| Over the years,the pattern of air pollution in China has changed greatly.Ozone has appeared in public view many times in the Yangtze River Delta,BeijingTianjin-Hebei and other areas as primary pollutants,which is extremely harmful to the environment and health.China has taken a series of measures including the introduction of VOCs governance policies and standards,elimination of ozone byproduct technology and coordinated control of PM2.5 and ozone.The government only pays attention to the treatment of secondary ozone pollution,but ignores the primary pollution caused by direct ozone emission.China’s ozone concentration rises instead of falling,its annual average concentration has exceeded the secondary atmospheric environmental quality standards.And the season of ozone pollution spreads from summer to late spring and autumn.For ozone governance,which combines complexity and arduousness,it’s urgent to develop an efficient catalytic decomposition agent for ozone discharges.General ozone catalytic decomposition agents have carrier component adsorption properties affected by humidity and high environmental costs,such as high-priced Metal-Organic Frameworks have been used for ozone removal,whose economic efficiency needs to be improved.As a big country in the cultivation and production of sugarcane,our country is rich in waste resources of sugarcane bagasse.The use of sugarcane to prepare biochar can be used as a resource utilization approach to turn waste into treasure and its ozone removal research is rarely reported.Therefore,iron-modified sugarcane biochar and MIL-100(Fe)are used to remove ozone through independent and mixed methods.At the same time,the study also explores the mechanism of ozone removal in both.This study selected sugarcane waste as raw material in Tong’an District,Xiamen City,Fujian Province.The bagasse biochar was prepared by pyrolysis with different temperature gradients and loaded with iron through iron modification to improve the efficiency of ozone removal reaction.The preparation of MIL-100(Fe)adopts a more environmentally friendly hydrothermal synthesis method.The study first carried out a series of symptom tests on sugarcane biochar and MIL-100(Fe).The iron-modified sugarcane biochar and MIL-100(Fe)were tested for ozone removal in a single form and a mixed form of different mass ratios.The ozone removal test concentration is set to 20 ppm,considering the possible ozone escape concentration of ozone denitrification.The study found that the efficiency of ozone removal of sugarcane biochar after iron-modified was higher than before.The biochar modified by ferrous sulfate solution pyrolyzed at 500℃ has the highest ozone removal efficiency,and it can maintain more than 95%ozone removal efficiency within 6 hours of testing.The mass mixing ratio of 10%MIL100(Fe)with 90%biochar is the best,and it maintains more than 97%ozone removal efficiency within 6 hours.The reaction mechanism may be related to functional groups such as oxygen vacancies,aromatic carbon and Fe-O in the material.And the presence of moisture may also affect their ozone removal performance.After evaluating the recycling and economic performance of the material,it is found that the iron-modified sugarcane biochar has good recycling properties and has high ozone removal properties.It still has more than 90%ozone removal efficiency after 4 recyclings.In addition,iron-modified sugarcane biochar is cheap and can be mixed with MIL-100(Fe)materials to significantly reduce its cost.Therefore,iron-modified sugarcane biochar has a broad prospect of development.This study provides some theoretical and laboratory data support for the application of iron-modified sugarcane biochar and MIL-100(Fe)mixtures to the actual production of ozone by-products at the discharge port. |
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