南通市重污染过程PM_(2.5)中OC/EC浓度水平及污染特征分析

采用EC/OC在线分析仪连续监测数据,结合空气自动监测站监测的PM_(2.5)浓度数据和气象参数,对南通市几次重污染过程进行了分析。结果表明,OC/EC浓度随PM_(2.5)浓度变化趋势基本一致,重污染过程中明显升高,是导致南通市重污染天气的重要元素之一。重污染过程中存在明显的二次有机碳污染,且重污染程度越高,二次有机污染越严重。单次重污染过程OC/EC来源基本相同,仅凭OC/EC的比值判断污染物来源是不充分的。污染过程中TC(OC+EC)的上升幅度较PM_(2.5)中其他组分低,污染后其下降幅度也相对较低。

Concentrations and Pollution Characteristics of Organic Carbon and Elemental Carbon in PM2.5 during the Heavy Air Pollution Episodes in Nantong

In this paper, EC/OC online analyzer was used for continuous data monitoring and several heavy air pollution episodes were studied on the basis of the PM2.5concentrations and meteorological data monitored by the automatic air quality monitoring stations. The results showed that OC/EC concentrations significantly increased during the heavy air pollution episodes, indicating a similar change trend withPM2.5concentrations, which was one of the important elements leading to heavy air pollution. Secondary organic carbon pollution obviously existed during the heavy air pollution episodes. The heavier the air pollution was, the worse the secondary organic pollution was. The emission source of OC and EC was basically the same in each pollution event. The ratio of OC to EC could not be used as the only index for determination of the pollutant emission source. The increasing range of TC(OC+EC) was less than those of other components in PM2.5 and its decreasing range was also comparatively less.