西宁远郊区春末夏初PM_(2.5)污染特征及其影响因素分析

Analysis of Pollution Characteristics and Effect Factors of PM_(2.5) in Late Spring and Early Summer in Exurbia of Xining

于2012年5-6月对西宁市远郊区环境空气中PM2.5的质量浓度进行实时监测,研究其主要分布特征及其影响因素。研究结果表明：西宁市郊区可吸入颗粒物污染相当严重,PM2.5日平均质量浓度为（122.8±44.67）μg·m-3,日均值的频数分布显示大量的值位于75~175μg·m-3之间,周末明显比工作日高,PM2.5小时均值浓度日变化呈双峰分布,峰值分别出现于9：00与19：00左右,与早晚交通高峰期吻合,第一峰值出现在白天。PM2.5质量浓度在工作日与周末存在明显差异;利用XRD分析PM2.5以及表面土壤的矿物相,发现二者矿物相相似;在5-6月份PM2.5质量浓度与常规气象因素之间没有显著的相关性。

The mass concentration of PM2.5 was continuously measured during the period from May to June in 2012 in the exurbia of Xining, capital of west China＇ s Qinghai province. The distribution features of PM2.5 mass concentration and its influence factors were analyzed. It was found that the particulate air pol- lution in Xining is very serious, and the 24 h average of PM2.5 mass concentration was （122.8 ＋44.67） -3 μg m^-3 , with the frequency the range from 75 to 175 μg m^-3 distributions of PM2.5 concentrations showing that most of the values were in . The concentration in weekends was higher than that of weekdays, the diurnal variations of PM2.5 mass concentration consist of two peak values, one was at 9：00 and the other was at 19：00, which were mainly attributed to the heavy traffic in rush hours. The first peak value of the PMz 5 mass concentration came in the day. The concentration of PM2.5 in weekends was higher than that of weekdays. Analyzed by X - ray diffraction （XRD）, the mineral phases of PM2.5 and superficial soil of Xining were similar. The relationship between the PM2.5 mass concentration and the general meteorological factors was not that significant.