Biological degradation extraction

In both cases, the samples from contaminated sites were rinsed with a solvent to obtain an extract of contaminated transformer oil. The effects of biological degradation were investigated by using a commercial mixture of microorganisms and pure strain under aerobic and anaerobic condition. In the thermal method, a laboratory plasma system was used to decompose the contaminated transformer oil by a direct injection of the oil extract into the plasma system or by melting the extract samples with power plant fly ash in the plasma reactor. For the contaminated transformer oil both methods showed a destruction efficiency of 99.99% and the products of destruction were environmentally friendly. 

Several attempts have been reported by recovery teams to recover LNAPL by the use of vacuum wells set above the fluid surface. While these efforts have attained marginal success, several factors have been seen to interfere. Vacuum wells set in the vadose zone tend to encourage airflow from the surface downward through the soil, as well as to extract vapors. The result is often the enhancement of biological degradation near the wells, which tends to cause the well screens to become plugged with biomass. Routine maintenance of the wells is required to keep them functioning properly. 

Biological. Degradation by the microorganism Nocardia rhodochrous yielded ammonium ion and propionic acid, the latter being oxidized to carbon dioxide and water (DiGeronimo and Antoine, 1976). When 5 and 10 mg/L of acrylonitrile were statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, complete degradation was observed after 7 d (Tabak et al., 1981). Heukelekian and Rand (1955) reported a 5-d BOD value of 1.09 g/g which is 60.0% of the ThOD value of 1.81 g/g. 

T0411 Institute of Gas Technology Fluid Extraction—Biological Degradation T0421 InterBio, Hydrobac... 

T0411 Institute of Gas Technology, Fluid Extraction—Biological Degradation T0455 Kansas State University, Vibrorecovery T0456 Keller Environmental, Inc., Bioinjection T0467 KSE, Inc., AIR-H Process... 

Following biological degradation, the extract is exposed to photochemical degradation, which removes uranium from solution as polyuranate. The metals and uranium are captured in separate treatment steps, allowing for the separation of wastes into radioactive and nonradioactive waste streams. This treatment process does not create additional hazardous wastes and allows for the reuse of the contaminated soil. The technology has been the subject of bench-scale tests and is not currently commercially available. 

Rapeseed methyl ester (RME) is another alternative biofuel that can be used in diesel engines. RME has the advantages that it is renewable compared to diesel, non-toxic and less flammable compared with many other fuels, like ethanol. RME has the same cetane number, viscosity and density as diesel, contains no aromatic compounds and is biologically degradable with minor contamination in soil. RME can be produced from vegetable oils, but is mostly produced from rapeseed oil by pressing of the seeds or by extraction. Up to 3 tons of rapeseed can be produced from one hectare. The fatty acids in rapeseed oil are mostly oleic acid, linoleic acid and linolenic acid. The oil is pressed from the plant and after some purification allowed to react with methanol in the presence of potassium hydroxide as a catalyst, to produce a methyl ester, see Figure 6.6. 

In some applications degradation to lower molecular weight compounds raffier than gasification is desired. For example the extraction of oil-contaminated soil, which is not biologically degradable, leads to a mixture that can be treated in a conventional sewage treatment process [150, 151]. 

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