The characteristics of acidic aerosol in the battery room

• Main Authors: Kuo, Yi-Ming, 郭益銘
• Other Authors: Lee Wen-Jhy, Tsai Perng-Jy
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/06793591227969414192

碩士 === 國立成功大學 === 環境工程學系 === 86 === The purposes of this study are to investigate the concentration and characteristics of acidic aerosol in the communication battery rooms and battery-manufacturing factories by using several kinds of samplers, including denuder, silica- gel tube, IOM and 37mm cassette sampler. The study shows that the mean concentration of SO4-2 and H+ in the indoor air of communication battery rooms are 13.1 ug/m3 and 244 ng/m3 respectively , which are obviously elevated and affected by the batteries and are limited in the same floor with the communication battery rooms. It is also concluded that the communication batteries will not emit nitrate- or chloride- containing acidic aerosols. The highest mean concentration of SO4-2 and H+ in the battery-manufacturing factories were all in chemical engineering areas, while that of charging areas was the next. They were 207 ug/m3 of SO4-2 and 2840 ng/m3 of H+ in chemical engineering areas and 129 ug/m3 of SO4-2 and 1460 ng/m3 of H+ in the charging areas. The mean concentration of both nitrate and chloride in the chemical engineering areas are also higher than that of urban areas. This is due to nitrate and chloride are added to the electrolyte solution of chemical and charging engineering areas and evaporated into the air. In the indoor air of communication battery rooms, the particle size of SO4-2 were unimodal distribution and the peak is located between 0.52~1.8 um. However, in the indoor air of battery-manufacturing factories the particle size of SO4-2 was bimodal distribution and the peaks are located between 0.52~1.8 um and 5.6~10 um , respectively. There are two reason for the formation of the mode between 5.6~10 um. First, the sulfuric acid diffused into the air with the hydrogen generated during the process of electrolyzing . Second, The labors resuspended the sulfate deposited on the ground into the air. The particle size distributions of nitrate and chloride are both unimodal distribution. The particles in the battery-manufacturing factories have the tendency to grow as compared with that in the communication battery rooms due to its higher relative humidities. The relative measured value determined by all samplers are silica-gel > IOM > denuder > 37mm. Aspiration efficiency can be affected by the flow distortion ,which will lead to the difference of measured value between samplers. Silica-gel tube and IOM samplers have better aspiratin efficiency, so the measured valuedetermined by these two samplers are with more precision. However, the 37mm cassette has worse aspiration efficiency and its aspiration efficiency is easily affected by wind speed, so the measured value of acidic aerosol is usually under-estimated by the 37mm cassette.