| People have entered the third pollution period which characteristic was the indoor environmental pollution now, many scientists in the world have started their studies on it, but the studies of that in our country are just beganning. A lot of first-hand information was accumulated by the study of this paper, that made the study of indoor air pollution more systematically and deep, and also obtained a lot of innovative conclusions.Eighteen representative large public places such as shopping malls, supermarkets, furniture stores, theater and railway station’s waiting room were selected and sampled in their different areas or floors, then forteen environmental indicators in these places were detected by instrument method, spectrophotometry, gas chromatography, high performance liquid chromatography and other methods, the indicators are temperature, relative humidity, air velocity, carbon dioxide, ozone, formaldehyde, ammonia, benzene, toluene, xylene, BaP, TVOC, colony number and radon. The distribution of pollution in public places was inferred through comparing and analyzing near 1000 datas, that was the exceeding standard of each indicator was related to the function areas of public places. The changes of physical indicators had no obvious rule. Carbon dioxide, ammonia, formaldehyde, TVOC and BaP were main exceeding standard ones in chemical indicators, and they had their own emission source and rules. The concentration of these indicators was affected by physical indicators such as temperature etal. The exceeding standard rate of biological indicator-total number of colonies was very low. Radioactive indicator-radon didn’t exceed standard.One hundred newly decorated rooms and one hundred non-newly decorated rooms were chosen to collect indoor air(sampling 12 hours later after closing doors and windows). Acetylacetone spectrophotometric method and gas chromatography were used to detect formaldehyde and BTEX in indoor air. Through comparing and analyzing 800 datas of 200 rooms, the result showed that formaldehyde exceeded standard seriously, and its exceeding standard rate was 80%, the highest concentration of formaldehyde exceeded standard nearly ten times. Toluene and xylene were main pollutants in BTEX. The exceeding standard rate of benzene was 2%, so its pollution was not widespread. Toluene’s exceeding standard rate was 10%, and the same to xylene was 23%. The spearman correlation analysis was done by spss13.0 and the result showed that formaldehyde and BTEX in newly decorated rooms were from different sources, but all BTEX were from the same source. Pollution of formaldehyde in non-newly decorated rooms was still serious, its exceeding standard rate was 62%. The exceeding standard rate of benzene was still 2%, and that of toluene and xylene all reduced to 3%, their pollution weakened and inferred that the pollution of BTEX couldn’t last more than several years. One hundred and fifty decorated rooms was chosen to detect TVOC of indoor air with GC-MS, among these rooms, fifty ones have decorated about one week, fifty ones have decorated about one month, and the others have decorated about three months. Analysis result showed that the concentration of TVOC decreased gradually with the time of decorating, its exceeding standard rate reduced to 26% from 68%. There were 59 TVOC components in indoor air of those rooms whose decorated time was more than three months, among them,31 TVOC components could pollute widely, and most of these components were toxic substances. All kinds methods used today to control pollution of indoor air were analysed and detected, and it was found that there was not effective and practical equipment or method to governance pollution of indoor air.Formaldehyde and BTEX’s release rules and influencing factors were researched in climate chamber according to release cycle or release time, it was found that fonnaldehyde in wood panels had similar release rule in different release cycle, its polynomial regression equation of release curves was Y=0.1398+0.02239X-3.89276E-4X2+2.85189E-6X3-7.26359E-9X4. The sources of wood panels had no effect on formaldehyde’s release rule, elevating temperature could speed up formaldehyde’s release rate, humidity’s change had no visible effect on formaldehyde’s release rule, importing of fresh air could change formaldehyde’s release rule temporarily, and the area exposed of plate’s surface had effect on formaldehyde’s release rule, but they did not conform linear relationship. BTEX’s release rule was their concentration lowed gradually with time, the polynomial regression equation of BTEX’s release curves was Y=0.11107+0.00915X-4.92932E-5X2. The difference of decoration materials had no obvious effect on BTEX’s release rule, elevating temperature could speed up BTEX’s release in both periods, humidity’s change had no visible effect on BTEX’s release rule, fresh air could dilute BTEX’s concentration, but it couldn’t shorten the release time.Experimental and theoretical analysis were all used to research some problems, such as the release time of pollutants, the nature of formaldehyde’s releasing and whether it produced secondary pollutants, it was concluded that formaldehyde’s release would last long time, and calculated that the release time of formaldehyde was 16 years at least in a medium decoration room whose area was about 15m2. On the basis of keeping regular ventilating and having no other release source, the release time of BTEX would not be more than one year in a medium decoration room. It was proved that wood panels would release single free-style formaldehyde and composite decomposition type formaldehyde at the same time, but single free-style formaldehyde was main, and it was released not less than 70%. Indoor air was sampled and detected respectively when the room was closed one day, one week and one month by using gas chromatography, it was found that the components and concentration of TVOC all changed, the components of TVOC increased to 50 kinds from 18 kinds, and then reduced to 36 kinds, but there was no formation of secondary pollutants through the whole process. |
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