Division of Environmental Engineering, School of Energy, Environmental, Biological, and Medical Engineering, University of Cincinnati, Ohio 45221, USA.
Environ Sci Technol. 2013 May 7;47(9):4619-27. doi: 10.1021/es400360v. Epub 2013 Apr 17.
The aerobic biodegradation kinetics and mineralization of six petrodiesel/soybean-biodiesel blends (B0, B20, B40, B60, B80, and B100), where B100 is 100% biodiesel, were investigated by acclimated cultures. The fatty acid methyl esters (FAMEs) of biodiesel were found to undergo rapid abiotic transformation in all experiments. The C10-C21 n-alkanes of petrodiesel were metabolized at significantly higher microbial utilization rates in the presence of biodiesel. The rates of mineralization of the blends were also enhanced in the presence of biodiesel; yet a similar enhancement in the extent of mineralization was not observed. Abiotic fuel-blends/aqueous-phase equilibration experiments revealed that the FAMEs of biodiesel were capable of cosolubilizing the n-alkanes of petrodiesel, a mechanism that fully explains the faster utilization and mineralization kinetics of petrodiesel in the presence of biodiesel without necessarily enhancing the extent of biomineralization. The biodegradation of six targeted aromatic compounds present in petrodiesel was also influenced by the amount of biodiesel in a blend. While toluene, o-xylene, and tetralin were not degraded in the B0 and B20 treatments, all of the targeted aromatic compounds were degraded to below detection limits in the B40 and B80 treatments. Biomass acclimated to B60, however, was unable to degrade most of the aromatic compounds. These results indicate that the amount of biodiesel in a blend significantly affects the absolute and relative abundance of the dissolved and bioavailable constituents of biodiesel and petrodiesel in a way that can considerably alter the biodegrading capacity of microbial cultures.
采用驯化培养物研究了六种石油柴油/大豆生物柴油混合物（B0、B20、B40、B60、B80 和 B100）的好氧生物降解动力学和矿化作用，其中 B100 是 100%生物柴油。生物柴油的脂肪酸甲酯（FAME）在所有实验中均迅速发生非生物转化。在存在生物柴油的情况下，石油柴油的 C10-C21 正构烷烃以更高的微生物利用率被代谢。在存在生物柴油的情况下，混合物的矿化速率也得到了增强；然而，并没有观察到矿化程度的类似增强。非生物燃料混合物/水相平衡实验表明，生物柴油的 FAME 能够共溶石油柴油的正构烷烃，这一机制完全解释了在存在生物柴油的情况下石油柴油更快的利用和矿化动力学，而不必增强生物矿化程度。在混合物中生物柴油的量也影响了六种目标芳烃化合物在石油柴油中的生物降解。虽然甲苯、邻二甲苯和四氢萘在 B0 和 B20 处理中没有降解，但在 B40 和 B80 处理中所有目标芳烃化合物均降解至检测限以下。然而，适应 B60 的生物量无法降解大多数芳烃化合物。这些结果表明，混合物中生物柴油的量以一种可以显著改变微生物培养物生物降解能力的方式，显著影响生物柴油和石油柴油中溶解的和生物可利用成分的绝对和相对丰度。
