Feature analysis on air quality in the main urban area of Nanchong City in 2015–2018

Abstract

This study evaluates the air quality in Nanchong City in 2015–2018 based on automatic monitoring data and meteorological data in the main urban area. Results show that overall air quality in the main urban area of Nanchong was standard and improved from 2015 to 2018. SO2, NO2, and CO had slight influences on air quality in the study area, whereas excessive annual average PM2.5 and increasing O3 concentration challenged the air quality. The monthly average mass concentrations of particulate matters (PM2.5 and PM10), NO2, and CO generally presented a “U-shaped” distribution pattern while O3 showed the opposite. The diurnal variation of PM, NO2, and CO has two peaks related to the morning and evening rush hours. Vehicle exhaust is the main source of local pollution. Over-standard PM2.5 can significantly inhibit O3 production while O3 can easily promote the secondary generation of PM2.5 due to its strong oxidization. PM2.5 emission should be controlled strictly in winter, while in summer, the sources of O3 should be controlled vigorously. Air pollution is comprehensive and complicated and is influenced by various factors, mainly meteorological and human factors. Measures such as artificial rainfall should be included at the appropriate time to cope with adverse meteorological conditions when heavy pollution occurs in winter.

Characteristics and Sources Analysis of Carbonaceous Aerosols in Urban and Rural Areas of Nanchong City

“…Basin and affected the PM concentration of Nanchong at times [33]. Because dust particles are mainly composed of larger particles, the concentrations of PM 10 and PM 2.5 in the air rise simultaneously in dusty weather, but the increase in the range of PM 10 is much higher than that of PM 2.5 , resulting in a significant decline in the PM 2.5 /PM 10 ratio.…”

“…It can be concluded that PM 2.5 pollution in Nanchong was relatively severe during the study period. Lei et al [33] found that PM 2.5 was the main non-attainment pollutant in the urban areas of Nanchong City from 2015 to 2018, and the annual average concentrations of PM 2.5 exceeded 35 μg /m 3 for four consecutive years. Similarly, the other cities in the Sichuan Basin also showed severe PM 2.5 pollution between 2009 and 2016 [14,[34][35].…”

“…However, unlike in northern cities in China, there was no extensive coal combustion or wood burning in winter because of the warm temperatures (approximately 10ºC on average) in the Sichuan Basin [45][46]. Therefore, the PM concentrations of the cities in the Sichuan Basin during winter were more affected by atmospheric processes and meteorological conditions [33,40,47].…”

The Aerosol Optical Characteristics in Different Dust Events Based on a 532 nm and 355 nm Polarization Lidar in Beijing

“…In addition to cyclones or anticyclones, the transit of a cold front indirectly contributed to the increase in the particulate matter (PM) concentration in Shijiazhuang via the long-transported upper airflow [23]. Furthermore, the relationship between PM concentrations and wind speed in dust pollution was also investigated [24].…”

Influences of magnetic field on the removal of submicron particles in electrostatic cyclone at different temperatures

“…In recent years, with the continuous occurrence of haze in major cities in China [1][2], air quality has become increasingly worse. More and more attention has been paid to the harm caused by fine particles, with the emission of vehicle exhaust being of the main sources of pollution [3][4][5].…”