Diatomite Precoat Filtration For Wastewater And Recycling

The amount of urban wastewater emission has increased from 22.77 billion tons in 2001 to 53.52 billion tons in 2015,and the investment of urban environmental infrastructure has increased from 59.57 billion yuan to 494.68 billion yuan.Such a huge amount of emission and governance investment require us to constantly improve and optimize the wastewater treatment process and save wastewater treatment investment on the basis of satisfying the requirements of sewage governance.The approaches of model experiment,Computational Fluid Dynamics(CFD)simulation and gas flow acceleration classification and drying were adopted,filtration performance and the fouling mechanism were studied during precoat filtration,the characteristics of precoat filtration was further revealed from the perspective of simulation,the filter cake obtained from the precoat filtration was classified and dried creatively.The following major research progress has been achieved:(1)The precoat filtration performance was investigated in this study,and the optimum coating thickness was 4 mm.The main pollution mechanisms that occurred in different time periods were recognized through segmented fitting of the Hermia fouling model.The pollutant transport was revealed from a spatial perspective by detecting surface enhanced Raman spectroscopy.(2)The pressure loss of the precoat filter increased with the precoating layer thickening,and the larger the precoating thickness,the larger the increase gradient;as for the filter efficiency,the filtration efficiency with precoating first increased rapidly until the coating layer thickness is greater than 4 mm,the filtration efficiency does not change significantly.(3)After precoat filter cake being disposed,the water removal effect was obvious,the material morphology changed from initial agglomerate to disperse,and there was a significant color difference between particles at the upper and lower outlet after classification.The optimal operating temperature was chosen to be 210?,the optimal gas flow rate was 85 m3/h,and the optimal feed rate was 0.8 kg/h.The awareness level of the precoat filtration process was raised,an integrated airflow acceleration classification and drying device was proposed,which guides the design and optimization of the sewage treatment process in practical applications and provides new ideas for industrial applications as a transformative technology.