Development of less-polluting incense:Correlation between the main ingredients and emission characteristics of burning incense

• Main Authors: Chi-Ru Yang, 楊奇儒
• Other Authors: Ta-Chang Lin
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/47520472022876039615

博士 === 國立成功大學 === 環境工程學系碩博士班 === 94 === A combustion chamber study was conducted for nine types of incenses. They were separately burned in the chamber continuously supplied with clean and filtered air. Solid and gas phase pollutants from each burned incense were quantitatively collected with a micro-orifice uniform deposited impactor (MOUDI) and an XAD-2 cartridge, respectively. The main metallic contents in raw material incense were analyzed by inductively coupled plasma atomic emission spectrometry; influence of the main metallic contents upon the characteristics of combustion was evaluated. The metals content in different types incense were obviously different. However, the order of quantities of metal elements was similar in all incenses. The contents of Ca and K were the highest among all metallic elements in the raw materials of the incense. Under the same burning conditions, the combustion duration, burning rate, ash emission factor, and particulate emission factor and ash generation rate varied among different types of incense. The particulate generation rates are however quite similar among all incense — the shorter the combustion duration of a stick, the lower the total suspended particulate emission. Additionally, with the same incense weight burned, the greater the emission of ash, the lower the emission of suspended particulate. Consumers can select healthy incense based on these results. The average mass median aerodynamic diameter (MMAD) of the smoke aerosol was 262 ± 49 nm. Coagulation was a major mechanism that dictates the MMAD of the smoke. For each type of incense investigated in this study, the Total-BaPeq of the P-PAHs was found to be consistently more than fifty times higher than that of the corresponding G-PAHs. No specific pattern in particle size distribution was found for P-PAHs. Appropriate amount of metals addedwould reduce the level of suspended particulates in incense burning. Ca was inorganic salt, CaCO3 which is added during production due to its low cost. More importantly, increasing the calcium content from 0.5 to 5.0% by adding CaCO3 reduced the particulate emission from incense by approximately 50%. Changing the calcium content from 0.5 to 2.0% would decrease 15-30% of the emission of P-PAHs. Therefore, addition of CaCO3 to the raw material incense will efficiently decrease genotoxic P-PAHs, hence reduce the damage to the human respiration system.