Zhou Jing-Qing, Yu Lei, Chen Shu-Xin, Lu Jia-Feng, Xu Ya-Lu, Ji Hai-Bing, Zhang Liu-Fang, Liu Jin-Song, Wang Jing
Zhejiang Key Laboratory of Ecological and Environmental Monitoring, Forewarning and Quality Control, Zhejiang Ecological and Environmental Monitoring Center, Hangzhou 310012, China.
Huan Jing Ke Xue. 2023 Mar 8;44(3):1297-1309. doi: 10.13227/j.hjkx.202203118.
To investigate the seasonal and regional pollution characteristics of PM chemical composition in Zhejiang province, this study was based on manual sampling monitoring data from 11 sampling sites of four regions in Zhejiang province from October 1, 2019 to September 30, 2020. The results showed that during the observation period, the average (PM) of the four regions ranged from 34.3 μg·m to 46.4 μg·m. The PM mass concentrations in the hinterland areas of western Zhejiang and northern Zhejiang were relatively high, 15.1% and 13.2% higher than the mean value, respectively. The PM mass concentrations in the coastal areas of eastern Zhejiang and southern Zhejiang were relatively low, 8.4% and 14.9% lower than the average, respectively. The seasonal characteristics showed a higher concentration in autumn and winter and lowest concentration in summer. The seasonal variation in PM mass concentration from autumn to spring was not obvious in southern Zhejiang, whereas in western Zhejiang, the PM mass concentration followed a descending sequence of autumn>winter>spring>summer. In northern Zhejiang and eastern Zhejiang, the trend was winter>autumn>spring>summer. During the observation period in the inland area, the (PM) of the scenic area, administrative area, residential area, and mixed area of commercial traffic and residents were (40.2±10.2), (46.3±9.6), (50.1±10.6), and (46.7±10.2) μg·m, respectively. The highest value of (PM) was in the residential area. During the sampling period in coastal areas, the (PM) of the cultural and entertainment area and mixed area of commercial traffic and residents were (27.4±5.8) μg·mand (37.2±5.6) μg·m, respectively. The contribution rates of organic matter (OM), NO, SO, NH, trace elements, and crustal matter in PMwere 26.4%, 15.4%, 12.4%, 9.0%, 7.1%, and 5.7%, respectively. The SNA, including SO, NO, and NH, contributed 36.8% in PM. In terms of seasons, the contribution of OM to PM in autumn, spring, and summer was higher than that of other compositions, which accounted for 28.3%, 27.7%, and 26.3%, respectively. The contribution rate of NO in PM was the largest in winter, reaching 24.3%. In terms of spatial distribution, SNA contributed the most to PM in all regions, ranging from 32.8% to 39.7%, with the highest in northern Zhejiang and the lowest in southern Zhejiang. The SNA of all regions presented NO>SO>NH. Based on the backward trajectory clustering analysis, the main air sources of northern Zhejiang were the Yellow Sea-southern Jiangsu (autumn), northern Anhui (winter), East China Sea (spring), and western Jiangsu (summer) areas, with contribution rates of 38.11%, 35.28%, 37.46%, and 27.87%, respectively. The main air sources of western Zhejiang were the Yellow Sea-southern Jiangsu (autumn), southern Anhui (winter), eastern Zhejiang (spring), and northern Zhejiang (summer), with contribution rates of 38.11%, 37.50%, 46.55%, and 32.58%, respectively. The air of autumn, winter, spring, and summer in eastern Zhejiang were influenced by air masses from northern Hebei (36.07%), eastern Shandong (38.06%), East China Sea (30.17%), and southern Guangdong (34.43%), respectively. In autumn, winter, spring, and summer, southern Zhejiang was affected by air masses from the Yellow Sea (35.66%), northeast Anhui (34.44%), East China Sea (26.72%), and southern Fujian coast (35.00%), respectively. The regions in Zhejiang province showed large seasonal differences. The difference value between the maximum value of (PM) in the northwest and the lowest value in the southeast was 21.0 μg·m and 20.5 μg·m in autumn and winter, respectively; the difference values in spring and summer were 10.4 μg·m and 6.1 μg·m. Thus, the northern air mass had a certain exogenous contribution to PM in autumn and winter in Zhejiang province. However, with the weakening of the northern air mass trajectory in spring and summer and the increasing contribution of the southern and east China Sea air mass to the air flow in Zhejiang province, PM pollution showed a trend of improvement.
为研究浙江省细颗粒物（PM）化学成分的季节和区域污染特征，本研究基于2019年10月1日至2020年9月30日浙江省四个地区11个采样点的手工采样监测数据。结果表明，观测期内，四个地区的PM平均值在34.3μg·m至46.4μg·m之间。浙西和浙北内陆地区的PM质量浓度相对较高，分别比平均值高15.1%和13.2%。浙东和浙南沿海地区的PM质量浓度相对较低，分别比平均值低8.4%和14.9%。季节特征表现为秋冬浓度较高，夏季浓度最低。浙南地区秋冬至春季PM质量浓度的季节变化不明显，而浙西地区PM质量浓度呈秋季>冬季>春季>夏季的递减顺序。浙北和浙东地区的趋势是冬季>秋季>春季>夏季。在内陆地区观测期内，风景区、行政区、居民区以及商业交通与居民混合区的PM分别为（40.2±10.2）、（46.3±9.6）、（50.1±10.6）和（46.7±10.2）μg·m，其中居民区的PM最高。在沿海地区采样期内，文化娱乐区以及商业交通与居民混合区的PM分别为（27.4±5.8）μg·m和（37.2±5.6）μg·m。PM中有机物（OM）、NO、SO、NH、微量元素和地壳物质的贡献率分别为26.4%、15.4%、12.4%、9.0%、7.1%和5.7%。包括SO、NO和NH在内的硫氮化合物（SNA）在PM中的贡献率为36.8%。在季节方面，OM在秋季、春季和夏季对PM的贡献率高于其他成分，分别占28.3%、27.7%和26.3%。NO在PM中的贡献率在冬季最大，达到24.3%。在空间分布方面，SNA在所有地区对PM的贡献最大，范围为32.8%至39.7%，浙北最高，浙南最低。所有地区的SNA均呈现NO>SO >NH。基于后向轨迹聚类分析，浙北的主要空气来源是黄海 - 苏南（秋季）、皖北（冬季）、东海（春季）和苏北（夏季）地区，贡献率分别为38.11%、35.28%、37.46%和27.87%。浙西的主要空气来源是黄海 - 苏南（秋季）、皖南（冬季）、浙东（春季）和浙北（夏季），贡献率分别为38.11%、37.50% 、 46.55%和32.58% 。浙东秋冬春夏季的空气分别受来自冀北（36.07%）、鲁东（38.06%）、东海（（30.17%）和粤南（34.43%）气团的影响。浙南秋冬春夏季分别受来自黄海（35.66%）、皖东北（34.44%）、东海（26.72%）和闽南沿海（35.00%）气团的影响。浙江省各区域呈现出较大的季节差异。西北（PM）最大值与东南最小值在秋季和冬季的差值分别为21.0μg·m和20.5μg·m；春季和夏季的差值分别为10.4μg·m和6.1μg·m。因此，北方气团对浙江省秋冬季节的PM有一定的外源贡献。然而，随着春夏季节北方气团轨迹的减弱以及南方和东海气团对浙江气流贡献的增加，PM污染呈现改善趋势。
