Degradation of polyvinyl-alcohol wastewater by Fenton’s reagent: Condition optimization and enhanced biodegradability

Abstract

The pretreatment of refractory polyvinyl-alcohol (PVA) wastewater with low value of COD_Cr by Fenton’s reagent was investigated to enhance the biodegradability. The effects of operating conditions such as pH of the solution, Fe²⁺ dosage, H₂O₂ dosage, reaction time and initial PVA concentration on the removal efficiency of COD_Cr were discussed. It is demonstrated that the optimum value of pH for removal of COD_Cr is 5 and the most suitable dosages of H₂O₂ (2%) and FeSO₄ (10 mg/L) are 5% and 8.0%, respectively. When the initial COD_Cr value of the PVA water is 760 mg/L, the favorable reaction time is 110 min. Under these optimum conditions, the removal ratio of COD_Cr is 58.6%–61.4%, and the value of biodegradability (COD_B/COD_Cr) increases markedly from 8.9%–9.7% to 62.6%–68.3%.

Keywords

Fenton’s reagent / polyvinyl-alcohol / pretreatment / biodegradability