Study On Indoor Air Quality Characteristics And Typical Pollutant Degradation Process In Newly Decorated Buildings

Benzene-based pollutants are representative pollutants in newly built buildings.The elimination of such substances is the key to indoor pollution prevention and control.Catalytic oxidation degradation technology is one of the essential technologies to reduce its emissions.Aiming at the defects and shortcomings of traditional catalytic materials,this paper has developed a composite metal porous catalytic material with porous structure,large specific surface area,well-developed pores,and good heat and mass transport performance.This article focuses on studying the catalytic oxidation process of the toluene,revealing the intrinsic relationship between the material’s physicochemical properties and reaction by-products and its catalytic performance.Based on the monolithic composite metal porous catalytic material prepared in the experiment,a new air purifier was developed and designed to solve the current situation of indoor benzene pollutants exceeding the standard.(1)To investigate the current situation of indoor air pollution caused by new decorations in Xi’an,a project was selected for on-site inspection,and the concentration values of five pollutants,such as formaldehyde,benzene,radon,ammonia and TVOC,were analyzed at 42 indoor inspection points.The results show that the concentration of benzene series is relatively large,the concentration of benzene ranges from 0.03g/m~3to 1.01g/m~3,which exceeds the national standard limit;the concentration of formaldehyde ranges from0.03g/m~3to 0.20g/m~3with a small amount of excess;the concentrations of radon,ammonia,and TVOC did not exceed the standard.Therefore,benzene-based pollutants are selected as typical indoor representatives of newly-built buildings to carry out subsequent toluene degradation and catalytic oxidation experiments.In addition,numerical simulation is used to analyze the dissipation state of gaseous pollutants at wind speeds of 0.4m/s and 0.6m/s.The results show that ventilation alone cannot achieve the air dissipation of pollutants,and the need to treat typical indoor pollutants is prominent.(2)Using MOF-74(Mn-Co-Ni)as the precursor porous structure material,the composite metal porous catalytic material Mn Co Ni Ox(MCNO)was synthesized by the rapid pyrolysis method,and the morphology of the mixed metal porous catalytic material was tested.The results show that the composite metal porous catalytic material has a spinel morphology,which has better low-temperature reduction performance and a larger specific surface area than other catalytic oxide materials.And its degradation efficiency of toluene is high,up to 75.7%,much higher than MnOx(27.3%),CoOx(31.9%),NiOx(35.0%).(3)Based on the monolithic composite metal porous catalytic material prepared in the previous experiments,a new air purifier with intelligent temperature control and real-time indoor gas pollutant concentration detection was developed.The hardware consists of MSP430F5438A single-chip microcomputer,SGP30 gas pollutant concentration quality sensor,and DS1820 high-precision temperature sensor,which can realize real-time collection and monitoring of indoor pollutant concentration values.In addition,a prototype of a new type of indoor air purifier was designed and tested in practice.The results show that the new intelligent air purifier can degrade toluene and formaldehyde exceptionally efficiently.