| In this paper, a study on pharmaceutical waste with hazardous and non-degradation organic compound is carried out by Fenton- biochemical treatment combined process. Fenton oxidation on simulation pharmaceutical wastewater, Fenton oxidation pretreatment and the follow-up biochemical treatment process on the actual pharmaceutical wastewater are carried out in detail; Though the pilot study of combined Fenton- biochemical treatment process on the pollutants degradation of pharmaceutical wastewater, which focuses on the degradation of toxic and harmful substances, we get a series of meaningful results. The research includes:(1)Treatment of simulation pharmaceutical wastewater by Fenton oxidation is carried out. Fenton oxidation of pyridine and DMF wastewater separate experiments show that the influencing factors on treatment effect between the two substances are not the same. And the best value of each factor is differences. The optimum H2O2 concentration, c(H2O2)/c(Fe2+) and response time for Fenton oxidation of pyridine and DMF are varies. Fenton oxidation of simulated wastewater on the same concentration of pyridine requires a higher concentration of H2O2. And it needs a longer reaction time. The same concentration of DMF oxidation need to lower H2O2/Fe2+ molar ratio. The optimal temperature and pH for Fenton oxidation of single pyridine or DMF simulation wastewater is 30℃, pH=3. Kinetic studies show that the Fenton oxidation of simulated pyridine wastewater follows first order kinetics. And DMF wastewater follows the second order kinetics. GC-MS analysis showes that the intermediates generated in the oxidation process of the two substances is more easily biodegradable. Fenton oxidation of pyridine and DMF mixed analog pharmaceutical wastewater shows that, in the Mix system, not only DMF showed good removal efficiency, but also maintain a high removal rate of pyridine. The pretreatment of pyridine and DMF mixed wastewater using Fenton oxidation is feasible.(2)Pretreatment by Fenton oxidation of actual pharmaceutical wastewater showed that: the optimum conditions Fenton oxidation pretreatment pharmaceutical wastewater is: pH=2.5, 30% hydrogen peroxide dosage of 24mL/L, FeSO4?7H2O dosage of 1.5g/L, reaction temperature is 28℃, reaction time 180min. Under optimum conditions, COD removal rate of the wastewater is 35%, and the B/C rate increase to 0.63. Oxygen consumption test by determination of sludge unit shows that the toxicity of waste water reduced greatly, and the biodegradability of waste water is improved significantly. After pretreatment the removal rates of dichloromethane, tetrahydrofuran, pyridine, dimethylformamide, nitrobenzene, o-toluidine wastewater were: 99.1%, 92%, 53.3%, 95.5%, 96.1 %, 99.9%. The results show that the removal of toxic and hazardous refractory organic matte in waste of by the Fenton pretreatment is significantly.(3)Through the comparison test of sludge acclimation synchronous and asynchronous domestication, it is showed that sludge acclimation synchronous is better than asynchronous domesticated domestication on the COD removal rate synchronization, the removal of biodegradable organic matter and time. Acclimation synchronous is more suitable for the wastewater. By the successor biochemical treatment study, we found that system has a strong resistance to impact load, and the effluent can meet emissions standards. Comprehensive analysis shows that Fenton- biochemical treatment Combined Process for pharmaceutical wastewater is stable. And wastewater toxicity can be completely removed. Project results show that, Fenton-biological treatment combined process is stable. And the toxicity of pharmaceutical wastewater can be completely cut. |
