/L, 60 mg/L, and 25 C.U., respectively, at a reaction time of 30 min. Also, the experimental results showed that settling prior to pH adjustment was better than pH adjustment prior to settling after Fenton's reaction. The destruction of the recalcitrant organics in the winery wastewater was effective. The major species of Fenton-treated effluent organics mainly consisted of alcohols and aldehydes. The atomicity variation of the recalcitrant organics was mainly from 10 to 5, and the species was from 20 to 9. This study revealed that the hydroxyl radicals can oxidize almost refractory organics powerfully with only some low weight molecular organics remaining.