The Studies Of On Domestic Wastewater Treated By Three-phase Inner Loop Biological Fluidized Bed Process

Three-phase inner loop biological fluidized bed is a new biological treatment technology in wastewater, which intergrates conventional chemical engineering fluidized technique and immobilized microorganism. It is the most efficient one in the field of the domestic wastewater treatment. The reasons of its efficiency lie in two aspects: firstly, it is due to the high biomass concentration brought by the immobilization of microbe on the particle carriers (called bio-parties).So the bio-reaction rate and process stability can be improved. Secondly, it is due to the high diffusion coefficient between the substrate and microbe by fluidization of the bio-particles.Three-phase biological fluidized bed which made by myself is used to dispose organic pollutant of domestic wastewater and nitrogen. The main work of the dissertation includes three experiments: the start-up of the biological fluidized bed; the studies on domestic wastewater treated by three-phase inner loop biological fluidized bed process; the study of bio-denitrification on domestic wastewater treated by anoxic tank - three-phase inner loop biological fluidized bed process.The results show that:(1) Activated Carbon as a carrier of the inner loop three-phase biological fluidized bed, using an improved rapid mud hang Biofilm is fast, the biofilm on the activated Carbon is rich. In the hanging film process, the hydraulic residence time and aeration directly related to the biofilm.Hydraulic retention time which is less than 4h is conducive to biofilm formation, aeration excessive or too low is not conducive to biofilm formation.(2) using three-phase circulating fluidized bed biological treatment of domestic sewage, when the hydraulic retention time of 140min, aeration volume 5L/min, COD, ammonia nitrogen, SS removal rate, respectively, between reach 87.9%-89.3%,65.8%-70.6%,88.5%-92.0%,meeting wastewater discharge standards GB18918 -2002 1 B emission standards.(3) Denitrification test with anoxic tank - three-phase circulating fluidized bed treating domestic sewage showed that within a certain range increasing the reflux ratio is conducive to total nitrogen removal process, and increasing the reflux ratio is conducive to organic matter, water quality is good.