In studying indoor atmospheric pollution,the concentration of air pollutants is considered to be the primary factor in judging indoor pollution level,while sensory effects accessed by olfactory analysis has not been paid enough attention.In this paper,twenty living rooms in Beijing including newly decorated,3 months and 6 months after decoration were sampled once a day for 10 d,and qualitative analysis,quantitative analysis and olfactory analysis of volatile organic compounds were carried out.The results showed the concentrations of the 6 main compounds surpassed the limitation values released by World Health Organization;the pollutants with highest chemical concentrations were not the most odor active odorants.Olfactory analysis which measured the odor characters such as odor detection threshold(ODT),odor active value(OAV) and odor quality was a helpful tool to identify possible chemicals which cause indoor smelling issues,and it was necessary to access indoor air quality in combination with their chemical concentrations to give a comprehensive judgment on indoor air quality.
Baotou RE concentrate was decomposed with concentrated sulfuric acid by controlling the roasting temperature below 500°C.Thermogravimetry-differential thermal analysis(TG-DTA) and chemical analytical methods were used to study the thermal decomposition process and the thermal decomposition effect.The Freeman-Carroll method was applied to analyze the TG-DTA curves.The activation energy, reaction order, and reaction frequency factor at different stages were calculated.The Satava method was used to deduce the reaction mechanism and the relative reaction rate during the thermal decomposition process.
