Environ Sci Technol. 2018 Dec 18;52(24):14496-14507. doi: 10.1021/acs.est.8b03345. Epub 2018 Dec 4.
Biodiesel engines produce several intermediate species, which can potentially harm the human health. The concentration of these species and their health risk potential varies depending on engine technology, fuel, and engine operating condition. In this study, experiments were performed on a large number of engines having different configurations (emissions norms/fuel used), which were operated at part load/full load using B20 (20% v/v biodiesel blended with mineral diesel) and mineral diesel. Experiments included measurement of gaseous emissions, and physical, chemical, and biological characterization of exhaust particulate matter (PM). Chemical characterization of PM was carried out for detecting polycyclic aromatic hydrocarbons (PAH's) and PM bound trace metals. The biological toxicity associated with PM was assessed using human embryonic kidney 293T cells (HEK 293T). The mutagenic potential of the PM was tested at three different concentrations (500, 100, and 50 μg/mL) using two different Salmonella strains, TA98 and TA100, with and without liver S9 metabolic enzyme fraction. PM samples exhibited cytotoxic effect on HEK 293T cells (IC < 100 μg/mL) and there was significant potential for reactive oxygen species (ROS) generation. Comparison of different engines showed that modern engines (Euro-III and Euro-IV compliant) produced relatively cleaner exhaust compared to older engines (Euro-II compliant). Biodiesel-fueled engines emitted lower number of particles compared to diesel-fueled engines. However, chemical characterization revealed that biodiesel-fueled engines exhaust PM contained several harmful PAHs and trace metals, which affected the biological activity of these PM, as reflected in the biological investigations. Mutagenicity and cytotoxicity of PM from biodiesel-fueled engines were relatively higher compared to their diesel counterparts, indicating the need for exhaust gas after-treatment.
生物柴油发动机产生多种中间物质，这些物质可能会对人类健康造成危害。这些物质的浓度及其潜在的健康风险因发动机技术、燃料和发动机运行条件而异。在这项研究中，对具有不同配置（排放标准/使用的燃料）的大量发动机进行了实验，这些发动机在部分负荷/满载下使用 B20（20%v/v 生物柴油与矿物柴油混合）和矿物柴油运行。实验包括测量气态排放物，以及对废气颗粒物（PM）进行物理、化学和生物特性分析。PM 的化学特性分析是为了检测多环芳烃（PAH）和 PM 结合的痕量金属。使用人胚肾 293T 细胞（HEK 293T）评估与 PM 相关的生物毒性。PM 的致突变潜能在三个不同浓度（500、100 和 50μg/mL）下使用两种不同的沙门氏菌菌株 TA98 和 TA100 进行了测试，同时使用和不使用肝脏 S9 代谢酶部分。PM 样品对 HEK 293T 细胞表现出细胞毒性作用（IC <100μg/mL），并且具有显著的产生活性氧（ROS）的潜力。对不同发动机的比较表明，与旧发动机（符合 Euro-II 标准）相比，现代发动机（符合 Euro-III 和 Euro-IV 标准）产生的废气相对清洁。与柴油发动机相比，生物柴油发动机排放的颗粒数量较少。然而，化学特性分析表明，生物柴油发动机废气 PM 中含有几种有害的 PAH 和痕量金属，这影响了这些 PM 的生物活性，反映在生物研究中。与柴油发动机相比，生物柴油发动机排放的 PM 的致突变性和细胞毒性相对较高，这表明需要进行废气后处理。
