Application Of Two Advanced Oxidation Technologies In The Treatment Of Deinking Effluent

In recent years, with the increase of reuse of the wastepaper, the deinking effluent has become a new pollution source in the process of paper making. Studies of advanced oxidation processes during recent years have shown that the methods are very promising in waste water treatment and have received increasing attentions. In this thesis,coagulation,Fenton reagent,ultrasound/Fenton reagent technology and microwave irradiation/Fenton technology are applied to the treatment of deinking effluent. Results are as follows:It is feasible to pretreat the deinking effluent by using PAC and PAM. The COD of the original deinking effluent is 2000mg/L.The removal efficiency of the effluent is 79.6% after coagulation. The COD removal efficiency of the pretreated effluent is 59.0% by Fenton reagent and is 80.5% by ultrasound/Fenton reagent technology.Results showed that: the degradation effect of COD by ultrasound /Fenton reagent method had an obvious synergistic effect. The result is better than the simple summation of Fenton reagent method and ultrasound method. The optimal conditions are as follows:H2O2 and Fe2+ dosage both 250mg/L,pH 3,reaction temperature 50℃,the ultrasound intensity 12W/cm2,reaction time 30min.The methods of catalytic wet oxidation under microwave radiation and catalytic wet oxidation under microwave radiation-Fenton reagent technology were both effective for the removal of COD of the effluent after coagulation. But the later was better. The optimal conditions of the later method are as follows(for 100ml effluent): activated carbon dosage 0.3g,H2O2 and Fe2+ dosage both 150mg/L,pH 3,reaction temperature 60℃,microwave irradiation time 24min,the removal efficiency of COD is 82.4% under the optimal conditions. The regeneration of activated carbon is studied,using the removal efficiency of COD as reference,the times of regeneration are at least 10 without obvious reduction of the removal efficiency.Optimization experiment and kinetics experiment were also conducted in this thesis. Results showed that these reactions were all first-order. GC-MS was used to monitor the organic substances in the effluent before and after treatment, the degradation effect was further validated.The main contaminations of waste water after treatment by ultrasound/Fenton reagent technology and catalytic wet oxidation under microwave radiation/Fenton reagent technology both satisfy the Nation Water Quality 1 of integrated Wastewater Discharging Standard. Part of the waste water after treatment can be reused. Both of the methods provide a new technique for the treatment of the deinking effluent and for the zero discharge of wastewater in deinking industry.