| US20040123881A1 | 2004-07-01 | |||
| GB902343A | 1962-08-01 | |||
| EP0699633A2 | 1996-03-06 | |||
| JPH08284147A | 1996-10-29 | |||
| EP0876846A2 | 1998-11-11 | |||
| US5244308A | 1993-09-14 | |||
| US20150000715A1 | 2015-01-01 | |||
| US20030175081A1 | 2003-09-18 |
| What is claimed is: 1. A method for soil remediation, the method comprising sequential steps of: placing soil debris in a container, the container defining a cylindrical cavity with a longitudinal axis and an inner surface; the container comprising a drain port in a bottom of the container and a screen with pores, the screen extending along the inner surface; adding a rinse solution comprising water into the cylindrical cavity such that the rinse solution contacts the soil debris, thereby forming a slurry; agitating the slurry by rotating the container about the longitudinal axis through at least a portion of a full rotation; draining liquids from the slurry through the pores in the screen and out the drain port, thereby removing a first portion of liquids from the slurry produce moist remediated soil; partially drying the moist remediated soil by rotating the container about the longitudinal axis to drain a second portion of liquids from the slurry, thereby producing partially dried remediated soil; and removing the partially dried remediated soil from the container. 2. The method as recited in claim 1 , further comprising pressing the partially dried remediated soil within the cylindrical cavity with a drum press that traverses along the longitudinal axis, the step of pressing occurring after the step of partially drying and prior to the step of removing. 3. The method as recited in claim 1, wherein step of removing removes the partially dried remedied soil from the container using an auger. 4. The method as recited in claim 1, wherein the rinse solution comprises the water and a chemical additive. 5. The method as recited in claim 4, wherein the chemical additive is selected from the group consisting of an amino acid, a hydrous manganese oxide (HMO), a humic acid, a citric acid, a porphin, a citrate, an ethylenediaminetetraacetic acid (EDTA), an ethylenediamine-N.iV-disuccinic acid (EDDS), and combinations thereof. 6. The method as recited in claim 1 , wherein the pores of the screen have a mesh size between three microns and ten-thousand microns. 7. The method as recited in claim 1 , wherein the step of removing transfers the remediated soil to a mixing unit. 8. The method as recited in claim 7, wherein the mixing unit comprises an open top, steel, leak proof tub. 9. The method as recited in claim 8, wherein the mixing unit further comprises a motorized screw, the method comprising mixing the remediated soil in the mixing unit using the motorized screw. 10. The method as recited in claim 7, the method further comprising a step of adding a solidifying agent to the mixing unit, the step of adding occurring after the step of removing, wherein the method is performed at a site such that the step of placing the soil debris in the container, the step of removing the partially dried remediated soil from the container and the step of mixing the remediated soil in the mixing unit are each performed at the site. 11. The method as recited in claim 10, further comprising returning the remediated soil to the site, the step of returning occurring after the step of mixing the remediated soil in the mixing unit. 12. The method as recited in claim 7, the method further comprising a step of adding a solidifying agent to the mixing unit, the step of adding occurring after the step of removing. 13. The method as recited in claim 1 , wherein the method is performed at a site such that the step of placing the soil debris in the container and the step of removing the partially dried remediated soil from the container are performed at the site. 14. A method for soil remediation, the method comprising sequential steps of: placing soil debris in a container through an intake port, the container defining a cylindrical cavity with a longitudinal axis and an inner surface; the container comprising a drain port in a bottom of the container, a hinged door at an end of the cylindrical cavity and a screen with pores, the screen extending along the inner surface; adding a rinse solution comprising water into the cylindrical cavity such that the rinse solution contacts the soil debris, thereby forming a slurry; agitating the slurry by rotating the container about the longitudinal axis; draining liquids from the slurry through the pores in the screen and out the drain port, thereby removing a first portion of liquids from the slurry, producing moist remediated soil; partially drying the moist remediated soil by rotating the container about the longitudinal axis to drain a second portion of liquids from the slurry, thereby producing partially dried remediated soil; pressing the partially dried remediated soil within the cylindrical cavity with a drum press that traverses along the longitudinal axis, thereby removing a third portion of liquids from the slurry; and removing the partially dried remediated soil from the container through the hinged door. 15. The method as recited in claim 14, wherein the step of agitating the slurry rotates the container a rotation rate of between five rotations per minute (RPM) and one- hundred RPM. 16. The method as recited in claim 15, wherein the rotation rate is maintained for a rotation duration of between three minutes and sixty minutes. 17. The method as recited in claim 16, wherein the step of removing transfers the remediated soil to a mixing unit. 18. The method as recited in claim 17, wherein the mixing unit further comprises a motorized screw, the method comprising mixing the remediated soil in the mixing unit using the motorized screw. 19. The method as recited in claim 18, the method further comprising a step of adding a solidifying agent to the mixing unit, the step of adding occurring after the step of removing, wherein the method is performed at a site such that the step of placing the soil debris in the container, the step of removing the partially dried remediated soil from the container and the step of mixing the remediated soil in the mixing unit are each performed at the site. 20. The method as recited in claim 19, further comprising returning the remediated soil to the site, the step of returning occurring after the step of mixing the remediated soil in the mixing unit. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and is a non-provisional of U.S. Patent
Application Serial 62/141,409 (filed April 1, 2015) the entirety of which is incorporated herein by reference.
BACKGROUND
[0002] Accidental contamination of soil debris (such as soils, tailing, muck, residual waste, sand, rock cuttings, and the like) occur in many industrial, environmental and natural settings. Many Government regulations impose a regulatory limit on the concentration of contaminates in the materials. Conventionally, the soil debris must be transported to a remote site where the soil is subjected to treatment. This significantly increases the costs of remediating the soil debris. An improved remediation method is therefore desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which:
[0004] FIG. 1 is a flow diagram for a method of soil remediation;
[0005] FIG. 2 is side view of a specialized container for use in a soil remediation
l method;
[0006] FIG. 3 is cross section side view of the specialized container for use in a soil remediation method;
[0007] FIG. 4 is front view of the specialized container for use in a soil remediation method;
[0008] FIG. 5 is a chart showing sizing parameters for various sieves;
[0009] FIG. 6 is a chart correlating U.S. mesh sizes to pore size;
[00010] FIG. 7 is a chart showing size ranges for various particles;
[00011] FIG. 8 is a side view of a truck that transports the specialized container and associated system;
[00012] FIG. 9 is a top view of the truck and a system for a soil remediation method; and
[00013] FIG. 10 is a side view of the specialized container utilizing gravity. DETAILED DESCRIPTION
[00014] The soil remediation method disclosed herein relates to a method for cleaning contaminated soil debris to acceptable regulatory governing limits at an onsite location (e.g. local disposal facility). The disclosed method is more cost effective than offsite disposal at a licensed facility. An advantage that may be realized in the practice of some of the disclosed embodiments is that the method reduces material contaminates to levels which are considered non-hazardous or otherwise below regulatory levels to permit onsite disposal of residual material per local governing standards. The method reduces the cost of removal of contaminations, trucking and offsite licensed disposal of materials and reduces the environmental impact of offsite hazardous material disposal. The method may also reduce employee interactions and public interactions with the contaminants.
[00015] Method 100 is depicted in FIG. 1. In step 102, soil debris is removed from a local environment and placed in a specialized container, such as the specialized container 200 depicted in FIG. 2. A cross section side view of the specialized container 200 is provided in FIG. 3. A front view the specialized container 200 is provided in FIG. 4. In FIG. 2, the specialized container 200 has an intake port 202, a drain port 204 and a rotating drum 206 disposed within the specialized container 200. The rotating drum 206 rotates in a clockwise rotation (see FIG. 4) or in a counter-clockwise rotation by operation of a motor 214. The rotating drum 206 is equipped with a screen 208 on an inner surface of the inner circumference that functions as a sieve. The screen 208 is interchangeable such that a particular screen can be placed in the specialized container according to the desires of a user. Such a configuration permits the user to select a screen with a sieve size that is appropriate to a given batch of soil debris. The soil debris may be removed from the local environment by vacuum truck, excavation, hydraulic excavation, sludge/slurry pump, for example and subsequently placed in the specialized container 200. The soil debris is placed into the specialized container 200 through the intake port 202 or through an alternate opening such as a hinged door.
[00016] Referring again to FIG. 1 , in step 104, a rinse solution is added to the specialized container 200 through intake port 202 to produce a slurry. In one
embodiment, the rinse solution is fresh water. In another embodiment, the rinse solution comprises chemical additives and water (e.g. chelating agents such as amino acids, citric acids, porphin, citrate, EDTA (ethylenediaminetetraacetic acid), EDDS
(Ethylenediamine-NN'-disuccinic acid), a hydrous manganese oxide (HMO), a humic acid, and the like) for removing contaminates. A sufficient volume of rinse solution is added to cover the soil debris entirely. The mix of chemical additives and water is dependent upon the efficacy of the screen and quantity of contamination. Generally, the more contaminated the soil debris, the greater the concentration of the chemical additives. The rinse solution volume is dependent upon mesh size of the screen and the composition of the soil debris. Generally, the smaller the mesh size the greater the volume of rinse solution. Similarly, the smaller the particles in the soil debris, the smaller the mesh size. In one embodiment, the user's goal is to minimize the volume of solution utilized while still providing adequate coverage of the soil debris. The used solution may also be filtered thus leaving a small portion of contaminates for subsequent disposal. In step 106, the rotating drum 206 defines a cylindrical cavity that is rotated about a longitudinal axis 212 to agitate the slurry formed in step 104. The rotation occurs through at least a portion of a full rotation (e.g. at least a portion of 360 degrees). In one embodiment, the rotation is continuous in the same direction. In other embodiments, the rotation is oscillatory in sequential opposing directions such that the cylindrical cavity is shaken. Examples of suitable rotation parameters include a rotation rate of between 5 rotations per minute (RPM) and 100 rpm for a rotation duration of between 3 minutes and 60 minutes. In one embodiment, the rotation rate is initially slow to allow the rinse solution to bond with any contaminates. Most of the rinse solution is subsequently removed by spinning at a higher rate of rotation.
[00017] In step 108, a valve is actuated to permit liquids in the slurry to exit through the drain port 204 and then be gravity drained or pumped to a solution recovery tank 400 (see FIG. 4). The rinse solution may then be re-used or disposed. Due to the presence of the screen 208, only liquids and small particles exit through the drain port 204. The mesh size of the screen 208 may be selected dependent on the specific application but will generally have a mesh size of between 3 microns and 10,000 microns. The attached FIG. 5, FIG. 6 and FIG. 7 show charts for sieve and micron sizes that may be selectively utilized depending on the contaminant and nature of the soil debris.
[00018] In step 110, a partial drying step is executed. In one embodiment, the rate of rotation of the drum 206 is increased to greater than 100 rpm such that residual wet slurry is pressed against the screen 208 and additional water is removed from the residual wet slurry. In another embodiment, the rate of rotation is increased to between 100 rpm and 3000 rpm. Additionally or alternatively, as shown in FIG. 3, a drum press 300 may be actuated and moved along the longitudinal axis 212 of the rotating drum 206 to compress the reclaimed soil debris and remove the additional liquid. The additional liquid may be separated from the reclaimed soil debris through the drain port 204.
[00019] After the remediation process, the reclaimed soil debris may be removed in step 112 from the specialized container 200 through the drain port 204 (after removal of the screen 208) or an alternate opening such as a hinged door and placed in a mixing unit 210 or simply returned to the local environment. In one embodiment, the mixing unit 210 comprises an open top, steel, leak proof tub commonly used for mixing. In one such embodiment, mixing is accomplished by using a motorized screw source for mixing, or an excavator is used for manual mixing. In one embodiment, a hinged door 302 is opposite the drum press 300 such that the drum press 300 can push reclaimed soil through the hinged door.
[00020] In those embodiments where the reclaimed soil debris is placed in the mixing unit 210, solidifying agents may be added. Examples of solidifying agents include peanut shells, pecan shells, polymers, fly ash or cement for disposal purposes. For on-site re-introduction, of remediated material, lime and dry soil can be added to stiffen and balance the pH levels of the partially dry material. Solidifying agents are used to stiffen the remediated material for either on-site re-introduction or loading into specialized containers for disposal. Alternatively, the liquids collected from the drain port 204 may be collected in a waste container for subsequent treatment and disposal.
[00021] As shown in FIG. 8, in one embodiment, a vehicle-mounted unit 800 is delivered to the location of concern. The vehicle-mounted unit 800 includes the specialized container 200, the mixing unit 210, and/or the solution recovery tank 400. These may be fixedly attached to the vehicle-mounted unit 800 or they may be removable from the vehicle-mounted unit 800. FIG. 8 shows one such vehicle-mounted unit while FIG. 9 shows an impoundment 900 with sludge/solids being evacuated out of the impoundment by a vacuum truck 902. FIG. 9 also shows the flow of material to a vehicle-mounted unit 904 and mixing unit 906 (if desired, depending on material being processed). FIG. 10 shows the rinse solution being evacuated via pipe 1000 by gravity or pump to a solution recovery tank (may be truck mounted) for re-use in the batch process or collection for treatment or disposal. An auger 1002 can be used to transfer remediated soil to a mixing unit.
First exemplary embodiment
[00022] A specialized container is brought to a local site where onsite soil debris is to be remediated to reduce or eliminate contaminants in the soil debris to permit local disposal of these contaminants by reducing the contaminant level, including radium, from the soil debris to standards at or below governing regulatory allowances. In one embodiment, the specialized container has a drum press. In another embodiment, the specialized container is free of a drum press.
[00023] The soil debris is collected and injected into the specialized container. The specialized container has a screen. Fresh water and/or select chemicals are injected into the specialized container to form a slurry. These select chemicals are relevant to the soil debris needing to be remediated. For example, arsenic in soil debris can be reduced or removed by using a blend of an amino acid and citric acid in the rinse solution. The concentration of each select chemical is dependent on laboratory test data. Another example may be chloride removal/reduction from soil debris where fresh water flushing is all that is needed.
[00024] The slurry is agitated and finer particulates and liquids are drained leaving larger particulates (based on screen size) and reclaimed soil debris. The remaining larger particulates are then compressed by a drum press or spun out. The remaining
contaminated liquids along with the added chemicals are drained from the bottom of the specialized container and collected in a waste container for subsequent treatment and disposal. The waste container is then sent to a waste treatment facility. Advantageously, the soil debris was never transported to a treatment facility.
[00025] The reclaimed soil debris is extracted from the specialized container and placed into a mixing unit where the reclaimed soil debris may or may not be mixed with solidifying agents and tested to determine the remaining residual contaminant level. If desired, the method is repeated in order to accomplish further remediation of material to acceptable governmental environmental regulatory levels.
[00026] The reclaimed soil debris is then dispensed into waste disposal or holding containers, reused, or returned to the ground/ environment as permitted by governing regulations.
[00027] Advantages that may be realized in the practice of some of the
embodiments of the described systems/methods/ devices include the following (1) contaminated materials that presently must be hauled offsite to designated license disposal sites may now be disposed of locally or onsite and; (2) such onsite or local disposal of remediated materials results in large cost savings to contractors, more environmentally friendly remediated material, and less exposure of the public to materials transported offsite over public transportation routes; (3) cost savings include trucking costs, permitting and disposal costs, and fuel use over extensive distances that un-remediated contaminated material needs to be transported for proper licensed disposal; (4) safety advantages include less exposure of workers to contaminated materials, including radium emissions, less exposure of public to hauled offsite transportation and materials, and less pollution from both hauling vehicle emissions and disposal at central licensed offsite facility, many times in a distant location from the construction site; (5) remediation equipment is portable, can be brought directly to a job site and materials remediated on local site, thus allowing most remediated materials to thereafter be disposed of on local site. This eliminates numerous truckloads of non-remediated material being handled and hauled over local roads by large construction vehicles resulting in less road damage and usage and danger to the public from increased truck traffic over local roads. It also eliminates long hauls of materials from a job to a licensed hauling materials disposal facility which may be located hundreds of miles from a particular construction site; (6) there are significant transport and material handling and disposal costs which can be reduced utilizing this method and significant environmental benefits may also be realized by remediating and disposing of materials locally as compared to hauling contaminated materials to far away disposal or land fill sites.
[00028] A benefit to be realized from the ability to store or leave the solidified material in a covered containment on-site is to allow for laboratory data and local governing approvals to be reviewed and returned. A benefit of the disclosed method is it allows for fast coordination and planning concerning the contaminated material from the available laboratory data. This allows for fast determination of what solution to use (if any) for the remediation of the soil. Also, a benefit of the disclosed method is that it allows for faster cleanup of contaminated soils compared to traditional long term monitoring and development plans involving adding solutions and additives to the ground. Examples are superfund sites where long term plans have allowed the contaminants to spread out of the localized areas. Immediate cleanup allows for less exposure to the public and animals compared to a long term exposure found typical at super fund sites. Another benefit is the cost savings from cleaning the soil immediately where quite often companies utilize the cost savings to them by using the ability to claim it as a superfund site. Often the government and tax payers are tasked with the cleanup costs after the superfund has been initialized.
[00029] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
Removal of Radium-226 and Radium-228
EXAMPLE 1
[00030] Equipment used (1) 5 gallon outer pail (plastic) solid; (2) 5 gallon inner pail (plastic) with drain holes; (3) 100 Micron Neoprene Filter; (4) Standard Garden Hose with 9 inch (22.9 cm) metal tip. Steps and Results for Radium Reduction:
Background radium levels were determined onsite (zero). A first pail (with holes) was filled with soil debris (108 microRehm). A second pail (without holes) was filled with fresh water. A first pail was placed within the second pail and mixed with 9 inch (22.9 cm) wand for 5 minutes. The first pail was removed from second pail and let liquids drain through holes. Radium levels of liquid from drain (64 microRehm) were recorded. Excess water was squeezed out by applying pressure by hand on top of the material. New radium levels of reclaimed soil debris (88 microRehm) were recorded. This example shows radium levels can be reduced from 109 microRehm to 88
microRehm using a single gravity filtering step.
EXAMPLE 2
[00031] The sample of Example 1 was subjected to a second round of processing. Using 5 gallons of fresh water were added to the once-treated soil debris and stirred for 5 minutes with a paddle. Radium levels of liquid from second drain (80-90 microRehm) were recorded. Recorded new radium levels of reclaimed soil debris (24 microRehm). This example shows radium levels can be reduced from 109 microRehm to 24
microRehm using two sequential gravity filtering step. EXAMPLE 3
[00032] Equipment used: (1) 5 gallon outer pail (plastic) solid; (2) 5 gallon inner pail (plastic) with drain holes; (3) Outer pail had steel grate on top and inner pail was placed atop of the steel grate; (4) Mixing paddle (type used for drywall mud mixing); (5) 100 Micron Neoprene filter; (6) Block of wood cut beveled to use as hand press. Steps and Results for Radium Reduction: The inner pail was filled with soil debris (300 microRehm) and the outer pail (without holes) was filled with fresh water. The pail was placed within outer pail and mixed with paddle for approximately 3 minutes. The first pail was removed from second pail and let liquids drain through holes. The material was pressed with wood block by hand. New radium levels of reclaimed soil debris (30 microRehm) were recorded which were significantly below regulatory standard. This example shows radium levels can be reduced from 300 microRehm to 30 microRehm using a single gravity filtering step if the slurry is agitated.