Journal of Environmental Sciences, Год журнала: 2023, Номер 138, С. 684 - 696
Опубликована: Май 4, 2023
Язык: Английский
Journal of Hazardous Materials, Год журнала: 2022, Номер 430, С. 128406 - 128406
Опубликована: Фев. 2, 2022
Язык: Английский
Процитировано
54
Gondwana Research, Год журнала: 2021, Номер 93, С. 243 - 251
Опубликована: Фев. 10, 2021
Язык: Английский
Процитировано
47
The Science of The Total Environment, Год журнала: 2022, Номер 841, С. 156740 - 156740
Опубликована: Июнь 16, 2022
Язык: Английский
Процитировано
32
The Science of The Total Environment, Год журнала: 2021, Номер 818, С. 151700 - 151700
Опубликована: Ноя. 16, 2021
Язык: Английский
Процитировано
41
The Science of The Total Environment, Год журнала: 2021, Номер 810, С. 151187 - 151187
Опубликована: Окт. 29, 2021
We investigated speciation and levels of organosulfates, organosulfonates as well carboxylic acids in aerosol samples collected during summer (2014) winter (2014/15) Xi'an, Northwest China, to improve understanding composition sources organic aerosols this region heavily affected by air pollution. Organosulfates are formed from reactive gas-phase compounds acidic sulfate aerosols, contributing secondary SOA. The show a large diversity organosulfur species line with other regions reflecting the high complexity SOA precursors. In samples, organosulfates isoprene prevalent due transport masses southern isoprene-emitting mountain forests. During winter, local or areas north city low population density very temperatures. estimated (768 ± 346 ng m-3) (938 374 more similar than expected given carbon indicating formation processes. observed an organosulfonate molecular weight 214 (C6H14O6S) at (254 232 but much lower concentrations (12 13 summer. High were mainly pH below about 2.5. Concentrations oxidation monoterpenes (5.2 2.7 m-3 summer). Phthalic acid was 90 29 correlated highly carbon, chloride potassium, common origin, most likely burning biomass plastic-containing waste. Further research is needed elucidate organosulfonates, impact on properties affecting e.g. health effects.
Язык: Английский
Процитировано
35
Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(15), С. 10139 - 10153
Опубликована: Авг. 9, 2022
Abstract. Secondary organic aerosol (SOA) plays an important role in particulate air pollution, but its formation mechanism is still not fully understood. The chemical composition of non-refractory matter with a diameter ≤2.5 µm (NR-PM2.5), OA sources, and SOA mechanisms were investigated urban Xi'an during winter 2018. fractional contribution to total mass (58 %) was larger than primary (POA, 42 %). Biomass-burning-influenced oxygenated (OOA-BB) resolved formed from the photochemical oxidation aging biomass burning (BBOA). OOA-BB more favorable on days fraction higher BBOA concentration. In comparison, aqueous-phase processed (aq-OOA) dependent secondary inorganic (SIA) content liquid water (ALWC), it showed large increase (to 50 % OA) SIA-enhanced periods. Further van Krevelen (VK) diagram analysis suggests that addition carboxylic acid groups fragmentation dominated reference days, while increased aq-OOA contributions periods likely reflect evolution due alcohol or peroxide groups.
Язык: Английский
Процитировано
27
Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(2), С. 1147 - 1167
Опубликована: Янв. 23, 2023
Abstract. Haze pollution is a severe environmental problem, caused by elevation of fine particles (aerodynamic diameter <2.5 µm, PM2.5), which related to secondary aerosol formation, unfavourable synoptic conditions and regional transport, etc. The haze formation in basin areas, along with intensive emission precursors, high relative humidity poor dispersion conditions, still limitedly understood. In this study, field campaign was conducted investigate the factors resulting Sichuan Basin (SCB) during winter 2021. chemical composition characterised using time-of-flight speciation monitor (ToF-ACSM), also provided detailed information on sources for organic aerosols (OAs). average concentration non-refractory (NR-PM2.5) 98.5±38.7 µg m−3, organics aerosols, nitrate, sulfate, ammonium chloride took up 40.3 %, 28.8 10.6 15.3 % 5.1 PM2.5. Three factors, including hydrocarbon-like OA (HOA), biomass burning (BBOA) an oxygenated (OOA), were identified applying positive matrix factorisation (PMF) analysis, they constituted 24.2 51.6 average, respectively. Nitrate promoted gas-phase aqueous-phase oxidation, while sulfate mainly formed through process. OOA showed strong dependence Ox, demonstrating contribution photooxidation formation. increased as liquid water content (ALWC) within 200 m−3 kept relatively constant when ALWC >200 suggesting insignificant effect reactions Among three episodes whole campaign, driving different: first episode (H1) driven nitrate photochemical reactions, second (H2) intense primary from vehicle exhaust, third (H3) involving emission. HOA BBOA scavenged, OOA, enhanced fog periods, resulted increase O:C pre-fog post-fog periods. This study revealed SCB implied benefit controlling well exhaust mitigation heavy region.
Язык: Английский
Процитировано
14
Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(9), С. 5419 - 5433
Опубликована: Май 16, 2023
Abstract. Secondary organic aerosol (SOA) has been identified as a major contributor to fine particulate matter (PM2.5) in the North China Plain (NCP). However, chemical mechanisms involved are still unclear due incomplete understanding of its multiple formation processes. Here we report field observations summer Handan NCP, based on high-resolution online measurements. Our results reveal SOA via photochemistry and two types aqueous-phase chemistry, latter which include nocturnal daytime processing. The photochemical pathway is most important under high-Ox (i.e., O3 + NO2) conditions (65.1 ± 20.4 ppb). efficient from (Ox-initiated SOA) dominated (65 % OA), with an average growth rate 0.8 µgm-3h-1. During high-relative-humidity (RH; 83.7 12.5 %) period, strong (aqSOA) played significant role production (45 nighttime 0.6 Meanwhile, equally fast µgm-3h-1 Ox-initiated was also observed, contributed 39 OA, showing that aqueous phase non-negligible summer. primary-related (SOA attributed primary organics) aqSOA related residential coal combustion activities, supported by distinct fragments polycyclic aromatic hydrocarbons (PAHs). Moreover, conversion rapid oxidation were possible high-RH conditions. This work sheds light pathways ambient air complex pollution improves our aging high capacity.
Язык: Английский
Процитировано
11
Environmental Science & Technology Letters, Год журнала: 2023, Номер 10(7), С. 573 - 581
Опубликована: Июнь 13, 2023
Secondary organic aerosols (SOAs) account for a large fraction of atmospheric fine particles, but the mechanisms their formation and evolution processes remain unclear. In this study, ground-based counterflow virtual impactor was used in combination with an online time-of-flight aerosol chemical speciation monitor to investigate multiphase (gaseous aqueous) oxidation SOA influencing factors during cloud events at mountain site southern China. Our results showed that clouds promoted low-oxidized oxygenated (LO-OOA) more-oxidized (MO-OOA). At night, ozone (O3) nitrate radicals (NO3•) oxidized volatile compounds (VOCs, mostly biogenic VOCs) precursors LO-OOA were absorbed droplets form LO-OOA, while hydroxyl radical (•OH) main oxidant daytime. droplets, further by •OH MO-OOA. We propose isoprene can be products gas phase then acidic 2-methylglyceric acid (2-MG), 2-MG-organosulfate, 2-MG-organonitrate. This study improves our understanding formation, driven events.
Язык: Английский
Процитировано
11
Environmental Research, Год журнала: 2024, Номер 252, С. 119009 - 119009
Опубликована: Апрель 26, 2024
Язык: Английский
Процитировано
4