Influence of Ambient Atmospheric Environments on the Mixing State and Source of Oxalate-Containing Particles at Coastal and Suburban Sites in North China

Photodegradation is a key process impacting the lifetime of oxalate in atmosphere, but few studies investigated this field due to complex mixing and sources oxalate. Oxalate-containing particles were measured via single-particle aerosol mass spectrometry at coastal suburban sites Qingdao, city North China summer 2016. The state influence different ambient conditions on source photodegradation investigated. Generally, 6.3% 12.3% total (by number) contained sites, respectively. Twelve major types oxalate-containing identified, they classified into three groups. Biomass burning (BB)-related oxalate–K oxalate–carbonaceous dominant groups, respectively, accounting for 68.9% 13.6% site 72.0% 16.8% site. Oxalate–Heavy metals (HM)-related represented 14.6% 9.3% which mainly from industrial emissions (Cu-rich, Fe-rich, Pb-rich), BB (Zn-rich), residual fuel oil combustion (V-rich). peak area decreased immediately after sunrise, while it increased during daytime However, Fe-rich both indicating that iron plays an important role degradation environments. decay rates (k) BB-Fe (−0.978 −0.859 h−1, respectively), greater than those (−0.512 −0.178 owing high-water content fewer precursors. estimated k values same order magnitude, can help establish or validate future atmospheric models.