Abstract:acteristics of high viscosity, high color, strong odor and high organic content, the process of "iron-car⁃bon micro-electrolysis + Fenton oxidation + coagulation precipitation" was developed. The resultsshowed that when the pH was 2 and the reaction time was 2 h, the removal rate of CODCrcould reach54.5%. In Fenton process, when the H2O2dosage was 1.0%, and reaction time was 2 h, the removalrate of CODCrcould reached 55.8%. Coagulation and precipitation process further improved the removaleffect of CODCr. The total removal rate of CODCrby the combined pretreatment process was 88.9%, en⁃suring that the effluent CODCrconcentration was less than 3 000 mg/L, and the biodegradability ofwastewater was increased from 0.12 to 0.32. Close-