1. F. Heralld ct {II. : New Tools for Diagnosing Underground Pollution
they are lighter than water,
they are poorly biodegradable in natural soil conditions,
gasoline is highly inflammable, and its vapors explosive,
45
some components can be dangerous at low concentrations in water, but
their threshold of taste and smell detection is very low. That is more
especially the case of aromatics which are also more soluble in water
than the other components.
2.2 Organo-halogen aliphatic compounds
These products are most commonly used as solvents in the chemical and
mechanical industries. Some of them have chlorines (the most frequent), and/or
bromines, and/or other components added to their molecular chains. They are:
heavier than water,
more fluid than water,
relatively soluble in water, and volatile,
strongly resistant to biodegradation in natural soil conditions,
considered dangerous in water at low concentrations (10 ppb), as they
have carcinogenic effects.
The most prevalent of these substances are: trichloroethylene (TeE) 1.1.1.,
trichloroethane (TeA), tetra chloroethylene (peE), chloroform, and bromoform.
2.3 Other hydrocarbons
These include a great number of products with very different properties and
behavior such as:
crude oil and heavy fuel, with a high viscosity and a large range of
components,
aromatic solvents, largely used in the paint industry, volatile,
inflammable, and relatively soluble in water,
aviation products (kerosene) intermediate between gasoline and gas-oil,
residues from coal mining and petroleum industry, encountered for
example on old gas production plants, and sometimes used as filling
material on old sites. These products (bitumins, tars and creosotes), are
complex mixtures of heavy hydrocarbons, more particularly polyaromatics, and sometimes phenols, which can present a real threat.
3 SOURCES OF SUBSURFACE INFILTRATION
The study of cases of infiltration of pollutants into the subsurface conclude that
some of them are accidental (motorway and rail accidents, rupture of pipelines,
etc.). More often, the source of contamination comes from leakages of pipes or
tanks and this from service-stations to refineries in petrol treatment and frequently
in plants where these products are used. Moreover, the stocking of products on
sites unadapted for this activity (unclassified landfill sites, and unauthorized
tipping/dumping), can be the source of very large-scale contaminations.
they are lighter than water,
they are poorly biodegradable in natural soil conditions,
gasoline is highly inflammable, and its vapors explosive,
45
some components can be dangerous at low concentrations in water, but
their threshold of taste and smell detection is very low. That is more
especially the case of aromatics which are also more soluble in water
than the other components.
2.2 Organo-halogen aliphatic compounds
These products are most commonly used as solvents in the chemical and
mechanical industries. Some of them have chlorines (the most frequent), and/or
bromines, and/or other components added to their molecular chains. They are:
heavier than water,
more fluid than water,
relatively soluble in water, and volatile,
strongly resistant to biodegradation in natural soil conditions,
considered dangerous in water at low concentrations (10 ppb), as they
have carcinogenic effects.
The most prevalent of these substances are: trichloroethylene (TeE) 1.1.1.,
trichloroethane (TeA), tetra chloroethylene (peE), chloroform, and bromoform.
2.3 Other hydrocarbons
These include a great number of products with very different properties and
behavior such as:
crude oil and heavy fuel, with a high viscosity and a large range of
components,
aromatic solvents, largely used in the paint industry, volatile,
inflammable, and relatively soluble in water,
aviation products (kerosene) intermediate between gasoline and gas-oil,
residues from coal mining and petroleum industry, encountered for
example on old gas production plants, and sometimes used as filling
material on old sites. These products (bitumins, tars and creosotes), are
complex mixtures of heavy hydrocarbons, more particularly polyaromatics, and sometimes phenols, which can present a real threat.
3 SOURCES OF SUBSURFACE INFILTRATION
The study of cases of infiltration of pollutants into the subsurface conclude that
some of them are accidental (motorway and rail accidents, rupture of pipelines,
etc.). More often, the source of contamination comes from leakages of pipes or
tanks and this from service-stations to refineries in petrol treatment and frequently
in plants where these products are used. Moreover, the stocking of products on
sites unadapted for this activity (unclassified landfill sites, and unauthorized
tipping/dumping), can be the source of very large-scale contaminations.