Pollution remedial composition and its preparation

Pollution remedial compositions are disclosed which comprise a soluble silicate, a surfactant, a polyol, and water.

BACKGROUND OF THE INVENTION 
This invention relates to a pollution remedial composition, its 
manufacture, and method of using the pollution remedial composition. 
Hazardous Wastes, toxic spills, contaminated water, contaminated soil, and 
pollutants are but a few of the environmental problems we face today all 
over the world. Since late 1970's, great concern was expressed over the 
disposal of hazardous or toxic wastes. 
Common pollutants in soil and in water include asbestos, polychlorinated 
biphenyls ("PCB"), chlorinated hydrocarbons, petroleum products, 
pesticides, herbicides, and heavy metals. Most of these pollutants are 
man-made and have relatively long half-lives. Recent development and 
dissemination of such sophisticated and sensitive equipment as gas 
chromatographs, coupled with flame ionization and electron capture 
detectors, have allowed detection of pollutants with unheard of precision 
and accuracy. 
Asbestos was used extensively prior to the 1980's to insulate structural 
steel and heating ducts, as a fibrous material in acoustical ceilings, in 
various applications on space heating and cooling units, in roofing 
papers, and in vinyl tiles adhesives. Asbestos can be analyzed and 
identified rapidly and inexpensively by microscopic analysis. Removal of 
the asbestos from a contaminated site is possible, but the task is 
invariably expensive. Further, it is never the best solution if the job is 
not properly done. 
PGB's are widely used as insulation in electrical equipment, such as 
transformers and capacitors. If an electrical equipment contains PCB's, 
the equipment, its support platform, and the soil under and around the 
area most likely will contain these pollutants. The polymers are, to a 
certain extent, fire resistant. When they are burned, however, some toxic 
dioxin is formed as a by-product of the combustion, along with phosgene 
and hydrochloric acid. The toxic dioxin produced is the toxin reported in 
"Agent Orange." PCB's biodegrade very slowly. Their very low vapor 
pressure precludes their loss to the atmosphere. Thus, cleanup of PCB's is 
particularly expensive since incineration is the normal method of 
decontamination of removed material. 
Chlorinated hydrocarbons have been widely used for at least five decades. 
These materials are used in paint thinners, paint strippers, degreasers, 
and "dry cleaning" solvents. Chlorinated hydrocarbons generally include 
dichloromethane, chloroform, carbon tetrachloride, dichloroethenes, and 
others. Carbon tetrachloride is very toxic and when burned forms phosgene 
and hydrochloric acid. Chlorinated hydrocarbons have relatively high vapor 
pressure, and their density is greater than that of water. These solvents 
are very likely to enter soil and groundwater. These materials enter the 
soil rapidly and move downward as liquid. Decontamination soil containing 
this class of pollutants is usually done by excavation and gas extraction. 
At one time, the decontamination was done by volatilization to atmosphere. 
Now, this old method is not considered acceptable in most areas. 
Petroleum product pollutants are common in virtually every area used by 
man. Petroleum products include motor fuels, standard solvents, kerosene, 
and paint thinners. Benzene, a constituent of gasoline, is carcinogenic. 
The most prevalent risk today is from leaking tanks. There is usually very 
little opportunity for degradation deep in the soil column or in an 
underground water column. 
Pesticides and herbicides have been in general use since the early 1940's. 
They were used on farm crops, for right-of-way control, for forest 
management, and even for decorative management in houses and gardens. 
Pesticides are not only toxic but degrade slowly. Cleanup of these 
pollutants is exceedingly expensive. 
The most common heavy metal pollutants include lead, chromium, and mercury. 
Lead has been widely used in car batteries and paints. These heavy metals 
do not degrade because they are basic elements. Some, such as mercury, 
are, however, capable of biotransformation from inorganic to organic 
forms. One of the techniques to decontaminate such pollutants is 
adjustment of the pH. Oxidation and reduction actions are also used to 
decontaminate these pollutants. 
Although not considered a pollutant, forest fires, oil-field fires and 
other fires are likewise hazardous. They are hazardous not only because of 
the damage they cause to the properties and materials, but also because of 
the gases generated by them. 
For large scale decontamination of soil pollutants, one of the ways 
currently used is to excavate the soil, spread the soil out on a 
polyethylene film sheet, then allow the low-boiling hydrocarbons to be 
released into the air. Afterward, the soil must be taken to a hazardous 
waste landfill or even transported to an incinerator where the remaining 
pollutants are burnt. In burning this soil, gases, some toxic, are 
released to the air. Even after this costly procedure, the remainder still 
may have to be deposited into a hazardous waste landfill. 
Biological treatment of wastes has also been tried. In this method, the 
pollutants are exposed to some microorganisms. The method will fail, 
however, if the annual rainfall is high and the erosion potential is not 
minimal. Difficulties also arise when the technique is applied in a 
careless manner. 
It is thus clear that there is an urgent need for an effective pollution 
remedial composition. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide a new and 
effective pollution remedial composition, method of its manufacture, and 
method of using the composition. 
It is another object of the present invention to provide a pollution 
remedial composition that can effectively decontaminate an area of ground, 
or a volume of water, containing various pollutants. 
It is yet another object of the present invention to provide a pollution 
remedial composition that can eliminate the high cost of removal and 
excavating contaminated soil and water. 
It is also an object of the present invention to provide a pollution 
remedial composition that can be used, under certain conditions, to 
reclaim a heavy metal from a sludge. 
It is another object of the present invention to provide a pollution 
remedial composition that can effectively extinguish fires. 
It is still another object of the present invention to provide a pollution 
remedial composition that can de-grease oils from an area, either an area 
from a mammalian skin or an area on a driveway. 
It is also an object of the present invention to provide a pollution 
remedial composition containing: From about 40 to about 75 volume % of a 
soluble silicate; from about 0.25 to about 5 volume % of a surfactant; 
from about 1 to about 5 volume % of a polyol; and the remainder water. 
It is a further object of the present invention to provide a method for 
preparing a pollution remedial composition containing the steps of: Adding 
with agitation, from about 0.25 to about 1 volume % of an anionic 
surfactant to water, ranging from about 35 to about 45 volume %, to obtain 
a first substantially homogeneous resultant mixture; adding, with 
agitation, from about 1 to about 2 volume % of an ethylene glycol to the 
first resultant mixture to obtain a second substantially homogeneous 
resultant mixture; adding, with agitation, from about 0.2 to about 1 
weight percent of a combination of equal amount of citric acid and sodium 
chloride to the second resultant mixture to obtain a third substantially 
homogeneous resultant mixture; and adding, with agitation, from about 55 
to about 60 volume % of sodium silicate to the third resultant mixture to 
give a substantially homogeneous said remedial composition. 
It is still another object of the present invention to provide a method for 
remedying an area of ground polluted with contaminants containing the 
steps of: Administering evenly to a polluted area a sufficient amount of a 
pollution remedial composition to decontaminate the area; simultaneously 
tilling the area until the pollution remedial composition is substantially 
well dispersed in the area; and allowing the area to dry.

DETAILED DISCUSSION 
Broadly, the pollution remedial composition of the present invention 
contains from about 40 to about 75 volume % of a soluble silicate; from 
about 0.25 to about 5 volume % of a surfactant; from about 1 to about 5 
volume % of a polyol; and the remainder water. 
Optional ingredients for the present invention include sodium chloride, 
citric acid, and glycerine. 
Soluble silicates are systems containing varying proportions of silica and 
an alkali metal or quaternary ammonium ion. The most common and most 
widely used soluble silicates are those of sodium and potassium. 
Ordinarily, soluble silicates can be produced over a wide range of 
stoichiometric and non-stoichiometric composition and are distinguished by 
the ratio of silica to alkali metal. The ratio is generally expressed as 
the weight percent ratio of silica to alkali-metal oxide. 
Sodium silicates have wide application in many types of detergents and 
cleaning compounds. They have also been used for many years as adhesives 
and cements. Thus, they find wide application for pelletizing, 
granulating, and briqueting finely divided particles, such as clays, 
fertilizers, and ores. Sodium silicates also are used as bonding.sub.s 
materials for foundry mold and core compositions. They have also been used 
as coatings, to protect against water-line corrosion in tanks. Soluble 
alkali-metal silicate solutions are not compatible with most organic 
water-miscible solvents. The addition of organic solvents, such as 
alcohols and ketones, causes phase separation into separate liquid layers. 
Nevertheless, a few organic systems, such as polyols, are compatible and 
miscible with alkali-metal silicate solutions. Examples of polyols include 
glycols, glycerins, sugars, and polyethylene glycols. 
For the present invention, the most preferred soluble silicate is sodium 
silicate. Usable commercial sodium silicates include Sodium Silicate 
Liquid Grade 42 from Occidental Chemical Corp., Niagara Falls, N.Y., and 
Power Silicate, Crofton, Md. Soluble sodium silicate in this invention is 
present at a level from about 40 to about 75%, based on the total volume 
of the final pollution remedial composition. Preferably, the ingredient 
should be present at a level from about 55 to about 60 volume %. Most 
preferably, about 57.5 volume % of the soluble sodium silicate should be 
used. 
The next ingredient used for the pollution remedial composition of the 
present invention is a surfactant. 
A surfactant is an organic compound consisting of two parts: (1) A 
hydrophobic portion, usually including a long hydrocarbon chain; and (2) a 
hydrophilic portion which renders the compound sufficiently soluble in 
water or other polar solvents. The combination of hydrophobic and 
hydrophilic portions in a surfactant render the surfactant surface-active 
and thus able to concentrate at the interface between a surfactant 
solution and another phase such as soil or other substrate to be cleansed. 
Surfactants are usually classified into: (1) Anionic, where the hydrophilic 
portion of the molecule carries a negative charge; (2) cationics, where 
the hydrophilic portion of the molecule carries a positive charge; and (3) 
nonionics, which do not dissociate, but generally derive their hydrophilic 
portions from polyhydroxy or polyethoxy structures. Other surfactants, 
though less common, are ampholytic and zwitterionic surfactants. The most 
commonly used surfactants are the anionic surfactants. Generally, they are 
linear sodium alkyl benzene sulfonate, linear alkyl sulfates, linear alkyl 
ethoxy sulfates, and organo-phosphoric acid esters. 
For this invention, the preferred surfactants are the anionic surfactants. 
Further, the most preferred anionic surfactants are esters of 
organo-phosphoric acid. Commercially, organo-phosphoric acid ester is sold 
under the tradename "T MULZ," No. 598 480, available from Harcros 
Chemicals Inc., Kansas City, Kans. This commercial product has a boiling 
point of 290.degree. F. @ 760 mm Hg. The specific gravity (H(2)0=1) is 
1.111 @77.degree. F. The pH of a 1% aqueous solution of this product is in 
the range of 2 to 3. It is a clear amber liquid. 
The surfactant in this invention is present at a level from about 0.25 to 
about 5%, based on the total volume of the final pollution remedial 
composition. Preferably, this ingredient should be present at a level from 
about 0.25 to about 1 volume %. Most preferably, about 0.5 volume % of the 
anionic surfactant, the organo-phosphoric acid ester ("T Mulz" No. 598 
480) should be used. 
The next ingredient used for the present invention is a polyol. Known 
polyols include different glycols, glycerins, sugars, and polyethylene 
glycols. These polyols are compatible and miscible with alkali-metal 
silicate solutions. 
The preferred polyol for this invention is ethylene glycol. Ethylene glycol 
has a molecular weight of 62; a boiling point of 197.6.degree. C. (760 mm 
Hg); a specific gravity of 1.1155 (20.degree. C./20.degree. C.); and a 
freezing point in air of -13.degree. C. (760 mm Hg). It is completely 
soluble in water. Ethylene glycol is traditionally associated with its use 
as an antifreeze for internal-combustion engine cooling systems. The 
compound has also been used in the production of polyesters for fibers, 
films, and coating. Commercially, ethylene glycol can be purchased from 
Dow Chemical U.S.A., Midland, Mich. 
Polyol in this invention is present at a level from about 1 to about 5%, 
based on the total volume of the final pollution remedial composition. 
Preferably, polyol should be present at a level from about 1 to about 2 
volume %. Most preferably, about 1.5 volume % of the ethylene glycol 
should be used. 
Water forms the remainder of the pollution remedial composition of the 
present invention. It can be present from about 10 to about 58%, based on 
the total volume of the final pollution remedial composition. Preferably, 
it should be present from about 35 to about 45 volume %. Most preferably, 
it should be present in an amount of about 40 volume %. 
Sodium chloride is an optional ingredient that can be included in the 
pollution remedial composition of the present invention. Sodium chloride 
is present at a level ranging from about 0.1 to about 5%, based on the 
total weight of the final pollution remedial composition. Preferably, the 
weight percent of sodium chloride should be from about 0.1 to about 0.5. 
Most preferably, sodium chloride should be present in about 0.25 weight %. 
Another optional ingredient that can be used in the pollution remedial 
composition of the present invention is citric acid. Citric acid is 
soluble in water or alcohol. The compound is a tribasic acid, forming 
mono-, di-, and tri-series of salts and esters. It is a white crystalline 
solid, having a melting point of 153.degree. C. Citric acid is present at 
a level ranging from about 0.1 to about 5%, based on the total weight of 
the final pollution remedial composition. Preferably, the weight percent 
of citric should be from about 0.1 to about 0.5. Most preferably, citric 
acid should be present in about 0.25 weight %. The weight percent of 
citric acid is normally maintained at a level equal to that of sodium 
chloride in the pollution remedial composition of the present invention. 
Another optional ingredient for the pollution remedial composition of the 
present invention is glycerins. In fact, glycerins can be used to replace 
the combination of sodium chloride and citric acid. For the present 
invention, about 1 to about 5%, based on the total volume of the final 
pollution remedial composition, of glycerine can be used. Preferably, the 
volume percent of glycerins should be from about 1 to about 2%. Most 
preferably, glycerins should be present in about 1.5 volume %. 
METHOD OF MANUFACTURE 
The pollution remedial composition of the present invention was made by 
adding with agitation, about 0.5%, based on the total volume of the final 
remedial composition, of an organo phosphoric acid ester anionic 
surfactant, T MULZ 598 480, to water present in an amount of about 40 
volume % to obtain a first substantially homogeneous resultant mixture. 
Then, with agitation, about 1.5 volume % of ethylene glycol was added to 
the first resultant mixture to obtain a second substantially homogeneous 
resultant mixture. Subsequently, still with agitation, about 0.5%, based 
on the total weight of the final remedial composition, of a combination of 
equal amount of citric acid and sodium chloride was added to the second 
resultant mixture to obtain a third substantially homogeneous resultant 
mixture. Finally, about 57.5 volume % of sodium silicate was added, 
accompanied by agitation, to the third resultant mixture to give a 
substantially homogeneous said remedial composition. 
COMPOSITION 
The following composition is representative of the present invention. 
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Component % 
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Sodium Silicate 57.5 (by volume) 
Ethylene Glycol 1.5 (by volume) 
T MULZ 590 480 0.5 (by volume) 
Sodium Chloride 0.25 (by weight) 
Citric Acid 0.25 (by weight) 
Water 40 (by volume) 
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This pollution remedial composition is stable and effectively 
decontaminates pollutants from a soil sample or from water having 
pollutants floating thereon. The pollution remedial composition can also 
be used to de-grease a driveway or a human body surface. Further, the 
pollution remedial composition is effective in putting out fire. Moreover, 
the pollution remedial composition can be used, in a closed system, to 
recover mercury from a sludge. 
INDUSTRIAL APPLICABILITY 
EXAMPLE 1 
To a liquid contaminant, such as an insecticide, a petroleum product, or a 
chlorinated hydrocarbon, placed in a jar was added about 25 volume % of 
the pollution remedial composition of the present invention. The mixture 
was then agitated until the ingredients were well mixed. The mixture 
generally turned cloudy, and was sent to a commercial laboratory for 
quantitative analysis of the residual liquid contaminant. A control, 
without being treated with the pollution remedial composition of the 
present invention, was also analyzed similarly. Generally, after sitting 
for a period of from about two to three weeks, solid matrix formed and 
precipitated to the bottom of the jar. 
The test results obtained are shown in FIGS. 1-5. It can be seen from these 
figures that in each instance, the concentration of the liquid contaminant 
in the residue dramatically decreased after treatment with the pollution 
remedial composition of the present invention. 
FIG. 5 shows the test results obtained from treating each of benzene, 
toluene, ethylbenzene, a mixture of m-xylene and p-xylene, and o-xylene 
with the pollution remedial composition of the present invention,. In 
every case, the concentration of the treated chemical was significantly 
lower than that of the control. 
EXAMPLE II 
To clean a driveway stained with oil, grease, paint, etc., the pollution 
remedial composition of the present invention was applied to the stained 
area. After the application, either one of the two options was used: (1) 
The composition was allowed to stay in the driveway to dry, giving a clean 
driveway when dried; or (2) the composition was allowed to stand for 15 to 
30 minutes on the driveway which was then flushed with water to wash the 
stain off from the area. 
EXAMPLE III 
To clean greasy-oily hands, the pollution remedial composition of the 
present invention was applied to the hands. Hands were rubbed together to 
evenly coat areas of grease and oil. Hands were then washed under water to 
get rid of the grease, oil and the composition. 
EXAMPLE IV 
The effectiveness of a treatment method depends on the types of soil to be 
treated, the types of contaminants present in the soil, and the depth of 
contaminants present in the soil. 
Generally, the pollution remedial composition of the present invention can 
be used to remedy an area of ground polluted with contaminants as follows: 
Administering evenly to a polluted area of about 1 cubic yard 2 gallons of 
the pollution remedial composition to decontaminate the area. 
Simultaneously, the area is evenly tilled until the pollution remedial 
composition is substantially well dispersed in the area. Finally, the area 
should be allowed to dry. 
(A) If only a shallow layer of soil is contaminated, such as from about 
three inches to about one foot in depth of contamination, the tiller 
method should be used. In this method, the tiller with spray jets attached 
thereto would be used. At a slow speed, the tiller will till the soil and 
the spray jets would emit the pollution remedial composition to saturate 
the soil with the composition. After air drying, the contaminants will be 
encased in a glass-like matrix. 
(B) If a relatively deep layer of soil is contaminated, such as from about 
two to about four feet in depth of contamination, the method described 
above would still be used except it would take two stages. The first step 
would be as the treatment described above, and the next step would be to 
remove the first treated layer, lay it aside, and repeat the procedure on 
the next layer of soil. After this process has been done and the 
contaminant has been treated, the treated soil may then be returned to its 
original place. 
(C) Where the contaminant penetrates deep into the soil, then it is 
necessary to remove the layer of contaminated soil by using a front-end 
loader-type of machinery and putting the soil removed through a pug mill. 
As the soil is processed through the pug mill, the soil is thoroughly 
saturated with the pollution remedial composition of the present 
invention. When the process is finished, the soil will be ejected into a 
pile and, later, after all contaminates from the deepest region have been 
treated, the soil will be returned to the original location. 
(D) In areas where contaminated soil cannot be removed or in lieu of the 
pug mill method, then one or more perforated pipes may be injected into 
the ground, and the pollution remedial composition of the present 
invention can be slowly introduced into the perforated pipes to allow the 
composition to slowly penetrate the contaminated soil. This 
decontamination process is a slower process than the pug mill method or 
the tiller method because this process does not provide an aerated means, 
but the end results will be the same. 
EXAMPLE V 
Where contaminants are present in the water, then by adding to the water 
the pollution remedial composition of the present invention, the 
contaminants are segregated. The contaminants will be encased in a 
glass-like matrix and separated from the water. The glass-like matrix will 
sink to the bottom, leaving the water clean from contaminants. 
EXAMPLE VI 
Depending on the type of fire, either forest, oil, or grass, the 
composition of the present invention is to be sprayed on the fire at low 
pressure, or in instances of larger fires, the composition of the present 
invention may be applied from the air in a spray or dump motion. 
EXAMPLE VII 
The recovery of mercury from sludge can be accomplished by introducing the 
sludge through an agitation pug mill. The composition of the present 
invention is then applied to the sludge with agitation. The amount of the 
composition used is determined by the type of sludge to work on. The 
sludge would be put into the pug mill, and the composition of the present 
invention would be added and blended to evenly distribute the material 
therein. The pug mill needs to be slanted at an angle so that the 
recovered mercury can be collected at the bottom and be drained off. 
The invention now being fully described, it will be apparent to one of 
ordinary skill in the art that many changes and modifications can be made 
thereto without departing from the spirit or scope of the invention as 
defined in the following claims.