Study on further treatment of Chinese medicine wastewater with Fenton method

Chinese medicine wastewater is a kind of organic wastewater that is hard to be refreshed because of high concentrations of COD with unpredictable fluctuations and low pH value. By ordinary treatment process it is difficult to receive qualified effluent water. Fenton reagent is used in the study of the oxidation and degradation of the effluent water. The oxidation effect is evaluated by the changes of COD and UV₂₅₄ absorbance. The effects of Fenton reagent ratio, dosage of FeSO₄ · 7H₂O, oxidation time, pH value and some other factors on wastewater treatment under normal temperature and pressure are investigated, and the oxidation regularity is initially discovered as well. Orthogonal experiment is applied based on the single factor experiment, as the optimal process condition is determined as follows: the mol ratio of H₂O₂: FeSO₄ is 3:1, the dosage of FeSO₄ · 7H₂O is 3 mmol/L, the pH value is 3, the reaction time is 60 min, Under the said condition, the removal rate of COD reaches 87.50%, and the mass concentration of COD in effluent water decreases to below 62 mg/L, which can meet the state discharge standard.