Study On No Removal Capability With Gas-liquid Two-phase Mixing Flow In Rotating Drum Biofilter

Nitrogen oxides?NO_x?are one of the main pollutants which cause a series of serious air pollution such as acid rain,photochemical smog and so on.In many areas of China,the pollution of NO is worsening and the coastal part of the developed areas of industrial air pollution is more serious.Currently,the country has been increasing emphasis on the control of nitrogen oxides and nitrogen oxides emission standards are more stringent.In 2020 and 2030,NOx emissions will reach about 23.63³1.54million ton and 29.14⁴2.96 million ton,surpassing the US as the world's largest NOx emissions.NOx control task is particularly urgent.The experiment using the improvement of RDB reactor,is on the basis of the previous experimental study which mainly remove NO in simulated flue gas pollutants and we investigate the denitrification performance of RDB dealing with flue gas,and explore the effect of the gas phase NO and liquid phase Fe^II?EDTA?in a mixed flow on the pass mass.Experimental results show that after experiencing sludge domestication and early stages of biofilm formation,NO removal efficiency of RDB reactor is good on condition that simulated flue gas is at a flow rate of 8 L min^-1,EBRT is 1.5 min,flow rate of the nutrient solution is 20 mL min^-1,the oxygen concentration is 2%.When the biofilm is completed,NO removal efficiency can reach 80.1%.In the continuous and stable operation time of 135 d,the initial NO concentration was between 154.8¹339.3 mg m^-3,NO removal efficiency and NO elimination capacity are35.1%⁹9.1%and 5.24³0.81 mg m^-33 h^-1,respectively.The average of NO removal efficiency was 67.1%,and the average of NO elimination capacity was 18.02 mg m^-33 h^-1.At the same time,the generation of N₂O is between2.64⁵3.79 mg m^-3,and the average amount of N₂O is 28.22 mg m^-3.The concentration of inlet NO determines the elimination capacity of RDB,and the maximum elimination capacity of the reactor was 31.5 g m^-3h^-1.The changes of nutrition liquid back flow rate and the speed of RDB have an impact on the growth of drum membrane microorganism and the nutrient solution update rate.It determines whether the growth of the inner drum filler biofilm is uniform.The maximum of NO removal efficiency appears at the speed of 0.8 r min^-1.At the same time,the moderate amount of N₂O production is only 13.8 mg m^-3.Empty bed residence time?EBRT?not only affects the NO removal,but also has an effect on NO elimination capacity.When glucose is used as carbon source,the growth of microbial is optimum,the denitrification efficiency is the best,and the generation of N₂O is less.Sodium acetate and ethanol are closer when they are used as carbon source,methanol is the worst because of its toxic.The big concentration of oxygen will inhibit the process of denitrification,and it will also increase the oxidation of Fe²⁺,resulting in a serious decline of NO removal efficiency.