Cyclic volatile methylsiloxanes (cVMS) are used in personal care products and emitted to aquatic environments through wastewater effluents, and their bioaccumulation potential is debated. Here, a new bentho-pelagic version of the ACC-HUMAN model was evaluated for polychlorinated biphenyls (PCBs) and applied to cVMS in combination with measurements to explore their bioaccumulation behavior in a subarctic lake. Predictions agreed better with measured PCB concentrations in Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) when the benthic link was included than in the pelagic-only model. Measured concentrations of decamethylcyclopentasiloxane (D5) were 60 ± 1.2 (Chironomidae larvae), 107 ± 4.5 (pea clams Pisidium sp.), 131 ± 105 (three-spined sticklebacks: Gasterosteus aculeatus), 41 ± 38 (char), and 9.9 ± 5.9 (trout) ng g wet weight. Concentrations were lower for octamethylcyclotetrasiloxane (D4) and dodecamethylcyclohexasiloxane (D6), and none of the cVMS displayed trophic magnification. Predicted cVMS concentrations were lower than measured in benthos, but agreed well with measurements in fish. cVMS removal through ventilation was an important predicted loss mechanism for the benthic-feeding fish. Predictions were highly sensitive to the partition coefficient between organic carbon and water (K) and its temperature dependence, as this controlled bioavailability for benthos (the main source of cVMS for fish).
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http://dx.doi.org/10.1021/acs.est.7b03083 | DOI Listing |
Environ Sci Technol
January 2025
Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
Designing catalysts with both activity and stability remains a grand challenge for the removal of chlorinated volatile organic compounds (CVOCs) by catalytic oxidation. Herein, the Ru-Mn subnanometric species encapsulated in ZSM-5 zeolite (RuMn@Z) was synthesized. It shows that the 90% conversion of dichloromethane is as low as 320 °C, which is significantly lower than that of Ru@Z (350 °C) and the impregnation catalyst (RuMn/Z, 355 °C).
View Article and Find Full Text PDFBioelectrochemistry
January 2025
Department of Mechanical Engineering, Ajou University, South Korea. Electronic address:
Bloodstream bacterial infections, a major health concern due to rising sepsis rates, require prompt, cost-effective diagnostics. Conventional methods, like CO-based transduction, face challenges such as volatile metabolites, delayed gas-phase signaling, and the need for additional instruments, whereas electrochemical sensors provide rapid, sensitive, and efficient real-time detection. In this study, we developed a bioreceptor-free Prussian blue (PB) sensor platform for real-time bacterial growth monitoring in blood culture.
View Article and Find Full Text PDFFoods
December 2024
Jinan Fruit Research Institute, All China Federation of Supply & Marketing Co-Operatives, Jinan 250014, China.
Grey jujube ( Mill. cv. Huizao), a prominent cultivar from Xinjiang, China, is well known for its high nutritional value and medicinal benefits.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
College of Environment and Climate, Institute for Environmental and Climate Research, Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Jinan University, 51143, China.
Higher alkanes are a major class of intermediate volatile organic compounds (IVOCs) emitted by vehicles, which have been considered as important precursors of secondary organic aerosol (SOA) in urban area. Dynamometer experiments were conducted to characterize emissions from gasoline and diesel vehicles in China. Three types of higher alkanes, namely acyclic, cyclic, and bicyclic alkanes, were explicitly quantified through the novel proton transfer reaction time-of-flight mass spectrometer with NO ionization (NO PTR-ToF-MS) with time response of 1 second.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
School of Engineering, RMIT University, Melbourne, VIC 3000, Australia.
Entropy-Driven Ring-Opening Polymerisation represents an attractive mechanism to produce high-performance polymeric materials as it can be performed using neat, low-viscosity precursors and without the production of by-products or release of volatiles. Macrocyclic oligomers (MCOs) of polyether ketone ketone (PEKK) were synthesised and investigated as an method of forming this high-performance thermoplastic. Cyclic oligomers were successfully synthesised by pseudo-high dilution methods, and the reaction conditions were optimised through careful addition of starting materials and carbonate base selection.
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