Abstract: The HNO₃/H₂O₂ oxidation absorption solution is used to denitrate the simulated flue gas containing NO_x, and the absorption solution after denitration is used as the nitrogen source for microalgae cultivation. The effects of different heights of the packing on the denitration of flue gas, the contents metal ions in flue gas, trace elements in the microalgae medium and pH of the medium on the decomposition rate of H₂O₂ in the absorption solution were investigated to explore the feasibility of using HNO₃/H₂O₂ as a nitrogen source for the growth of Chlorella pyrenoidosa. The results show that the addition of packing in the absorption column can strengthen the gas-liquid contact and effectively reduce the liquid-gas volume ratio under the premise of ensuring a certain denitration rate. The iron, cobalt, and nickel ions in the flue gas can easily cause the decomposition of H₂O₂. The microalgae medium containing trace elements and weakly acidic environment are conducive to the decomposition of H₂O₂. The growth rate of Chlorella pyrenoidosa is higher when HNO₃ is used as the nitrogen source than that of NaNO₃, and the growth of microalgae is not affected when there is a small amount of H₂O₂ in the absorption solution of nitrogen source.

Key words: nitrate, peroxide, denitration, microalgae