| Volatile organic compounds（VOCs）are important pollutants that pollute the air environment from many industrial production activities.VOCs emitted from industrial production have the characteristics of continuous,large quantity and low concentration.If they are not treated,they have adverse effects on human health and the safety of ecological environment.Therefore,it is an urgent task to study the terminal treatment technology of VOCs.In recent years,due to the stable physical and chemical properties,non-toxic and high catalytic activity of Ti O2 material,it has been concerned in the photocatalytic oxidation technology.However,the biotrickling filter has the advantages of high porosity,easy control of reaction conditions,small resistance,saving,and environmental friendly,which has gradually become a research hotspot.Therefore,in this paper,the VOCs discharged from the paint soaking section of Tianchang yunchuang electronic factory is treated by a small-scale test system which combines biological trickling filter and photocatalytic oxidation.In this experiment,graphene oxide synthesized from natural graphite powder was used as the precursor of graphene and tetrabutyl titanate as the titanium source to synthesize the graphene titanium dioxide（Ti O2 graphene）composite photocatalysis material.Polypropylene polyhedral ball was used as the filler to carry out the biofilm domestication.The effects of UV lamp wavelength and different external conditions on the efficiency of photocatalytic oxidation,the start-up of bio trickling filter,the most appropriate operating conditions,and the synergistic treatment of VOCs waste gas by photo catalytic oxidation and bio trickling filter were studied.The results show that:（1）In the photocatalytic oxidation system,the removal rate of VOCs by UV lamp with 185nm wavelength is higher than that by UV lamp with 254 nm wavelength.When the reactor is irradiated by UV185 nm light source,the removal rate of VOCs by catalyst reactor is 6.7%higher than that without catalyst.The removal rate of VOCs in the reactor is 100-500 L/h in the range of intake air volume and 50-500 mg/m3 in the range of intake air concentration.（2）In the bio trickling filter system,the activated sludge from the oxidation ditch of the sewage treatment plant with MLSS of 4400 mg/L was used to hang the membrane,and the filler was polypropylene polyhedral ball with diameter of 25 mm.After 21 days of simultaneous acclimation,the treatment of VOCs by bio trickling filter becomes stable and efficient.（3）When the indoor temperature is 15-25℃and the p H of the circulating liquid isbetween 7-8,the optimal residence time and spray rate of the bio trickling filter for VOCs waste gas treatment are 90 s and 250 m L/min respectively,and the removal efficiency of the bio trickling filter for pollutants will decrease with the increase of the air intake concentration.（4）The removal efficiency of VOCs in the biological photocatalytic oxidtion system decreased with the increase of air concentration and air intake.However,the stability or efficiency of VOCs removal is higher than that of single system.The removal rate of VOCs by bio photocatalytic oxidation system is more than 90%in the range of 50～500mg/m3 and 100～600 L/h. |
