No abstract

Increased economic activity in the Arctic may increase the risk of oil spills. Yet, little is known about the degradation of oil spills by solar radiation and the impact of nutrient limitation on oil biodegradation under Arctic conditions. We deployed adsorbents coated with thin oil films for up to 4 months in a fjord in SW Greenland to simulate and investigate in situ biodegradation and photo-oxidation of dispersed oil droplets. Oil compound depletion by dissolution, biodegradation, and photo-oxidation was untangled by gas chromatography–mass spectrometry-based oil fingerprinting. Biodegradation was limited by low nutrient concentrations, reaching 97% removal of nC13–26-alkanes only after 112 days. Sequencing of bacterial DNA showed the slow development of a bacterial biofilm on the oil films predominated by the known oil degrading bacteria Oleispira, Alkanindiges and Cycloclasticus. These taxa could be related to biodegradation of shorter-chain (≤C26) alkanes, longer-chain (≥C16) and branched alkanes, and polycyclic aromatic compounds (PACs), respectively. The combination of biodegradation, dissolution, and photo-oxidation depleted most PACs at substantially faster rates than the biodegradation of alkanes. In Arctic fjords during summer, nutrient limitation may severely delay oil biodegradation, but in the photic zone, photolytic transformation of PACs may play an important role.

Catalytic fast pyrolysis (CFP) is a technology option for producing advanced biofuels from hydrocarbon-rich biocrude intermediates. The relatively high oxygen content of biocrudes compared to petroleum intermediates increases hydrogen consumption...

a b s t r a c t Available online xxxxKhuzestan, Iran is heavily industrialised with petrochemical and refinery companies. Herein, sediment and soil samples were collected from Hendijan coast, Khore Mosa and Arvandroud River. The CHEMSIC (CHEmometric analysis of Selected Ion Chromatograms) method was used to assign the main sources of polycyclic aromatic hydrocarbon (PAH) pollution. A four-component principal component analysis (PCA) model was obtained. While principal component 1 (PC1) was related to the total concentration of PAHs, the remaining PCs described three distinct sources: PC2 and PC3 collectively differentiate between weathered petrogenic and pyrogenic, and PC4 is indicative for a diagenetic input. The sources of PAHs in the Arvandroud River were mainly relatively fresh oil with some samples corresponding to a weathered oil input. Further, perylene (indicator for diagenetic source) was identified. Samples from Khore Mosa revealed a mixture with high proportions of high-molecular-weight PAHs, indicating a pyrogenic/weathered petrogenic source. Samples from Hendijan coast contained low relative concentrations of PAHs, thus only little information on pollution sources.

Catalytic fast pyrolysis (CFP) biocrudes can comprise up to 30 wt % of oxygen content in compounds such as polyphenols, acids, carbonyls, and anhydrosugars and thus require upgrading by, e.g., hydrotreatment, to produce transport fuels. The chemical characterization of phenolic and acidic compounds in biocrudes is of great importance to optimize the CFP process. In this study, an analytical workflow is proposed for nontarget chemical fingerprinting analysis of CFP biocrudes using supercritical fluid chromatography high-resolution mass spectrometry (SFC-HRMS) with negative electrospray ionization (ESI − ), followed by multivariate data analysis. The method was developed and tested on five biocrude samples from loblolly pine (Pinus taeda) with varying oxygen content (14.9−28.8 wt % wet basis) due to different CFP conditions. The pixel-based analysis displayed chemical variation between all samples. Twenty-four regions of interest were tentatively identified, including mono-and polyphenols, fatty acids, and methylated and methoxylated phenols. The identification workflow and MS/MS analysis were prioritized on the peaks with the highest relative concentration. The developed SFC-ESI − -HRMS method shows high repeatability and analyzed oxygen-containing compounds with hydroxyl and/or carboxyl moieties in combination with other moieties of up to 400 Da.