Seasonal and diurnal variations of volatile organic compounds (VOCs) in the atmosphere of Hong Kong
Seasonal and diurnal variations of volatile organic compounds (VOCs) in the atmosphere of Hong Kong
复制标题
DOI：
10.1016/j.scitotenv.2003.10.004
复制
发表时间：
2004-04-25
影响因子：
9.8
通讯作者：
Tsai, W
中科院分区：
文献类型：
--
作者：
Ho, KE;Lee, SC;Tsai, W
于2000年11月至2001年2月和2001年6月至8月期间，在香港三个地点(理大校园、观塘和鹤咀)采集了空气中挥发性有机化合物的样本。此外，我们亦取得香港海底隧道内挥发性有机化合物的浓度，以确定挥发性有机化合物的车辆来源。甲苯是香港检测到的最丰富的VOC。在靠近一条主干道的PU站，大多数VOCs的浓度在夏季高于冬季。然而，在本底位置，除四氯乙烯外，所有VOCs的浓度冬季均高于夏季。区域物理扩散/输送和混合深度可能是冬季高温地区VOC浓度较高的原因。冬季PU和KT的BTEX(苯：甲苯：乙苯：二甲苯)分别为(1.9：10.1：1.0：1.8)和(1.9：10.4：1.0：1.5)，夏季分别为(0.9：8.3：1.0：2.2)和(0.8：29.6：1.0：1.8)。在这项研究中，用二甲苯/乙苯(X/E)比值来评估气团的相对年龄。香港大气中挥发性有机化合物的浓度主要受车辆直接排放、燃料蒸发、光化学反应和少量工业排放的影响。隧道内苯系物比例为2：10.4：1：3.2。冬季PU和KT的苯系物比率与隧道中的相似(二甲苯除外)。隧道内的X/E比高于环境空气中的X/E。这表明隧道中新释放的二甲苯的衰减速度与大气中的OH-氧化的速率不同。冬季PU和KT具有良好的BTEX相关性(r>；0.8)(**P
Ambient VOCs samples were collected at three locations (PolyU campus (PU), Kwun Tong (KT), Hok Tsui (HT)) in Hong Kong during the periods of November 2000-February 2001 and June 2001-August 2001. Also the concentrations of VOCs in Cross Harbor tunnel in Hong Kong were obtained in order to determine the vehicular sources of VOCs. Toluene was the most abundant VOC detected in Hong Kong. At the PU station, which is close to a main road, the concentrations of most VOCs were higher in summer than in winter. However, at the background location HT, the concentrations of all VOCs except tetrachloroethene were higher in winter than in summer. Regional physical dispersion/transportation and mixing depth may be the reasons for higher VOC concentrations in winter at HT. The BTEX (benzene:toluene:ethylbenzene:xylene) ratios of PU and KT during winter period were (1.9:10.1:1.0:1.8) and (1.9:10.4:1.0:1.5), and (0.9:8.3:1.0:2.2) and (0.8:29.6:1.0:1.8) for summer season, respectively. The xylene/ethylbenzene (X/E) ratio was used to assess the relative age of the air parcels in this study. The concentrations of VOCs in the atmosphere in Hong Kong were mainly affected by direct emissions from vehicles, evaporation of fuels, photochemical reactions and few industrial emissions. The BTEX ratio in the tunnel was 2:10.4:1:3.2. The BTEX ratios at PU and KT during the winter period were similar to that in tunnel (except for xylenes). The X/E ratio in the tunnel was higher than that in the ambient air. This indicated that the freshly emitted xylenes in the tunnel decayed at different rates from OH-oxidation in the atmosphere. Good BTEX correlations (r> 0.8) were found at PU and KT in winter (**P