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more likely to evaporate then biodegrade. Hydrocarbons deep in the soil are likely to biodegrade
<br />to a larger extent than evaporate as they are not exposed to the open environment. Light weight
<br />hydrocarbons (undecane and dodecane) are more likely to volatilize from open sail microcosm
<br />than the heavier ones (ttidecane and tetradecane). In an open soil microcosm, higher molecular
<br />weight organics are more likely to biodegrade than the lighter ones.
<br />Based on the findings from microcosm studies, biodegradation of hydrocazbons is likely to
<br />occur in soil where there is less opportunity to volatilize. [n a one liter headspace at standard
<br />conditions, hydrocarbons are not expected to volatilize significantly and thus, any disappearance
<br />of hydrocarbons may be due to biodegradation and/or any other source of degradation. TPH
<br />cazbon is biodegraded to form cazbon dioxide and soil organic matter (which includes microbial
<br />biomass). A decrease in the concentration of hydrocarbons may lead to lower rates of
<br />mineralization and production of carbon dioxide. Endogeneous metabolism in which microbes
<br />feed on the existing organic matter in soil also produces carbon dioxide.
<br />Equilibrium values of the of major components of TPH in the formulations investigated are
<br />found to be below REL (Recommended Exposure Limit), which implies that these components
<br />do not pose a hazard for the indoor environment even if the equilibrium concentration is reached.
<br />The COz evolution curves obtained provide support for the biodegradation of TPH in ATM.
<br />References
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<br />Morris Plains, NJ, USA (2000).
<br />3. Anonymous, "Acrylamide," Environmental Health Criteria 49, World Health
<br />Organization, Geneva, Switzerland, 24, (1985),
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<br />Biotechnology: Reducing Risks from Environmental Chemicals Through Biotechnology,
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