Palm oil biodiesel: An assessment of PAH emissions, oxidative potential and ecotoxicity of particulate matter

This work assessed the impact of fuelling an automotive engine with palm biodiesel (pure, and two blends of 10% and 20% with diesel, B100, B10 and B20, respectively) operating under representative urban driving conditions on 17 priority polycyclic aromatic hydrocarbon (PAH) compounds, oxidative potential of ascorbic acid (OPAA), and ecotoxicity through Daphnia pulex mortality test. PM diluted with filtered fresh air (WD) gathered in a minitunel, and particulate matter (PM) collected directly from the exhaust gas stream (W/oD) were used for comparison. Results showed that PM collecting method significantly impact PAH concentration. Although all PAH appeared in both, WD and W/oD, higher concentrations were obtained in the last case. Increasing biodiesel concentration in the fuel blend decreased all PAH compounds, and those with 3 and 5 aromatic rings were the most abundant. Palm biodiesel affected both OPAA and ecotoxicity. While B10 and B20 exhibited the same rate of ascorbic acid (AA) depletion, B100 showed significant faster oxidation rate during the first four minutes and oxidized 10% more AA at the end of the test. B100 and B20 were significantly more ecotoxic than B10. The lethal concentration LCSO for B10 was 6.13 mg/L. It was concluded that palm biodiesel decreased PAH compounds, but increased the oxidative potential and ecotoxicity. (C) 2020 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Automated summary

The study assessed the impact of using palm biodiesel on 17 priority PAH compounds, oxidative potential, and ecotoxicity under urban driving conditions. Results showed that increasing biodiesel concentration decreased PAH compounds but increased oxidative potential and ecotoxicity. Different biodiesel blends had varying effects on ascorbic acid depletion and ecotoxicity.