Biodegradable diesel

In addition to greenhouse benefits, biodiesels offer environmental advantages over conventional diesel. Biodiesels produce similar NO, emissions to conventional diesel, fuel but less particulate matter. Biodiesel is more biodegradable that conventional diesel making any spills less damaging in sensitive areas. In general biodiesel provides more lubrication to the fuel system than low-sulfur diesel. 

Margesin R, F Schinner (1997) Efficiency of indigenous and inoculated cold-adapted soil microorganisms for biodegradation of diesel oil in alpine oils. Appl Environ Microbiol 63 2660-2664. 

Due to its particular composition, biodiesel is biodegradable and allows reduced emissions, in terms of particulates and polycyclic aromatic hydrocarbons. Instead, the results of the combustion of biodiesel are contentious in relation to so-called NOx emissions, where it has been observed that such emissions are more or less increased, with respect to conventional diesel, depending on the characteristics of the engine in which it is used ... 

The most broadly studied organic nitrogen compound is probably quinoline however, most studies report biodegradation. As we have seen from Table 14, quinoline is representative of the organonitrogen compounds present in the diesel cut. Its transformation has been studied in both, anaerobic and aerobic conditions. Several metabolic pathways have been proposed to explain the aerobic transformations however, no pathway has been proposed for quinoline metabolism under anaerobic conditions. 

Hydrocarbon Microbiology biodegradation mechanisms of oil products (gasoline, kerosene, diesel, etc.), pyrolysis, polycyclic aromatic hydrocarbons, chlorinated solvents, and ether fuels refining processes (e.g., oil product microbial desulfurization) and oil production processes (e.g., bacterial corrosion). 

Jhanson R, Ackerman CE, Scow KM (1999) Biodegradation of methyl ter/-butyl ether by abacterial pure culture. Appl Environ Microbiol 65 4788-4792 Kanaly RA, Bartha R, Watanabe K, Harayama S (2000) Rapid mineralization of benzo[a]pyrcnc by a microbial consortium growing on diesel fuel. Appl Environ Microbiol 66 4205-4211... 

Davis, G. B., Johnston, C. D., Patterson, B. M., Bucer, C. and Dennett, M., 1988, Estimation of Biodegradation Rates Using Respiration Tests during In-Situ Bioremediation of Weathered Diesel NAPL Ground Water Monitoring Remediation, Spring, pp. 122-132. 

Apart from being used as bio-diesel , fatty acid esters, which are obtained from fatty acids and alcohols, are becoming increasingly interesting as biodegradable replacements for mineral oils. In some application areas such as chain-saw oil, gearbox oils, hydraulic oils and lubricants for crude oil production these oleochemical products have already proved themselves. 

Wilson and Madsen [152] used the metabolic pathway for bacterial naphthalene oxidation as a guide for selecting l,2-dihydroxy-l,2-dihydronaphthalene as a unique transient intermediary metabolite whose presence in samples from a contaminated field site would indicate active in situ naphthalene biodegradation (Fig. 26). Naphthalene is a component of a variety of pollutant mixtures. It is the major constituent of coal tar [345], the pure compound was commonly used as a moth repellant and insecticide [345], and it is a predominant constituent of the fraction of crude oil used to produce diesel and jet fuels [346]. Prior studies at a coal tar-contaminated field site have focused upon contaminant transport [10,347], the presence of naphthalene catabolic genes [348, 349], and non-metabolite-based in situ contaminant biodegradation [343]. 

The age of diesel oil in the subsurface soil environment can be determined by utilizing the fact that the composition of the diesel oil (the ratio between -alkanes and isoprenoids) changes due to biodegradation. In one study, the ratio of C , to pristane was highly correlated with the residence time of diesel fuel at 12 test locations (Christensen et al 1993). 

Many new sugar based products present the advantage of being non-toxic and biodegradable. The products resulting from the telomerization of 1 with appropriate nucleophiles such as alcohols, amines, water, or carbon dioxide serve generally as useful intermediates in the synthesis of various natural products and fine chemicals [60-63], as precursors for plasticizer alcohols [56, 64], components of diesel fuels [65], surfactants [11, 66], corrosions inhibitors, and non-volatile herbicides [67]. 

The PetroClean bioremediation system treats biodegradable contaminants (i.e., gasoline, diesel fuel, aviation fuel, solvents, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), total petroleum hydrocarbons (TPH), and other organic compounds in soils and groundwater. 

Biodiesel is a olean burning alternative fuel produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to oreate a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, non-toxic, and essentially free of sulfur and aromatics. 

Biofuels are obtained from renewable sources and, when they are combusted, generate only as much CO2 as withdrawn form atmosphere by photosynthesis. Less carbon dioxide is formed in the course of combustion than by the equivalent amount of crude oil distillate fuel, for example diesel fuel. In addition, very little sulfur dioxide is formed. Of course, biofuels are biodegradable. 

Biodegradation can be accelerated in a prepared bed reactor with forced aeration. These reactors (Figure 1.2) are used at many Superfund sites for bioremediation of PAHs and BTEX (benzene, toluene, ethylbenzene, and xylene) (Alexander, 1994). This method, with recirculating leachate, was used to reduce the average total petroleum hydrocarbon concentration in a diesel-contaminated soil from 6200 mg/kg dry soil to 280 mg/kg in approximately 7 weeks (Reynolds et al., 1994). A bed reactor with forced aeration was also used to treat 115 000 m3 of soil contaminated with bunker C fuel oil (Compeau, Mahaffey Patras, 1991) and 23 000 m3 of soil contaminated with gasoline and fuel oil (Block, Clark Bishop, 1990). 

Many hydrocarbons bind quite tightly to soil components, and are thereby less available to microbial degradation. Intrinsic biodegradation occurs, but it usually only removes the lightest refined products, such as gasoline, diesel and jet fuel. Active intervention is typically required. Usually the least expensive approach is in situ remediation, typically with the addition of nutrients, and the attempted optimization of moisture and oxygen by tilling. 

Underground storage tanks and piping should incorporate a leak detection system. While biodiesel is biodegradable, fuel additives or diesel fuel may be added to biodiesel which will make spills a health concern if they find their way into the water system. There is no need for leak detection around the dispenser. 

Biodiesel is believed to be a promising alternative fuel to substitute petroleum-derived diesel fuel in diesel engines, and essentially no engine modifications are required to substitute biodiesel for diesel fuel. In addition, biodiesel is better than diesel fuel in terms of sulfur content, flash point, aromatic content, and biodegradability (1). Research on the commercial application of biodiesel has therefore been started in European countries, the United States, and Japan (2,3). 

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