Influence of the Anaerobic Biodegradation of Different Types of Biodiesel on the Natural Attenuation of Benzene

Abstract

In the present research work, different types of biodiesel were produced by a homogeneous alkali transesterification reaction using soybean oil, pork lard, and castor bean oil as raw materials, to evaluate how their different compositions may affect the biodegradability, namely, in the presence of benzene. Biodiesel was characterized according to the European standard EN 14214. The anaerobic biodegradation of the different types of biodiesel was examined as well as its influence on the biodegradation of benzene. Analyses were performed to determine the volume of methane (directly related to the anaerobic biodegradation of bio-diesel), the concentration of benzene over time, and the production of organic acids. The results showed methane production resulting from the anaerobic degradation of all biodiesel types. The differences between the degradation behavior of each fuel were negligible, contrary to what was expected; however, the amount of methane produced was low due to nutrient limitations. This fact was confirmed by the organic acid analysis as well as by the addition of new media. Anaerobic benzene biodegradation was found to be negatively impacted by the presence of all biodiesel types on average; therefore, the results of this study may impact management of sites that contain biodiesel and fuel hydrocarbon contamination.

Anaerobic Biodegradation of Ethylic and Methylic Biodiesel and Their Impact on Benzene Degradation

“…4 and those for biodiesel alone (from Section 3.2) suggest that biodiesel appears to be more readily biodegradable under anaerobic conditions than benzene. The results of this study are similar to previous studies that used soybean oil biodiesel [10,12]. Although this appears to be the case, future tests should be performed on the LCFA uptake profiles to further elucidate the relative biodegradability of the substrates used in this study.…”

“…The differences observed between these oils are expected since they are very heterogeneous and depend upon the previous domestic use. The higher kinematic viscosity of waste frying oil biodiesel may cause lower bioavailability and consequently lower biodegradation rates compared to other types of biodiesel, as was seen in other studies . Oxidation stability was very low in all cases.…”

“…The higher kinematic viscosity of waste frying oil biodiesel may cause lower bioavailability and consequently lower biodegradation rates compared to other types of biodiesel, as was seen in other studies [10,12]. Oxidation stability was very low in all cases.…”

“…The three types of biodiesel that were produced have different characteristics: Both SMB and SEB show high ester content, low kinematic viscosity, and low water content while WFEB shows a slight lower ester content, higher kinematic viscosity and acid value, and extremely high water content. As previously stated, biodiesel with higher viscosities may interfere with its biodegradation due to decreasing bioavailability .…”

Integrated Anaerobic-Aerobic Biodegradation of Multiple Contaminants Including Chlorinated Ethylenes, Benzene, Toluene, and Dichloromethane

“…Hydroxylation, methylation, and carboxylation are possible mechanisms of anaerobic benzene degradation (Foght 2008; Weelink et al 2010; Vogt et al 2011), and Azoarcus and Desulfobacterales - and Coriobacteriaceae -related bacteria are identified as anaerobic benzene degraders (Kasai et al 2006; Noguchi et al 2014). Although case studies on anaerobic biodegradation are available (e.g., Vogt et al 2011; Borges et al 2014), anaerobic benzene degraders have been identified in recent years, and anaerobic biodegradation of benzene requires two or more cooperative microbes (Vogt et al 2011). This leads to a wider application of aerobic biodegradation of benzene.…”