Impact of biodiesel on regulated and unregulated emissions, and redox and proinflammatory properties of PM emitted from heavy-duty vehicles

Karavalakis, Georgios; Gysel, Nicholas; Schmitz, Debra A.; Cho, Arthur K.; Sioutas, Constantinos; Schauer, James J.; Cocker, David R.; Durbin, Thomas D.

doi:10.1016/j.scitotenv.2017.01.187

Cited by 51 publications

(39 citation statements)

References 60 publications

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“…The six redox-active transition metals listed above were weakly to moderately correlate with both the DTT and the ROS assay activities (r of 0.25 to 0.46 for DTT and r 2 of 0.18 to 0.50 for ROS (Table 1). These results, though the sample number is small, contrast in-part to some previously reported chassis dynamometer data where both ROS and DTT assays showed good correlations with the redox-active transition metals (Karavalakis et al, 2017;Verma et al, 2010). Strong correlations were seen between the total sum of water-extractable metals and ROS (r 2 of 0.85) and DTT (r 2 of 0.92).…”

Section: Water Extractable Metalscontrasting

confidence: 99%

Physical, chemical, and toxicological characteristics of particulate emissions from current technology gasoline direct injection vehicles

Yang

Roth

Ruehl

et al. 2019

Science of The Total Environment

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• Cold-start dominated the production of black carbon and particle number emissions. • Elevated PM emissions during the hard accelerations of the test cycle • Overall, GDI PM samples showed that acute exposure toxicity was low for ROS generation and inflammatory potential. • Correlation of trace metals and oxidative potential suggests a role for insoluble particles in inducing oxidative stress.

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Section: Water Extractable Metalscontrasting

confidence: 99%

Physical, chemical, and toxicological characteristics of particulate emissions from current technology gasoline direct injection vehicles

Yang

Roth

Ruehl

et al. 2019

Science of The Total Environment

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“…Based on this hypothesis, the OP DTT has been widely used to predict adverse health outcomes from PM exposure. However, no conclusive associations have been found between OP DTT and cellular ROS generation measured by the macrophage ROS assay and H2DCFDA assay [68,85,86]. Also, contradictory results have been reported between OP DTT and gene expressions of oxidative stress and inflammation-associated biomarkers in cellular assays.…”

Section: The Correlation Between Biological Responses and Op Dttmentioning

confidence: 99%

“…A strong correlation was observed between OP DTT and the expression of heme oxygenase-1 (HMOX-1) (a relevant biomarker for oxidative stress) in BEAS-2B cells exposed to PM collected from the Los Angeles basin in California [87]. However, OP DTT was found not to be associated with the HMOX-1, but with the expression of tumor necrosis factor-alpha (TNF-α) (a pro-inflammatory cytokine) in a mouse macrophage cell line (Raw 264.7) after exposing to diesel and biodiesel emissions [86]. Additionally, a recent study by Tuet et al reported no significant correlations between OP DTT and cellular inflammatory biomarkers (i.e., TNF-α and interleukin-6) when exposed to various types of SOA in immortalized murine alveolar macrophages [68].…”

Section: The Correlation Between Biological Responses and Op Dttmentioning

confidence: 99%

Use of Dithiothreitol Assay to Evaluate the Oxidative Potential of Atmospheric Aerosols

et al. 2019

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Oxidative potential (OP) has been proposed as a useful descriptor for the ability of particulate matter (PM) to generate reactive oxygen species (ROS) and consequently induce oxidative stress in biological systems, which has been recognized as one of the most important mechanisms responsible for PM toxicity. The dithiothreitol (DTT) assay is one of the most frequently used techniques to quantify OP because it is low-cost, easy-to-operate, and has high repeatability. With two thiol groups, DTT has been used as a surrogate of biological sulfurs that can be oxidized when exposed to ROS. Within the DTT measurement matrix, OP is defined as the DTT consumption rate. Often, the DTT consumption can be attributed to the presence of transition metals and quinones in PM as they can catalyze the oxidation of DTT through catalytic redox reactions. However, the DTT consumption by non-catalytic PM components has not been fully investigated. In addition, weak correlations between DTT consumption, ROS generation, and cellular responses have been observed in several studies, which also reveal the knowledge gaps between DTT-based OP measurements and their implication on health effects. In this review, we critically assessed the current challenges and limitations of DTT measurement, highlighted the understudied DTT consumption mechanisms, elaborated the necessity to understand both PM-bound and PM-induced ROS, and concluded with research needs to bridge the existing knowledge gaps.

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“…Carbon dioxide (CO 2 ) is the most significant among all of the greenhouse gases emitted during the production of fossil-based energy (Li, Baležentis, Makutėnienė, Streimikiene, & Kriščiukaitienė, 2016). This CO 2 contributes to global warming as an emitted greenhouse gas -but using biodiesel in diesel engines reduces the CO 2 addition to the atmosphere (Datta & Mandal, 2017;Hasan & Rahman, 2017;Karavalakis et al, CONTACT Shahaboddin Shamshirband shahaboddin.shamshirband@tdt.edu.vn 2017). Burning fossil fuels in diesel engines has a negative impact on the environment and generates harmful pollutants (Singh et al, 2015;Yilmaz & Morton, 2011).…”

Section: Introductionmentioning

confidence: 99%

Application of ANNs, ANFIS and RSM to estimating and optimizing the parameters that affect the yield and cost of biodiesel production

Najafi

Ardabili

Shamshirband

et al. 2018

Engineering Applications of Computational Fluid Mechanics

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Biodiesel can easily be used as an alternative fuel in diesel engines. It is environmentally friendly and can be produced from low-cost feedstocks such as waste cooking oil (WCO). WCO contains a significant amount of free fatty acid, which is extracted by a two-step process of converting the free fatty acid by acid catalysis (H 2 S0 4) and converting the triglycerides using an NaOH catalyst. Currently, the major challenge for the industrial production of biodiesel is optimizing the yield while meeting American Society for Testing and Materials (ASTM) standards. In this study, experiments were performed to optimize the reaction conditions. The studied experimental parameters were the alcohol types (methanol, ethanol), the alcohol-to-oil molar ratio (AOMR; 3:1, 6:1, 9:1), the amount of catalyst (0.5, 1.0, 1.5 wt% of the oil), the temperature of the reaction (50, 60, 70, 80°C), the mixing intensity (300, 600, 900 rpm), and the reaction time (30, 60, 90 min). The biodiesel production yield (BPY) was optimized based on the experimental data. The optimum value of the BPY based on methanol is 95.92%, which is obtained at 73.80°C, with a reaction time of 74.02 min, an AOMR of 6.58:1, a catalyst concentration of 1.13 and a mixing intensity of 824.45 rpm. In the case of ethanol, the optimum BPY is 95.53%. which is obtained at 64.96°C, with a reaction time of 88.02 min, an AOMR of 7.005:1, a catalyst concentration of 1.25 and a mixing intensity of 592.18 rpm. These results of biodiesel production were confirmed by the experimental data.

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Impact of biodiesel on regulated and unregulated emissions, and redox and proinflammatory properties of PM emitted from heavy-duty vehicles

Cited by 51 publications

References 60 publications

Physical, chemical, and toxicological characteristics of particulate emissions from current technology gasoline direct injection vehicles

Physical, chemical, and toxicological characteristics of particulate emissions from current technology gasoline direct injection vehicles

Use of Dithiothreitol Assay to Evaluate the Oxidative Potential of Atmospheric Aerosols

Application of ANNs, ANFIS and RSM to estimating and optimizing the parameters that affect the yield and cost of biodiesel production

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