Study On Emission Of VOCs From Diffierent Kinds Of Furniture Plates

In this paper, the release of VOCs from 6 kinds of furniture plate (24 pieces of board) purchased directly from the furniture plate market were studied in a static chamber with 500L volume. Three different experiments were completed in this paper. (1)A class of long-term experiments about 12-15 days was carried out to study the kinds and concentrations of VOCs released from the six kinds of furniture plate under normal indoor conditions. In these experiments, the release of VOCs in the experiment chamber had reached equilibrium and the concentrations of VOCs were not changed after the release of 12-15 days. (2) A class of short-term experiments about 8 hours was carried out to study the release rates of 15 kinds of specific VOCs released from 24 pieces of board under normal indoor conditions. In these experiments, the release of VOCs in the experiment chamber had not reached equilibrium and the average release rates of VOCs were calculated by the concentrations of VOCs after the release of 8 hours. (3) A class of photo oxidation experiments was carried out to study the decrease of gas pollutions, such as NO2, NO, and O3, and the increase of particulate matter when kinds of VOCs existed in the reaction system. The aim of this experiment was to find the conversion rules from VOCs to secondary organic aerosol (SOA). VOCs were monitored by the proton transfer reaction time of flight mass spectrometer and portable gas chromatography with photo ionization detector (GC-PID). UV lamps with the dominant wavelength of 254 nm were used as light source in photo oxidation experiments. All conclusions were as follows:The major target VOCs released from furniture plates were alkanes, alkenes, aromatic hydrocarbons, aldehydes and ketones, ethyl acetate, and methyl acetate and so on. The concentrations and the kinds of VOCs released from four kinds of furniture plates were not same. The total concentration of VOCs released from glulam was 11.45 mg/m3, which was the highest among the concentrations of VOCs released from four plates. The top ten VOCs according to the equilibrium concentration were pentane> butane> propane> methyl bromide> isoprene> formaldehyde> acetonitrile> cyclohexane> acetaldehyde> methanol; the equilibrium concentration of VOCs released from plywood was 3.75 mg/m3, the top ten VOCs according to the equilibrium concentration were propane> pentane> formaldehyde> butane> methanol> N-nonane> ethane> methyl cyclohexane> isoprene> acetonitrile; the equilibrium concentration of VOCs released from Shaving board was 1.85mg/m3, the top ten VOCs based on equilibrium concentration were pentane> butane> propane> Methyl bromide> isoprene> formaldehyde> acetonitrile> cyclohexane> acetaldehyde> methanol; the equilibrium concentration of VOCs released from density board was 0.5 mg/m3,which was the lowest among the concentrations of VOCs released from four plates. The top ten VOCs depended on the equilibrium concentration were ethane> formaldehyde> eleven alkyl> n-Nonane> toluene> isoprene> acetaldehyde> cyclohexane> acetonitrile> methyl chloride.Using the SPSS hierarchical clustering on the release rates of 24 plates, it divided 24 plates into 5 categories. The furniture plates in the first layer mainly released the pollutant was three methyl bromide, the average rate emission of three methyl bromide was 324.51ug/m-3h-1; the emission characteristics of the second layer had two target pollutants which were isoprene and toluene, the max rates of emission of them respectively were 718.97 ug/m-3h-1 and 345.19ug/m-3h-1; the third layer released VOCs which had complex kinds and the concentrations were lower (all concentrations of the pollutants released from the third layer were less than 50 ug/m-3h-1), this layer has no characteristic VOCs. The forth layer mainly released formaldehyde, methanol, methacrolein and methyl vinyl formaldehyde, the average emission rates of them were 15.12 ug/m-3h-1,20.63 ug/m-3h-1 and 12.39ug/m-3h-1; The fifth layer mainly released styrene and methyl cyclohexane, the max rates of emission of them were 258.39ug/m-3h-1 and 572.71ug/m-3h-1.In photo-oxidation experiments, the final change trends of NOx and NO2 all were rising, while the concentration of NO in the end stage of the experiment basically were exhausted or near to the background concentration. The PM was increasingly generated when NO was exhausted. The number concentrations of PM were changing hundreds of times. The concentration of PM had positive correlation with the feature of target pollutants which were furniture plates released, the concentration of TVOC, and the changes of concentration of NOx and O3.