13C- and 14C-based study of sources and atmospheric processing of water-soluble organic carbon (WSOC) in South Asian aerosols

Kirillova, E.N.; Andersson, A.; Sheesley, R.J.; Kruså, M.; Praveen, P.S.; Budhavant, K.; Safai, P.D.; Rao P.S.P.; Gustafsson, Ö.
2013 | J. Geophys. Res.-Atmos. | 118 (614-626)

Water-soluble organic carbon (WSOC) is typically a large component of carbonaceous aerosols with a high propensity for inducing cloud formation. The sources of WSOC, which may be both of primary and secondary origins, are in general poorly constrained. This study assesses the concentrations and dual-carbon isotope (14C and 13C) signatures of South Asian WSOC during a 15-month continuous campaign in 2008-2009. Total suspended particulate matter samples were collected at Sinhagad (SINH) India and at the Maldives Climate Observatory at Hanimaadhoo (MCOH). Monsoon-driven meteorology yields significant WSOC concentration differences between the dry winter season (0.94±0.43 ug m-3 MCOH and 3.6±2.3 ug m-3 SINH) and the summer monsoon season (0.10±0.04 ug m-3 MCOH and 0.35±0.21 ug m-3 SINH). Radiocarbon-based source apportionment of WSOC shows the dominance of biogenic/biomass combustion sources but also a substantial anthropogenic fossil-fuel contribution (17±4% MCOH and 23±4% SINH). Aerosols reaching MCOH after long-range over-ocean transport were enriched by 3-4‰ in del13C-WSOC relative to SINH. This is consistent with particle-phase aging processes influencing the del13C-WSOC signal in the South Asian regional receptor atmosphere.

Brown Clouds over South Asia: Biomass or Fossil Fuel Combustion?

Gustafsson, Ö.; Kruså, M.; Zencak, Z.; Sheesley, R.J.; Granat, L.; Engström, E.; Praveen, P.S.; Rao, P.S.P.; Leck, C.; Rodhe, H.
2009 | Science | 323 (495-498)

Carbonaceous aerosols cause strong atmospheric heating and large surface cooling that is as important to South Asian climate forcing as greenhouse gases, yet the aerosol sources are poorly understood. Emission inventory models suggest that biofuel burning accounts for 50 to 90% of emissions, whereas the elemental composition of ambient aerosols points to fossil fuel combustion. We used radiocarbon measurements of winter monsoon aerosols from western India and the Indian Ocean to determine that biomass combustion produced two-thirds of the bulk carbonaceous aerosols, as well as one-half and two-thirds of two black carbon subfractions, respectively. These constraints show that both biomass combustion (such as residential cooking and agricultural burning) and fossil fuel combustion should be targeted to mitigate climate effects and improve air quality.

Source apportionment of elevated wintertime PAHs by compound-specific radiocarbon analysis.

Sheesley, R.J.; Kruså, M.; Krecl, P.; Johansson, C.; Gustafsson, Ö.
2008 | Atmos. Chem. Phys. Discuss. | 8 (20901-20924)

Natural abundance radiocarbon analysis facili- tates distinct source apportionment between contemporary biomass/biofuel (14C alive) versus fossil fuel (14C dead) combustion. Here, the first compound-specific radiocar- bon analysis (CSRA) of atmospheric polycyclic aromatic hydrocarbons (PAHs) was demonstrated for a set of sam- ples collected in Lycksele, Sweden a small town with fre- quent episodes of severe atmospheric pollution in the win- ter. Renewed interest in using residential wood combus- tion (RWC) means that this type of seasonal pollution is of increasing concern in many areas. Five individual/paired PAH isolates from three pooled fortnight-long filter collec- tions were analyzed by CSRA: phenanthrene, fluoranthene, pyrene, benzob+kfluoranthene and indenocdpyrene plus benzoghiperylene; phenanthrene was the only compound also analyzed in the gas phase. The measured 14C for PAHs spanned from 138.3 to 58.0. A simple isotopic mass balance model was applied to estimate the fraction biomass (fbiomass) contribution, which was constrained to 7187% for the individual PAHs. Indenocdpyrene plus benzoghiperylene had an fbiomass of 71%, while fluoran- thene and phenanthrene (gas phase) had the highest biomass contribution at 87%. The total organic carbon (TOC, de- fined as carbon remaining after removal of inorganic car- bon) fbiomass was estimated to be 77%, which falls within the range for PAHs. This CSRA data of atmospheric PAHs es- tablished that RWC is the dominating source of atmospheric PAHs to this region of the boreal zone with some variations among RWC contributions to specific PAHs.

Pre-treatment of cellulose by cellobiose dehydrogenase increases the degradation rate by hydrolytic cellulases

Kruså, M.; Lennholm, H.; Henriksson, G.
2007 | Cell. Chem. Technol. | 41 (2-3) (105-111)

Oxidative Cellulose Biodegradation by Cellobiose Dehydrogenase from Phanerochaete chrysosporium. A model compound study

Kruså, M.; Henriksson, G.; Johansson, G.; Reitberger, T.; Lennholm, L.
2005 | Holzforschung | 59 (3) (263-268)

A reversed-phase high-performance liquid chromatographic method for the determination of soya bean proteins in bovine milks

Kruså, M.; Torre, M.; Marina, M.L.
2000 | Anal. Chem. | 72 (8) (1814-1818)

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106 91 Stockholm

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