Abstract:Effluent from secondary biological process for papermaking wastewater was employed as the model pollutants. Under the optimum conditions of the initial pH: 4, pyrite adding dosage: 1 g·L-1, H2O2 adding dosage: 50.0 mg·L-1, and the oxidation reaction time: 1 h, chemical oxygen demand (COD) of wastewater can decrease from 136.0 mg·L-1 to 44.8 mg·L-1. The pyrite is found to be active to promote Fenton like reaction with low cost due to high utilization efficiency of H2O2, furthermore, catalyst can be easily recovered from wastewater and reused.