Composition and source apportionment of saccharides in aerosol particles from an agro-industrial zone in the Indo-Gangetic Plain.

The characterization of saccharidic compounds in atmospheric aerosols is important in order to retrieve information about organic carbon sources and their transport pathways through the atmosphere. In this study, composition and sources of saccharides in PM10 were determined in a South Asian megacity (Faisalabad) during the year 2015 - 2016. PM10 sampled on quartz filters was analyzed by anion exchange chromatography for the selected saccharidic compounds. The average PM10 concentration was found to be 744 ± 392 µg m-3, exceeding the daily limits proposed by Pak-EPA (150 µg m-3), US-EPA (150 µg m-3), and WHO (50 µg m-3). The average total saccharidic concentration was found to be 2820 ± 2247 ng m-3. Among the different saccharidic categories, anhydrosugars were the most abundant in concentration followed by primary sugars and sugar alcohols. The correlation and principal component analysis indicated emissions from biomass combustion, soil suspensions from areas such as farmlands having high microorganism activity, and biogenic emissions such as airborne fungal spores and vegetation detritus as major sources of saccharides in the aerosol samples.

Chemical characterization of PM2.5 collected from a rural coastal island of the Bay of Bengal (Bhola, Bangladesh).

This work focuses on the chemical characterization of fine aerosol particles (PM2.5) collected from a rural remote island of the Bay of Bengal (Bhola, Bangladesh) from April to August, 2013. PM2.5 particle-loaded filters were analyzed for organic carbon (OC), elemental carbon (EC), water-soluble ions, and selected saccharides (levoglucosan, mannosan, galactosan, arabitol, and mannitol). The average PM2.5 mass was 15.0 ± 6.9 µg m-3. Organic carbon and elemental carbon comprised roughly half of the analyzed components. Organic carbon was the predominant contributor to total carbon (TC) and accounting for about 28% of PM2.5 mass. Secondary organic carbon (SOC) was inferred to be ~ 26% of OC. The sum of ions comprised ~ 27% of PM2.5 mass. The contribution of sea salt aerosol was smaller than expected for a sea-near site (17%), and very high chloride depletion was observed (78%). NssSO42- was a dominant ionic component with an average concentration of 2.0 µg m-3 followed by Na+, NH4+, and nssCa2+. The average concentration of arabitol and mannitol was 0.11 and 0.14 µg m-3, respectively, while levoglucosan and its stereoisomers (mannosan and galactosan) were bellow detection limit. NH4+/SO42- equivalent ratio was 0.30 ± 0.13 indicating that secondary inorganic aerosol is not the main source of SO42-. Enrichment factor (EF) analysis showed that SO42- and NO3- were enriched in atmospheric particles compared to sea aerosol and soil indicating their anthropogenic origin. Higher OC/EC ratio (3.70 ± 0.88) was a good indicator of the secondary organic compounds formation. Other ratios (OC/EC, K+/EC, nssSO42-/EC) and correlation analysis suggested mixed sources for carbonaceous components. Arabitol and mannitol both showed strong correlation with EC having R 2 value 0.89 and 0.95, respectively. Air mass trajectories analysis showed that concentrations of soil and anthropogenic species were lower for air masses originating from the sea (May-August) and were higher when air came from land (April).

Odor, gaseous and PM10 emissions from small scale combustion of wood types indigenous to Central Europe.

In this study, we investigated the emissions, including odor, from log wood stoves, burning wood types indigenous to mid-European countries such as Austria, Czech Republic, Hungary, Slovak Republic, Slovenia, Switzerland, as well as Baden-Württemberg and Bavaria (Germany) and South Tyrol (Italy). The investigations were performed with a modern, certified, 8 kW, manually fired log wood stove, and the results were compared to emissions from a modern 9 kW pellet stove. The examined wood types were deciduous species: black locust, black poplar, European hornbeam, European beech, pedunculate oak (also known as "common oak"), sessile oak, turkey oak and conifers: Austrian black pine, European larch, Norway spruce, Scots pine, silver fir, as well as hardwood briquettes. In addition, "garden biomass" such as pine cones, pine needles and dry leaves were burnt in the log wood stove. The pellet stove was fired with softwood pellets. The composite average emission rates for log wood and briquettes were 2030 mg MJ-1 for CO; 89 mg MJ-1 for NOx, 311 mg MJ-1 for CxHy, 67 mg MJ-1 for particulate matter PM10 and average odor concentration was at 2430 OU m-3. CO, CxHy and PM10 emissions from pellets combustion were lower by factors of 10, 13 and 3, while considering NOx - comparable to the log wood emissions. Odor from pellets combustion was not detectable. CxHy and PM10 emissions from garden biomass (needles and leaves) burning were 10 times higher than for log wood, while CO and NOx rise only slightly. Odor levels ranged from not detectable (pellets) to around 19,000 OU m-3 (dry leaves). The odor concentration correlated with CO, CxHy and PM10. For log wood combustion average odor ranged from 536 OU m-3 for hornbeam to 5217 OU m-3 for fir, indicating a considerable influence of the wood type on odor concentration.