基于长光程DOAS 技术的航道区域船舶空气污染物排放监测研究

利用长程差分光学吸收光谱技术对黄浦江下游典型航道区域船舶排放的空气污染物进行高时间分辨率监测。 研究表明 SO2 浓度受船舶尾气烟羽影响显著, 浓度瞬时可增高 2～4 倍不等, 峰值超过 10×10?9 (体积混合比); 而由于 来源情况更为复杂, NO2 浓度的变化较为平缓, 且由于受到周围机动车排放影响, 日变化呈现出明显的双峰特征。受 船流量影响, SO2 浓度在日间相对较高。人为活动影响分析表明, NO2 浓度在春节假期相较于前后时段下降 30%以上, 而在新冠疫情重大突发公共卫生事件一级响应启动后下降达 50%。值得注意的是, 由于船舶活动规律的差异性, SO2 浓度的假期效应以及对疫情响应措施的反应并不明显, 但 SO2 浓度的典型排放高值呈现逐年下降的趋势。

Monitoring of Ship Emission in Shipping Channel Area Based on Long-Path DOAS Technique

Utilizing long-path differential optical absorption spectroscopy technique, air pollutants from ship emission in typical shipping channel area of the downstream of Huangpu River were measured with high temporal resolution. It is found that SO2 concentration can increase by 2 to 4 times instantaneously and reach more than10×10^-9 due to the significant impacts of ship plume. However, since its emission sources are more complicated,the variation of NO2 concentration is relatively gentle, and under the influence of vehicle emission nearby, the diurnal variation of NO2 concentrations shows obvious bimodal characteristic. Affected by ship flow, SO2 concentration is relatively high in daytime. The analysis of the impact of human activities demonstrats that the NO2 concentration dropped by more than 30% during the Spring Festival holidays compared with that before and after, and even decreased to 50% after the first-level response to major public health emergencies of COVID-19. It is worth noting that the response of SO2 concentration to the control measures of COVID-19 and holiday effect is not so obvious as that of NO2 due to the differences of ship activity. However, the typical high emission value of SO2 concentration has shown a downward trend year by year.