Treatment Of DDNP Wastewater With Coagulation-fenton Process Andwhite Rot Fungi

DDNP wastewater in a certain chemical factory was taken in the paper, the merit and demerit of currently technics used to treat DDNP wastewater was summarized on the basis of fully understanding the process of DDNP industy and the characteristics of DDNP wastewater. Furthermore the mechanism of coagulation experiments and Fenton oxidation are analysed. The treatment of DDNP wastewater by the coagulation,the Fenton and the coagulation- Fenton process and white rot fungus were investigated.1,In the paper, the coagulation,the Fenton and the coagulation- Fenton process were used to treatment DDNP wastewater. The effect of the dosage of PAC, the pH value, the coagulation time, the dosage of H2O2 and the dosage of FeSO4·7H2O and other factors on the water treatment were investigated by means of the removal rate of COD and that of color , the reaction conditions were optimized through orthogonal experiments. Single-factor experiments were used to verify the optimum reaction conditions. The conclusion was as follows:(1)The optimum conditions of coagulation were as follows: under normal temperature , the pH value was 6.0, the dosage of PAC was 7.5g/L, the coagulation time was 4 h, the removal rate of COD was 50.96%, the removal rate of color was 80%.(2)The results of Fenton show that when the pH value was 4.0, the dosage of H2O2 was 40ml/L, the dosage of FeSO4·7H2O was 2.502g/L and the reaction time was 4 h under normal temperature, the COD of DDNP wastewater after the treatment was 1386 mg/L, the removal rate of COD was 66.68%; the color of DDNP wastewater declined to 2700 times, the removal rate of color was 89.20%.(3)The optimum conditions of coagulation-Fenton process were as follows: for coagulation, the pH value was 6.0,the dosage of PAC was 7.5g/L,coagulant time was 4h;for Fenton reagent oxidation,the pH value was 5.0,the dosage of H2O2 was 20ml/L,the dosage of FeSO4·7H2O was 3.336g/L, the reaction time was 2h. Under this condition, the total removal rate of COD was 81.72%, the total removal rate of color was 92.80%.2,The biodegradation of DDNP wastewater by white rot fungus was investigated primarily.The results shown that white rot fungus could remove COD in DDNP wastewater,the removal rate of COD was 68.25%, the removal rate of color was 92%.