eliminated, S n eliminated, S n the Archie saturation exponent tended to increase with the increase of , and was recommended H between 20 and 30.

Shi, D., Bera, G., Knap, A.H., Quigg, A., Al Atwah, I., Gold-Bouchot, G., Wade, T.L., 2020. A mesocosm experiment to determine half-lives of individual hydrocarbons in simulated oil spill scenarios with and without the dispersant, Corexit. Marine Pollution Bulletin 151, 110804.

http://www.sciencedirect.com/science/article/pii/S0025326X19309609 Here, we report results from a 15-day mesocosm experiment examining changes in estimated oil equivalents n n n (EOEs), -alkanes ( -C to -C ), polycyclic aromatic hydrocarbons (PAHs) and petroleum biomarkers. Water 10 35 accommodated fractions (WAF) of oil and diluted chemically enhanced WAF(DCEWAF) were prepared and n concentrations of oil residues determined on day 0, 3 and 15, respectively. Significant removals of -alkane and n n n PAHs were observed starting from day 3. The -C /pristane and -C /phytane ratios suggested that the - 17 18 alkane removal was due to biodegradation in the mesocosms. The ratios of C2-dibenzothiophenes/C2- phenanthrenes (D2/P2) and C3-dibenzothiophenes/C3-phenanthrenes (D3/P3) were found to be stable through n the experiment. DCEWAF treatment had longer half-lives for most -alkanes but shorter half-lives for most PAHs than the WAFtreatment. Most petroleum biomarkers were stable throughout the experiment. However, depletion of TAS (tricyclic aromatic steroids) was observed on day 15 of DCEWAF treatment.

Shi, X., Qiu, X., Cheng, Z., Chen, Q., Rudich, Y., Zhu, T., 2020. Isomeric identification of particle-phase organic nitrates through gas chromatography and time-of-flight mass spectrometry coupled with an electron capture negative ionization source. Environmental Science &Technology 54, 707-713.

https://doi.org/10.1021/acs.est.9b05818 Organic nitrates (ONs) are an important component of secondary organic aerosols that play significant roles in atmospheric chemical processes such as ozone formation and as a reservoir of nitrogen oxides (NO ). However, x hindered by the availability of analytical techniques, characteristics of ON molecules remain unclear in regions influenced by anthropogenic volatile organic compounds (VOCs) and pollution. In this study, we achieved isomeric identification of particle-phase ONs in such regions. Using gas chromatography and time-of-flight mass spectrometry with an electron capture negative ionization source, we established a systematic procedure for screening unknown ONs in fine particulate matter (PM) collected in Beijing based primarily on the - - - characteristic fragment ions of NO and [M - NO ] /[M - NO - H ] . We found 78 ON candidates, 12 of which 2 2 2 2 were confirmed using synthesized standards. Seventy-three of these detected ONs might originate from anthropogenic VOC precursors especially alkenes. Significantly, we observed two isomers generated from straight-chain 1-alkenes, namely, 2-hydroxy-1-nitrate and 1-hydroxy-2-nitrate. The signal ratios of the two isomers suggested that these hydroxy nitrates are mainly produced photochemically rather than through nighttime reactions. This study provides a promising method for identifying ONs in atmospheric PM and elucidating their formation pathways.

Shoukry, A.E., El-Banbi, A.H., Sayyouh, H., 2020. Enhancing asphaltene precipitation modeling by cubic-PR solid model using thermodynamic correlations and averaging techniques. Petroleum Science 17, 232 - 241.

https://doi.org/10.1007/s12182-019-00377-1 Cubic equation-of-state solid models are one of the most widely used models to predict asphaltene precipitation behavior. Thermodynamic parameters are needed to model precipitation under different pressures and temperatures and are usually obtained through tuning with multi asphaltene onset experiments. For the purpose of enhancing the cubic Peng - Robinson solid model and reducing its dependency on asphaltene experiments, this paper tests the use of aromatics and waxes correlations to obtain these thermodynamic parameters. In addition, weighted averages between both correlations are introduced. The averaging is based on reported saturates, aromatics, resins, asphaltene (SARA) fractions, and wax content. All the methods are tested on four oil samples, with previously published data, covering precipitation and onset experiments. The proposed wax-