Organics Removal by Oxidation and Flocculation during Fenton Treatment for Polymeric Wastewater in Dry-spun Acrylic Fiber Production

Fenton method was used for the pretreatment of polymeric wastewater in dry-spun acrylic fiber production. The effects of H₂O₂ dosage, Fe²⁺ dosage, and pH on organics removal were evaluated during the oxidation and flocculation process. The results showed that the total TOC removal efficiency could reach 55.6%, and both oxidation and flocculation processes could achieve high organics removal, when operated under the conditions of H₂O₂ dosage 90.0 mmol/L, Fe²⁺ dosage 30.0 mmol/L, initial pH 3.0, reaction time 120 min and flocculation pH 6.0. The sedimentation of flocs could be advanced in practical application when the flocculation pH was 8.0. Excitation-emission matrix spectroscopy and fluorescence regional integration revealed that most of the protein-like degradable organics were removed during the Fenton process, and the oxidation could hardly remove the fulvic-like organics, which were mainly removed by the flocculation process.