Polycyclic aromatic hydrocarbons are of great concern due to their persistence, bioaccumulation and toxic properties. The occurrence, source and ecological risk assessment of 26 polycyclic aromatic hydrocarbons in industrial and agricultural effluents affecting the Wadi El Bey watershed were investigated by means of gas chromatographic/mass spectrometric analysis (GC/MS). Total PAHs (∑ 26 PAH) ranged from 1.21 to 91.7 µg/L. The 4- and 5-ring compounds were the principal PAHs detected in most of 5 sites examined. Diagnostic concentration ratios and molecular indices were performed to identify the PAH sources. Results show that PAHs could originate from petrogenic, pyrolytic and mixed sources. According to the ecotoxicological assessment, the potential risk associated with PAHs affecting agricultural and industrial effluents ranged from moderate to high for both aquatic ecosystem and human health. The toxic equivalency factor (TEF) approach indicated that benzo[a]pyrene and benz[a]anthracene were the principal responsible for carcinogenic power of samples.
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http://dx.doi.org/10.1007/s10653-018-0075-2 | DOI Listing |
Sci Adv
January 2025
Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan.
The pursuit of boron-based organic compounds with multiresonance (MR)-induced thermally activated delayed fluorescence (TADF) is propelled by their potential as narrowband blue emitters for wide-gamut displays. Although boron-doped polycyclic aromatic hydrocarbons in MR compounds share common structural features, their molecular design traditionally involves iterative approaches with repeated attempts until success. To address this, we implemented machine learning algorithms to establish quantitative structure-property relationship models, predicting key optoelectronic characteristics, such as full width at half maximum (FWHM) and main peak wavelength, for deep-blue MR candidates.
View Article and Find Full Text PDFChemphyschem
January 2025
IISER Bhopal: Indian Institute of Science Education and Research Bhopal, Department of Chemistry, Bhopal Bypass Road, Bhauri, 462066, Bhopal, INDIA.
Aggregation-caused quenching (ACQ) reduces luminescence and compromises brightness in solid-state displays, necessitating strategies to mitigate its effects for enhanced performance. This study presents cost-effective method to mitigate ACQ of pyrene by co-assembling polycyclic aromatic hydrocarbons within low molecular weight gelator. Synthesized from readily available materials-cholesteryl chloroformate and pentaerythritol-in one-step reaction, gelator incorporates four cholesteryl units, reported to promote robust supramolecular gels in various solvents.
View Article and Find Full Text PDFACS Earth Space Chem
January 2025
School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, U.K.
2-Cyanoindene is one of the few specific aromatic or polycyclic aromatic hydrocarbon (PAH) molecules positively identified in Taurus molecular cloud-1 (TMC-1), a cold, dense molecular cloud that is considered the nearest star-forming region to Earth. We report cryogenic mid-infrared (550-3200 cm) and visible (16,500-20,000 cm, over the ← electronic transition) spectra of 2-cyanoindene radical cations (2CNI), measured using messenger tagging (He and Ne) photodissociation spectroscopy. The infrared spectra reveal the prominence of anharmonic couplings, particularly over the fingerprint region.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Chemistry, Indian Institute of Technology, Guwahati 781039, India.
Charge transfer (CT) states in polycyclic aromatic hydrocarbons play crucial roles in determining their electronic properties and their potential applications in organic electronics. In this work, we investigate the nature of the excited states in monomers and π-stacked dimers of azulene-fused naphthalene and anthracene systems, focusing on the interplay between structure and excited-state properties. Four different isomers for azulene-fused naphthalene (, , , and ) and anthracene (, , , and ) are considered.
View Article and Find Full Text PDFEnviron Pollut
January 2025
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
Natural attenuation represents a significant ecosystem function for mitigating the quantity and toxicity of polycyclic aromatic hydrocarbons (PAHs) through both abiotic and biotic dissipation processes. This study systematically investigated abiotic and biotic dissipation of phenanthrene (Phe) and benzo[a]pyrene (BaP) in four soils over 360 days, using CSIA to quantitatively analyze δ³C changes and demonstrate biodegradation. The results indicated that extractable Phe was primarily attenuated via biodegradation (65% - 81%), as revealed by CSIA, with the δ³C changes ranging from 2.
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