Abstract:
As a large coal-producing country,the production of bottom ash is high in China. Although there are many application areas of bottom ash,the amount of bottom application is very limited. In order to improve its utilization,it proposes a new and efficient technology for treating NO in flue gas,achieving the goal of using waste to treat waste. The heterogeneous Fenton catalyst was prepared by alkali modification process,and NO was removed from the fixed bed re- actor. The influence of alkali magnetic modification process on bottom ash was investigated by using X-ray fluorescence spectrometry (XRF),X-ray diffraction (XRD),scanning electron microscopy ( SEM) and Fourier transform infrared spectrometry (FTIR). The effects of reaction temperature,H2 O2 concentration,NO gas concentration and whether SO2 was introduced on the NO removal efficiency were investigated experimentally,and the mechanism of non-homogeneous Fenton removal of NO was analyzed by ESR. The results show that the removal efficiency of NO can reach 86% under the optimal reaction conditions (T = 80 ℃ ,c(H2 O2 )= 6% ,c(NO)= 500×10-6 ,no SO2 ). After the alkaline magnetic modification,the iron content in the bottom ash was obviously improved,which is beneficial to the catalytic reaction.The type of crystal did not change,but the strength of FeOX increased,the strength of quartz decreased,which is favor- able for the catalytic reaction. The surface of the bottom ash became more rough and porous. The internal FeOX was ob- viously exposed,increased the contact area with H2 O2 . The surface favorable functional group content was increased, which is consistent with the experimental results. The reaction temperature,H2 O2 solution concentration,NO concentra- tion and SO2 had a great influence on the removal of NO. The strong oxidation of ·OH radical is the main reason for the removal of NO in Fenton-like system.