Abstract: Fly ash was modified by microwave acid activation method.The oxidation of Fenton reagent and the adsorption of modified fly ash were combined to treat the coking wastewater.Some important affecting factors were discussed in the Fenton oxidation and modified fly ash absorption processes. Experiment results showed that the COD removal ratio of coking waste- water reached 92% after 120 min of absorption time and the dosage of 30 g/L modified ash fly under the optimized Fenton oxidation conditions，i.e.，initial pH=3，reaction temperature was 60 ℃，concentration of H₂O₂ was 100 mmol/L，and mass concentration of Fe²⁺ was 0.4 g/L.

Key words: Fenton reagent, microwave acid activation, fly ash, coking wastewater