Preparation And Application Research Of New Type Filter Media For Wastewater Treatment

As valuable metallic secondary resource, Blast furnace dust (BFD) has been applied to a certain extent in recent years, but some problems have been existed, such as low comprehensive utilization and industrialization.The dissertation's contents are showed as follows: blast furnace dust was used as main material, new type filter media were preparation. The optimal preparation condition was studied. BFD and ceramics filter media were taken as fillers in Biological Aerated Filter (BAF) to treat beer wastewater, the performance of two kinds of filter media were compared through the contrast experiment.The optimal preparation condition of new type filter media is 150g of blast furnace dust, 15% of clay, 6% of sodium silicate and 600℃of calcination temperature. The influence order of four factors is: BFD addition quantity>calcinations temperature>clay addition quantity>sodium silicate addition quantity.BFD and ceramics filter media were taken as fillers in Biological Aerated Filter (BAF) to treat beer wastewater, the performance of two kinds of filter media were compared through the contrast experiment. On the start-Up of BAF the performance of two kinds of filter media and the removal effects of COD and NH3-N were similar. In same air-water ratio and different hydraulic retention time (HRT), the removal effects of COD and NH₃-N of BAF₂ reactor were better than BAF₁.reactor's, which shows that the performance of BFD filter media was better than ceramics filter media's. In same air-water ratio, the removal effects of COD and NH3-N were better and better with the increase of HRT, but HRT couldn't increase unlimitedly. In same HRT and different air-water ratio, the removal effects of COD and NH3-N of BAF₂ reactor were better than BAF₁.reactor's. In same HRT, the removal effects of COD and NH₃-N were better and better with the increase of air-water ratio.The result of contamination removal orderliness of BAF at different media height showed that COD removal increased fast under the 40cm height but increased slowly at 40-100cm height. At 40-80cm height the removal effect of NH3-N was best, the removal efficiency of NH3-N was 46% in 0-40cm height while that was 90% at the height of 80cm.The removal effect of BAF2 reactor is better than that of BAF₁, which demonstrates that the performance of BFD filter media is better than ceramics filter media. The blust furnace dust filter media have the characteristics of larger specific surface, rougher surface and greater porosity, and therefore are more suitable for growth and reproduction of biofilm.Using blust furnace dust (BFD) filter media as biofilm carrier of Biological Arated Filter (BAF) to treat beer wastewater, the method incarnates the concept of circular economy and explores a new pathway of resources utilization of blast furnace dust.