Carrying Components Analysis And Purification Efficient Of Particulate Matter In Environmental Tobacco Smoke

Environmental tobacco smoke (ETS) cause serious harm human health, and it has been confirmed to be connected with the diseases of aspiratory system and cardiovascular system. From the following three aspects, this paper carried out a series of experiments to study on the component carried on particulate matter (PM) and the purification of the PM.Firstly, carrying components on particulate matter released from cigarette burning were analyzed. The PM released from cigarette burning was collected separately using Anderson sampler, which may be divided into eight diameter segments. Organic carbon and elemental carbon (OC/EC),25 elements, and 5 ions on particulate matter were analyzed. The results showed that:The total mass of carbon is about 20%-23%of the total mass of particulate matter, and more than 90% of the total carbon is organic carbon. Compared with coal dust and fuel dust, PM released from cigarette burning was more toxic because of higher content of organic carbon. The top four elements among 25 kinds of elements were K, S, Cl, and Cd, and K can be used as identity element of ETS during the sources apportionment of indoor particulate matter. The highest level of ion is SO42-.Secondly, the natural attenuation of PM released from cigarette burning was studied. Two cigarettes were burned in a cube charmer (0.8mx0.8mx0.8 m). The concentration of PM in the experimental chamber was monitored online during the whole course of the experiment using the Sequential Mobility Particle Size analyzer (SPMS). The particle size distribution by number concentration was mainly from 100 to 800nm, and the peak diameter was about 290nm. The concentration of PM released from cigarette burning significantly reduced with the increasing of environmental relative humidity (RH), but there was no significantly effect on the size distribution when the ambient humidity increased. PM released from cigarette burning would naturally decay because of the coagulation effect or the wall effect. The decay rate of small-size particles was faster than the large-size particles, and RH significantly affected the attenuation of small-size particle.Finally, using a self-designed electrostatic precipitator, the purification of PM released from cigarette burning was studied. The influence of three factors (applied voltage of the precipitator, environmental relative humidity, and the burning rate of cigarette) on particle removal efficiency was investigated respectively. The experimental result indicated that:PM released from cigarette burning could be effectively removed by electrostatic precipitators, and the optimum particle size range for PM removal is 0.4-2.1 μm. The purification efficiency was enhanced with the increasing the applied voltage. Considering the energy efficiency ratio (EER) 20kV was proposed as the optimal applied voltage. Increasing environmental RH was benefitted for improving the purification efficiency of large-size particles (d>2um), while there was no significant influence on small-size particles. There was different purification efficiency of PM because the particle size distribution was changed under different burning rate of cigarette.