Research On Bioaugmentation For Simultaneous Desulfurization And Denitrification From Flue Gas By Biofilm-packing Tower

Sulfur dioxide (SO2) and nitrogen oxides (NOx) are the main contaminations from industrial waste gas discharge in China. Once SO2 and NOx emit into the atmosphere, they can lead to the formation of acid rain and photochemistry smoke, being harmful to plants, animals and human health. Since January 1,2016, new version of the environmental air quality standard (GB3095-2012) having been implemented, imposes more stringent regulations on concentration limits of SO2 and NOx pollutants, which implies that purification of SO2 and NOx has become one of the hotspots in the research of air contaminant treatment.In this paper, the SO2 and NOx from the coal-fired power plant flue gas were used as the research object. At the same time, we used the larger and smaller biofilm-packing towers to do our experiments which were studied systematically by using bioaugmentation to enhance the capability of simultaneous desulphurization and denitrogenation.This research was funded by National Natural Science Foundation of China "Application and basic study on strengthening technical methods for simultaneous denitrification and desulfurization from flue gas" (NO.51278447).In the research, a primary study on the feasibility about enhancing capability of biofilm-packing tower using bioaugmentation technique by adding batch compound functional bacterial population on simultaneous desulfurization and denitrification from flue gas was examined. The results indicated that the purification efficiency of NOx from the biofilm-packing tower after adding functional microbial compound was 54.18%, which improved 9.37% than before (44.81%), when the purification efficiency of SO2 from the two towers was steady at 100%. Based on the above experimental results, the effects of inlet concentration of SO2 and NOx in influent gas, gas flow and circulated liquid flow were studied. The results indicated that under the optimum operating conditions that 1500～3000mg/m3 SO2,1300～1500mg/m3 NOx,0.2m3/h gas flow and 9.0L/h liquid flow, the NOx removal rate was improved 17.22% than before (44.81%), reaching 62.03%. However,100% SO2 removal rate was maintained as before. Meanwhile, the variation of main population of nitrification bacteria and denitrification bacteria from the biofilm-packing tower before and after combination was analyzed. And the feasibility of enhancing capability of biofilm-packing tower using bioaugmentation technique by adding special high efficient functional bacterial population on efficiency of flue gas was studied.This work provides a reference of technical basis for technologies development and engineering application in enhancing capability on simultaneous desulfurization and denitrification from flue gas by bioaugmentation technique.