摘要:
对广州市珠江隧道中气相和颗粒态样品,以及隧道附近大气样品中的二噁英类化合物(PCDD/Fs)进行了检测.结果表明,珠江隧道中17种2,3,7,8-氯取代二苯对二噁英和二苯并呋喃(包括气相和颗粒态)的浓度范围夏季(7月)为3830.9 fg·m-3—4690.2 fg·m-3,毒性当量为193.0 fg.I-TEQ·m-3—217.0fg.I-TEQ·m-3;冬季(12月)为18600.8 fg·m-3—20388.8 fg·m-3,毒性当量为1275.4fg.I-TEQ·m-3—1392.2 fg.I-TEQ·m-3;冬季浓度远远高于夏季,隧道内冬季浓度是夏季浓度的3—4倍.环境大气样品中PCDD/Fs浓度低于隧道.同时期样品中,隧道出口、隧道中间、隧道外以及沙面公园中PCDD/Fs的浓度呈递减趋势,并且在冬季这种趋势更加明显,冬季隧道内浓度是环境大气浓度的2倍(毒性当量为5倍).加权平均后PCDD/Fs的排放因子值为1994.6 pg·km-1·辆-1(104.8 pg I-TEQ).
Abstract:
The particulate and gaseous samples from Pearl river tunnel and its adjacent ambient air of Guangzhou were studied.The PCDD/Fs concentrations in tunnel in summer ranged from 3830.9 fg·m-3 to 4690.2 fg·m-3(193.0 fg·I-TEQ·m-3—217.0 fg·I-TEQ·m-3)while the concentrations in tunnel in winter were from 18600.8 fg·m-3 to 20388.8 fg·m-3(1275.4 fg·I-TEQ·m-3—1392.2 fg·I-TEQ·m-3).The concentrations in tunnel were higher than those in ambient;especially in winter,PCDD/Fs TEQ concentrations are about five times higher than those in ambient.The PCDD/Fs concentrations at sites from tunnel to its adjacent ambient air had a tendency of decline.The results indicate that the PCDD/Fs in the air of Guangzhou are at least partly emitted from the combustion processes of gasoline and diesel fueled cars.In term of data we measured,the emission factor(EF) and total emission amount per year was calculated.The EF of PCDD/Fs in Guangzhou was 1994.6 pg·km-1·vehicle-1(104.8 pg·I-TEQ).