Patent Abstract:
The disclosure describes a composition, process and apparatus for soil remediation on site using an encapsulating agent to separate contaminants from soil. The contaminated soil is saturated with the encapsulating agent, creating an immediate reaction causing the contaminants to dissociate from the soil in favor of association with the encapsulating agent. The encapsulating agent attracts and associates with the contaminants but do not dissolve them, resulting in a clearly-defined heterogeneous mixture with at least three phases, wherein said phases include contaminants at the top of the mixture, encapsulation agent at the middle and cleansed soil at the bottom of the mixture.

Full Description:
RELATED APPLICATIONS 
     Provisional application No. 61/772,268, filed on Mar. 4, 2013. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     N/A 
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     The present invention relates to a composition, method and apparatus for removing soil contaminants, and more particularly for the removal of soil contaminants by saturating the contaminated soil with a recyclable, non-toxic encapsulation agent that separates oil and other contaminants from the soil. 
     Discussion of the Background 
     Soil contamination has become a major problem because of the large amounts of man-made pollutants and chemicals that have been put into the environment. These contaminants affect the environment and endanger people&#39;s health. People&#39;s health can be damaged by various ways; for example, by touching the soil, or by breathing the air in the area where the soil is. In addition to the foregoing, the people&#39;s health may be endangered due to ground water contamination as a direct result of the soil contaminants. Federal and state laws have been enacted to mandate the clean-up of both intentional and unintentional contaminated sites. 
     The most common causes of soil contamination are oil, diesel, gasoline, petroleum-based products or other hydrocarbons exposed over a surface, including soil and sand, or a body of water due to oil spills and others. Major sources of these contaminants are refineries, gas stations, chemical plants and oil industries. 
     Currently, several apparatus and methods are used to clean-up contaminated soil. Alcohol, petroleum-based solvents or water are among the methods used to dissolve the contaminants from the soil and then return the cleansed soil to the original site. However, these processes have a number of disadvantages. For instance, the solvent used in those processes dissolves the contaminants from the soil resulting in a homogeneous mixture of solvent/contaminant. In these cases, it requires different or several post-treatment processes, such as distillation, to separate the solvent/contaminant mixture in order to re-use the solvent in the soil remediation process as well as to properly dispose the contaminant pursuant to federal and state law. These post-treatment processes are expensive and time consuming. 
     Furthermore, in most processes large amounts of solvent is needed to completely clean the soil thus making the process expensive and ineffective. Also some of the solvents used in the art are toxic thus requiring post-treatment of the soil before returning it to the original site. 
     Therefore, there is a need for a composition, method and apparatus for treatment contaminated soil on site which uses a non-toxic encapsulating agent that can effectively separate or remove contaminants from soil but also that can be amenable to an easy separation from the contaminant. In light of this, the contaminants may be disposed pursuant to federal and state law, and the non-toxic encapsulating agent may be recycled back in the remediation process. 
     Thus, in view of the above-mentioned deficiencies in the art, an object of the present invention is to provide an encapsulating agent to be used in soil remediation which is non-toxic, non-flammable and non-harmful to flora or fauna and containing no carcinogens. 
     It is another object of the present disclosure to provide a water-soluble and biodegradable encapsulating agent. 
     It is another object of this disclosure to provide a continuous, closed-loop system, which recycles the encapsulating agent in the soil remediation process. 
     It is another object of the present disclosure to provide a method and composition simple and cost-efficient for removing soil contaminants. 
     Further another object of the present disclosure is to provide an apparatus for using a recyclable encapsulating agent that separates efficiently contaminants from soil at the original contaminated site. 
     Furthermore, the encapsulation agent of the present disclosure is effective for acting as a cleaning solvent for petroleum products, such as oil spill cleanups or removal of tar and grease waste. 
     SUMMARY 
     In accordance with the principles of the present invention, a soil remediation composition, method and apparatus are provided. Soil remediation is preferably made at the original contaminated site with a portable remediation apparatus. Contaminated soil is excavated and cleansed in the remediation apparatus with a non-toxic, biodegradable encapsulating agent and then the cleansed soil is returned to the original site free from contaminants. Residues of the encapsulating agent in the cleansed soil are susceptible to biodegradation and would not harm the environment or the flora at the original site. 
     The encapsulating agent of the present disclosure comprises an anionic surfactant, an alcohol, a non-ionic surfactant, pine oil and water. In accordance with the principles of the present disclosure, the encapsulating agent is mixed with the contaminated soil with a sufficient amount to saturate the contaminated soil. The encapsulating agent creates an immediate reaction causing the contaminants to dissociate from the soil in favor of association with the encapsulating agent. The admixture of contaminated soil and encapsulating agent is agitated for a period of time sufficient to permit complete contact between the encapsulating agent and the contaminated soil to promote full disassociation of the contaminants from the soil in favor of association with the encapsulating agent. The encapsulating agent attracts and associates with the contaminants but does not dissolve them, resulting in a clearly-defined heterogeneous mixture with at least three phases, wherein said phases include contaminants at the top of the mixture, encapsulation agent at the middle of the mixture and cleansed soil at the bottom of the mixture. 
     The cleansed soil is free from contaminant or contains residues of contaminants at levels permitted by federal and state law and thus can be returned to the original site. The contaminants such as oil, diesel, gasoline or other hydrocarbons are easily separated from the heterogeneous mixture comprising encapsulating agent/contaminants by a skimming process. The encapsulating agent is then recycled back into the soil remediation process of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein, constitute part of the specification and illustrate the preferred embodiment of the disclosure. 
         FIG. 1  shows a general structure of the present disclosure in accordance with the principles of the present disclosure. 
         FIG. 2  shows a more detailed embodiment of the method and apparatus for remediation of soil of the present disclosure in accordance with the principles of the present invention. 
         FIG. 3  shows an exemplary embodiment of the method and apparatus for remediation of soil between the shaker and the encapsulating agent tank in accordance with the principles of the present disclosure. 
         FIG. 4  shows an exemplary embodiment of the method and apparatus for the third chamber of the encapsulating agent tank in accordance with the principles of the present disclosure. 
         FIG. 5  shows a flow chart of the exemplary process for treating contaminated soil in accordance with the principles of the present disclosure. 
         FIG. 6  shows the effectiveness of the encapsulating agent when saline water (water with salt) is used. Due to the fact that the encapsulating agent may use sea water as the water component, it lowers the costs in obtaining or using deionized water. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The encapsulating agent of the present disclosure comprises an anionic surfactant, an alcohol, a non-ionic surfactant, pine oil and water. 
     Anionic Surfactant 
     Anionic surfactants suitable to be used in the present invention include: sodium lauryl sulfate, alkali metal salts, ammonium salts, alkyl sulfates, alkyl ether sulfates, and generally the alkyl or acyl radical in these various compounds comprise a carbon chain containing 12 to 20 carbon atoms. In the preferred embodiment the anionic surfactant is sodium lauryl sulfate, preferably the composition commercially available under the tradename Lessrex 70®. 
     The anionic surfactant may be present in the compositions in amounts of up to about 6% by weight, but most preferably in amount of between from 0.8% to 3%. 
     Alcohol 
     Exemplary alcohols to be used in the present invention to enhance the miscibility of the pine oil in water include: lower alkyl alcohols, especially C 1 -C 8  alcohols, preferably isopropyl alcohol, propanol and ethanol. In the preferred embodiment the alcohol is isopropyl alcohol. 
     The alcohol may be present in the compositions in amounts of up to about 6% by weight, but most preferably in amount of between from 0.8% to 3%. 
     Nonionic Surfactants 
     Nonionic surfactants suitable for the present invention include condensation products of one or more alkylene oxide groups with an organic hydrophobic compound, such as an aliphatic or alkyl aromatic compound. Suitable nonionic surfactants include alkoxylated alcohols which include ethoxylated alcohols. 
     Exemplary alkoxylated alcohols include certain ethoxylated alcohol compositions commercially available include Neodol® from Sheel Company, which is described as a linear alcohol ethoxylate, Tergitol® from Union Carbide Co. (Danbury, Conn.), which is described as a secondary alcohol ethoxylate, and Imbirex CR® from American Chemical, which is described primary as an alcohol ethoxylated. In the preferred embodiment the nonionic surfactant is an ethoxylated alcohol, preferably the composition commercially available under the tradename Imbirex CR®. 
     The nonionic surfactant may be present in the compositions in amounts of up to about 3% by weight, but most preferably in amount of between from 0.4% to 1.5%. 
     Pine Oil 
     Pine oil is a complex blend of oils, alcohols, acids, esters, aldehydes, and other organic compounds. These include terpenes which include a larger number of related alcohols or ketones. Preferred terpenes are mono- and bicyclic monoterpenes, especially those of the hydrocarbon class, which can be selected from terpinenes, terpinolenes, limonenes and pinenes. Highly preferred materials of this type include d-limonene, dipentene, α-pinene, β-pinene and the mixture of terpene hydrocarbons obtained from the essence of oranges. 
     Particularly effective pine oils which are presently commercially available include Unipine 60 (from Union Camp, which is believed to contain approximately 60% terpene alcohols), Unipine® S-70 and Unipine® S-70 (from Union Camp, both are believed to contain approximately 70% terpene alcohols), and any other pine oil up to 100% terpene alcohol. Other examples of commercially available pine oils can be found in U.S. Pat. No. 5,728,672. 
     The pine oil may be present in the compositions in amounts of up to about 6% by weight, but most preferably in amount of between from 0.8% to 3%. 
     Water 
     Deionized water, tap water or sea water may be used in the present invention. Surprisingly, using sea water (water with concentration of salts of about 1%-5%) provides with a better encapsulating agent for removing soil contaminants. Because sea water may be used in the present invention, it lowers the cost in obtaining or using deionized water. 
     Water may be present in the compositions in amounts of up to about 97% by weight, but most preferably in amount of between from 90% to 95%. 
     In one embodiment of this disclosure, the anionic surfactant is mixed with the alcohol in equal parts and stirred until a homogeneous phase is achieved and it shows luminous halos. The resulted mixture is blended with the non-ionic surfactant and stirred until a homogeneous phase is achieved. The resulted mixture is further blended with the pine oil and stirred until a homogeneous phase is achieved. The resulted mixture is further blended with water and stirred until a homogeneous phase is achieved. Then, the mixture is allowed to rest. The resulting mixture is the encapsulating agent  30 . 
     In accordance with the principles of the present invention, a soil remediation process is performed on-site of the contaminated area, allowing in the case of contaminated sand to be cleansed and returned to the beach restoring the site. Therefore, the apparatus is preferably portable. 
     The term soil includes: soil, sand, and other solid surfaces such as petroleum tanks. Also it includes water, and other liquid surfaces which have been contaminated with contaminants. The term contaminants include, but is not limited to, oil, gasoline, diesel, petroleum-based products and other hydrocarbons. 
     Referring now to the drawings,  FIGS. 1-5  shows a soil remediation process and apparatus embodying the principles of the present invention, which is designated generally by the reference number  100 . 
     The soil remediation process starts with the collection of the contaminated soil on site. A loader or bobcat is used to excavate from the ground the contaminated soil and is delivered to the portable, soil remediation apparatus  100  via a hopper  5 . In one embodiment of the present disclosure, the hopper  5  contains at its entrance a size-limiting screen  21 . Contaminants may act as binders that can agglutinate the soil with other materials such as stones, rocks, the same soil, and other materials. In this instance, the particle size of the soil will be larger than the median particle size of the soil at that site. Agglomeration, also, may prevent the encapsulating agent  30  to fully remove the contaminants from soil. 
     In light of the foregoing, it is preferred that a study of the characteristics of the soil is performed to determine the median particle size of the soil. The size of the limiting screen  21  will be equal or similar to the median particle size. In this case, the size-limiting screen  21  will prevent the passage of large, agglutinated particles to the soil remediation process  100 . Instead, those agglutinated particles are deposited into a grinder, as shown in  FIG. 1 , that mechanically breaks the agglutinated soil into a particle size equal or similar to the median particle size. The purpose of this is to avoid any damages or changes in the characteristics of the soil in the remediation process, allowing the site to retain its characteristics when the soil is returned. Also breaking the agglutinated soil into smaller particles increases the surface area that will be in contact with the encapsulating agent  30 , thus facilitating the removing of contaminants. 
     The contaminated soil is transported from the hopper  5  by means of a conveyer belt or any other transporting means and deposited into a mixer M. 
     An encapsulating agent tank  50 , as shown in  FIG. 2 , contains at least three chambers: a first chamber  50   a , a second chamber  50   b  and a third chamber  50   c . The encapsulating agent tank  50  is partially filled with the encapsulating agent  30  before any contaminated soil is introduced into the soil remediating apparatus  100 . 
     The encapsulating agent  30  is transferred from the first chamber  50   a  of the encapsulating agent tank  50  to the mixer M with a pump P 10 , as shown in  FIG. 2 . The contaminated soil is stirred, mixed and blended with the encapsulating agent  30  in the mixer M by means of blades, mixers, stirrers, electric motor or any other agitation unit capable of mixing the contaminated soil with the encapsulating agent  30 . 
     The contaminated soil is saturated with the encapsulating agent  30  in the mixer M. Preferably the ratio of encapsulating agent  30  to contaminated soil is at least 3:1. Once the contaminated soil is saturated with the encapsulating agent  30  for a period of time sufficient to allow complete interaction between them, the encapsulating agent  30  creates an immediate reaction causing the contaminants  31  to dissociate from the soil in favor of association with the encapsulating agent  30 . The admixture  3  comprising contaminated soil and encapsulating agent  30  is transported upward from the mixer M to at least one soil shaker  12  by means of an impeller pump P 1  or any other transporting means, capable of moving both the solid (soil) and the liquids (contaminants  31  and encapsulating agent  30 ), as shown in  FIG. 1 . At this point, the encapsulating agent has attracted most of the contaminants  31 , resulting in a heterogeneous mixture of mainly two phases. The first phase is substantially a solid phase comprising cleansed soil, which contains larger particles, and the second phase is substantially a liquid phase comprising the contaminants  31  and the encapsulating agent  30 , which contain smaller particles. 
     As shown in  FIG. 3 , the shaker  12  comprises a screen  23  having a particular mesh size. Usually shaker  12  is shaken with reciprocating linear movement along a horizontal axis. The movement is designed to cause material resting on the screen  23  to slide forward slightly with each cycle of motion, and perhaps falling through one of the holes  121  if the particle is small enough. Due to the fact that the cleansed soil contains large particles, said cleansed soil does not fall through the screen  23 , and the cleansed soil is eventually ejected off of the forward end of the screen  23  into a recovery soil tank  15  for immediate return to the site. 
     The cleansed soil may contain traces of contaminants  31  but are at levels permitted by federal and state environmental regulations. Furthermore, the cleansed soil may contain traces of the encapsulating agent  30 . However, the cleansed soil may be returned to the original site safely since the encapsulating agent  30  is non-toxic and biodegradable. 
     Soil shaker  12  is preferably positioned directly over the third chamber  50   c  of the encapsulating agent tank  50 , as shown in  FIG. 3 . The liquid phase passes through the shaker screen  23  and falls into the third chamber  12   c . Also small particles of soil  8  pass through the shaker screen  23  and falls into the third chamber  50   c.    
     In the third chamber  50   c  of the encapsulating agent tank  50 , the process for the separation of the components of the liquid phase starts.  FIG. 3  explains the separation process more in details. Mainly the liquid phase is allowed to rest inside the third chamber  50   c . Due to their differences in densities each component of the liquid phase starts to separate from each other providing two layers. The contaminants  31 , being less dense than the encapsulating agent  30 , will tend to float to the top of the liquid phase. The encapsulating agent  30  will tend to rest at the bottom of the liquid phase. The smaller particles of soil  8  will tend to settle at the bottom of the third chamber  50   c.    
     The contaminants  31  at the top of the liquid phase are removed with a pump P 3  into a contaminant recovery tank  40 . The pump P 3  is preferably positioned at a predetermined height H 3  of a first wall W 1  of the third chamber  50   c , as shown in  FIG. 4 . The height H 3  is adjusted in conjunction with the flow rate of the contaminated soil entering the apparatus  100  and the pump P 10  to cause a predetermined depth of fluid to be continuously removed from the top of the liquid phase of the third chamber  50   c  into the recovery contaminant tank  40 . 
     The recovered contaminant  31  in the recovery contaminant tank  40  is essentially free from the encapsulating agent  30  and the smaller soil particles  8 . In the case that the contaminant  31  is oil, the recovered oil may be used as heating oil or any other oil fuel application. 
     The third chamber  50   c  also contains a second wall W 2 , which is opposite to the first wall W 1 , as shown in  FIG. 3 . The encapsulating agent  30  in chamber  50   c  flows to the second chamber  50   b  by means of an inlet IN located at the bottom of the second wall W 2 . The inlet IN is positioned at a predetermined depth of the second wall W 2  in order to prevent that any contaminant  31  that is floating at the top of the liquid phase in chamber  50 C passes to chamber  50   b . The liquid phase that flows from chamber  50   c  to the second chamber  50   b  comprises only the encapsulating agent  30  and some smaller particles of soil  8 , which will tend to settle at the bottom of the second chamber  50   b.    
     The second chamber  50   b  contains a first skimming wall W 3 , which is opposite to the second wall W 2 , as shown in  FIG. 3 . The encapsulating agent  30  in the chamber  50   b  flows over the first skimming wall W 3  to the first chamber  50   a . Most of the smaller soil particles  8  are retained at the bottom of chamber  50   b . Only a minimum amount of smaller particles of soil  8  passes with the encapsulating agent  30  by overflow to chamber  50   a.    
     Small particles of soil  8  in chambers  50   a ,  50   b  and  50   c  have a particle size smaller than 35-40 microns. Particles of this size become very difficult to separate with soil shakers. In order to remove the smaller soil particles  8  from the encapsulating agent  30  in each of the chambers  50   a ,  50   b  and  50   c , it is preferred to pass the fluid containing said small particles of soil  8  through a desilter unit  25 , which are known in the industry as “hydrocyclones”, as shown in  FIG. 2  and  FIG. 4 . 
     The desilter unit  25  is preferably positioned directly over the second chamber  50   b , as shown  FIG. 2 . The desilter unit  25  separates the small particles of soil  8  from the encapsulating agent  30 . Each chamber  50   a ,  50   b , and  50   c  contains a pump P 30  at its bottom that transfers the fluid containing encapsulating agent  30  and small particles of soil  8  to the desilter unit  25 , as shown in  FIG. 3 . 
     The small particles of soil  8  recovered from the desilter unit  25  are forward to the recovery soil tank  15 . The encapsulating agent  30 , which is not retained in the desilter unit  25 , falls into the second chamber  50   b  essentially free from smaller soil particles  8 . 
     Through the actions of the separation process through difference in densities of the encapsulating agent  30  and the contaminants  31  in chamber  50   c , in combination to the progressive skimming in the encapsulating agent tank  50 , with the soil shaker  18  and the desilter unit  25 , the encapsulating agent  30  of the first chamber  50   a  is substantially free from contaminants  31  and smaller soil particles  8  and, therefore, is available to be recycled back to the remediation process of the present disclosure. 
     The recirculation of the encapsulating agent  30  in the closed-loop remediation process, over time, will cause the concentration of the encapsulating agent  30  to decrease. In this case, new amounts of encapsulating agent  30  must be introduced into the system. The monitoring of the concentration of the encapsulating agent  30  may be done by manual sampling, visual inspection or with an optical detection system (not shown) that automatically monitors the light transmissivity of the encapsulating agent  30 , as is known. 
     EXAMPLES 
     Table 1. shows the results of several tests performed to evaluate the effectiveness of the encapsulating agent in removing oil and other contaminants from sand. Different amounts of oil and other contaminants were added to a sand sample in the several tests. The encapsulating agent comprises: 1.43% of Lessrex 70®(sodium lauryl sulfate), 1.43% of isopropyl alcohol, 0.71% of Imbirex Cr®(ethoxylated alcohol), 1.43% of pine oil and 95% of water. After saturating the contaminated sand with the encapsulating agent, as can be observed from the results in Table 1, in all trials the TPH in the samples were low with over 90% of oil recovery. 
     
       
         
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
               
               
                 Concentration 5% Active Ingredient of Encapsulating Agent 
               
             
          
           
               
                 Initial 
                   
                   
                   
                   
                   
               
               
                 percentage 
                 Oil 
                 Percentage 
                 TPH or Total 
                 Recovered 
                 Percent- 
               
               
                 of oil in 
                 Volume 
                 of Oil 
                 Petroleum 
                 Volume 
                 age of 
               
               
                 samples 
                 (ML) 
                 and grease 
                 Hydrcarbon 
                 (MI) 
                 Recovery 
               
               
                   
               
             
          
           
               
                  5% 
                 6.5 
                 .30% 
                 0.14 
                 6.1 
                 93.84% 
               
               
                 10% 
                 12.5 
                 .34% 
                 0.16 
                 12.1 
                 96.80% 
               
               
                 15% 
                 19.5 
                 .68% 
                 0.32 
                 18.6 
                 95.38% 
               
               
                 20% 
                 27.5 
                 .72% 
                 0.36 
                 26.5 
                 96.36%

Technology Classification (CPC): 1