Study Of Biological Aerated Filter (BAF) Used For Urea Containing Wastewater Treatment

At present, pollution and shortage of water have become serious problems that affect development of society and economy greatly, and eutrophication constitutes a considerable menace to aquatic environment. The contamination of Ammonia-nitrogen in water mainly comes from the chemical fertilizer industry discharged. There is no matured treatment technology for high ammonia wastewater which brings by the production of urea, so the research of ammonia treatment technology is very important. In this research the simulated urea containing wastewater treatment is used by the biological aerated filter to study start-up rule, treatment efficiency, effect factor, and the optimizing operation parameters are obtained. All these results have great theoretic and engineering meanings for the BAF technology is used to treat the high ammonia wastewater. During the test of the active sludge culture domestication and film formation in Biological Aerated Filter (BAF) to treat the wastewater containing urea, the urea removal rate and the characteristics of microorganism are analyzed; the conversion regulation of the chemical element of Nitrogen is discussed in BAF. The experiment adopts the method of compound start-up with inoculums, which domesticates firstly, then start-up of the bioreactor. The removal efficiency of urea reaches over 85% in twelve days from the start-up, which demonstrates the form-film of the system is succeeded.The study results show the average remove rate of urea,CODCr,Urea-N+NH3-N are 89.5%,85%,55.3%. The BAF can stand impacting load to some extend. The removal effect of the Urea-N+NH₃-N gradually moves up in the test, and the remove rate reaches 90.2%. The pollution removal efficiency changes with the height of the BAF, most biofilm develops and most urea is removed in the range of 0²0cm from the inlet.Furthermore, the experiment investigates effect factors on the treatment efficiency of BAF such as hydraulic load, loading rate, influent temperature and influent pH, accordingly optimize the running conditions of the reactor. It is the optimum hydraulic load for contaminant remove when it is 0.4m³/(m²Â·h). The...