Process, system, and apparatus for reducing environmental contaminants from mobile phases

Abstract

This disclosure relates to reactive media containing brominated sorbents capable of adsorbing environmental contaminants, including mercury, and preventing or limiting the loss of the adsorbed contaminants in the presence of a moving medium. Systems, devices, and processes utilizing this adsorption and retention in the presence of a flowing medium are described.

Description

Technical Field

[0001] Cross - reference to Related Applications This application, filed on May 11, 2021, under 35 U.S.C. § 119(e), claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63 / 023137, filed on May 11, 2020, entitled "PROCESS, SYSTEM, AND APPARATUS FOR REDUCING ENVIRONMENTAL POLLUTANTS FROM A MOBILE PHASE", the entire content and matter of which are incorporated herein by reference as if fully set forth below.

[0002] Various embodiments of the present disclosure generally relate to processes, devices, and systems for rehabilitating a mobile phase. In particular, it is useful for removing contaminants from a mobile phase to protect the mobile phase flow to a less contaminated or uncontaminated location, and is particularly effective for mobile phases with non - neutral pH.

Background Art

[0003] Many contaminants are known to be toxic to humans and the environment. Mercury, one of these known environmental contaminants, is classified as one of the priority hazardous substances by the Agency for Toxic Substances and Disease Registry ("ATSDR"). A number of sites contaminated with mercury are listed in the United States National Priorities List (NPL). Such sites include various substances, including solids (e.g., soil, debris, waste, and other solids), liquids (e.g., groundwater, lakes, ponds, and other liquids), and combinations of solids and liquids (e.g., sediment, slurry, deposits, and other combinations of solids and liquids). Most of these sites have not been decontaminated to remove mercury. Unacceptable levels of mercury or mercury compounds may also be present in locations not listed in the NPL. Similar concerns exist for other environmental contaminants.

[0004] One factor that raises concerns about some remediation technologies is the nature of environmental pollutants to move (or leach) from their location after they have been isolated or stabilized. The U.S. EPA also regulates this, and has the Toxicity Index Leaching Method (TCLP), a test designed to determine the mobility of both organic and inorganic analytes present in liquid, solid, and multiphase waste.

[0005] Novel processes and applications for reducing environmental pollutants are disclosed in PCT / US2019 / PCT / 030729, filed on 3 May 2019, and the entire contents of that file are incorporated herein by reference. During the development and application of the processes, the need for situations in which liquids may flow or move through environmentally contaminated sites and transport environmental pollutants beyond those sites was recognized. Indeed, one of the challenges in remediating contaminated sites is that groundwater, storm runoff, and other liquid flows may transport environmental pollutants beyond the boundaries of their site or location, and there remains a need in the industry to prevent these flows from transporting pollutants. [Overview of the Initiative]

[0006] Various embodiments of this disclosure generally relate to processes, apparatus, devices, and systems for removing environmental pollutants from a mobile medium, mobile phase, or mobile flow.

[0007] One embodiment of the present disclosure is a remediation device for removing environmental pollutants from a mobile phase, comprising one or more channels through which a medium flows, and one or more solid structures adjacent to the channels. The device may include a reactive medium on the solid structure, wherein the reactive medium contains a halogen-containing adsorbent.

[0008] One embodiment of the present disclosure is a system for remediating a place, the place having an environmental contaminant and a mobile phase for remediation, the system may include a contaminated mobile phase flowing from a place of environmental contaminant, a treated mobile phase, and a remediation device between the contaminated mobile phase and the treated mobile phase, configured and positioned to capture the flow of the contaminated mobile phase.

[0009] One embodiment of the present disclosure may be a process for removing or reducing environmental contaminants from a mobile medium. The process may include incorporating a remediation device between a first position and a second position, wherein the first position contains a higher level of contaminants than the second position, and the mobile phase has the potential to flow from the first position to the second position, or does flow, and flowing the mobile phase to the remediation device.

[0010] One embodiment of the present disclosure may include, but is not limited to, a remediation device that is part of the system described above or within the process described above. The remediation device may be for removing environmental contaminants from the mobile phase. The remediation device may have one or more channels through which a medium flows, one or more solid structures adjacent to the channels, and a reactive medium on the solid structures.

[0011] In one embodiment of the present disclosure, the repair may further include a support surrounding a solid structure and a reactive medium.

[0012] In one embodiment of the present disclosure, the reactive medium may include a halogen-containing adsorbent. The reactive medium may be a bromine-containing adsorbent; a carbonaceous adsorbent; a halogen-containing carbonaceous adsorbent; a bromine-containing carbonaceous adsorbent; or bromine-containing activated carbon.

[0013] In one embodiment of this disclosure, the mobile phase may have a non-neutral pH. In some embodiments, the mobile phase may have a pH less than about 6.5. In other embodiments, the mobile phase may have a pH greater than about 7.5.

[0014] Prior embodiments of this disclosure may include the environmental pollutant comprising a toxic metal, a toxic metal compound, or a toxic metal salt; or the environmental pollutant comprising elemental mercury, a mercury compound, or a mercury salt.

[0015] Prior embodiments of this disclosure may include repair devices, which are reactive caps, permeable reaction barriers, wattles, or purification columns.

[0016] Prior embodiments of this disclosure may include a moving medium, including plumes, surface water, overlay water, pore water, groundwater, tailings water, site runoff, and other formations within a sewage site. [Brief explanation of the drawing]

[0017] [Figure 1] A repair device according to an exemplary embodiment of the present disclosure is shown. [Figure 2] A repair device according to an exemplary embodiment of the present disclosure is shown. [Figure 3] A repair device according to an exemplary embodiment of the present disclosure is shown. [Figure 4] A system according to an exemplary embodiment of this disclosure is shown. [Figure 5] A system according to an exemplary embodiment of this disclosure is shown. [Figure 6] A column setup for long-term stability testing of adsorbed mercury, according to an exemplary embodiment of the present disclosure, is shown. [Figure 7] The graph shows the cumulative mercury loss in waste liquid during a stability test conducted according to an exemplary embodiment of the present disclosure. [Figure 8]Graph showing mercury concentration (μg / L) in leachates from soil after 7, 28, and 40 days for various adsorbents, according to an exemplary embodiment of the present disclosure. [Figure 9] Showing low loss of bromine in leachates, according to an exemplary embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0018] Although the preferred embodiments of the present disclosure are described in detail, it will be understood that other embodiments can be envisioned. Therefore, the present disclosure is not intended to be limited in its scope by the following description or the details of the structure and arrangement of the components shown in the drawings. The present disclosure can be other embodiments and can be implemented or executed in various ways. Also, specific terms are used for clarity in describing the preferred embodiments.

[0019] It should also be noted that when used in this specification and the appended claims, the singular forms "a", "an", and "the" include the plural referents unless the context clearly dictates otherwise.

[0020] Also, for clarity in describing the preferred embodiments, terms are used. Each term is intended to encompass the broadest meaning understood by those skilled in the art and includes any technical equivalents that operate in a similar manner to achieve a similar purpose.

[0021] Ranges can be expressed herein as "about", or "approximately", from a particular value, and / or to another particular value. When such a range is expressed, other embodiments include from one particular value and / or to another particular value.

[0022] "Comprising" or "including" means that at least the named compound, element, particle, or method step is present in the composition, article, or method, but excludes the presence of other such compounds, materials, particles, or method steps, even if those other compounds, materials, particles, or method steps have the same function as the named one.

[0023] Furthermore, it should be understood that reference to one or more method steps does not preclude the existence of additional method steps between those explicitly identified steps, or method steps intervening between them. Similarly, reference to one or more components in a device or system does not preclude the existence of additional components between those explicitly identified components, or components intervening between them.

[0024] This disclosure generally relates to devices, systems, and processes or methods for reducing environmental pollutants or preventing environmental pollutants from leaving a place or location. This disclosure includes applications of halogenated adsorbents within devices, systems, methods, and processes that capture environmental pollutants and prevent further elution or migration of the environmental pollutants into a mobile phase flowing around, through, or otherwise past the halogenated adsorbent.

[0025] The overall absorption capacity of the adsorbent for sorbates may be an important factor in material selection. If the sorbate does not have affinity for the adsorbent in the first example... This application may have problems. The adsorbent can eventually reach its maximum capacity for sorbate, for example, become saturated, and the sorbate may eventually destroy the adsorbent. However, even before saturation of the adsorbent with sorbate, the desired adsorbent should not lose its ability to hold sorbate under operating conditions.

[0026] This issue is particularly true when the mobile medium, or mobile phase, flows through the absorbed sorbate. A challenge in any absorption process is that the sorbate can reach some equilibrium between the adsorbent and the mobile phase flowing through or across the adsorbent. If the sorbate spends time passing between the mobile phase and the adsorbent phase, it can move downstream along the flow of the mobile medium and eventually escape from the adsorbent material. For remediation, this mobility can be a significant problem if the contaminant can reach equilibrium between the flowing fluid and the adsorbent surface. In environmental settings, any mobile phase can therefore pose a challenge to the adsorbent material.

[0027] Furthermore, in many operations, for example, in industrial, construction, demolition, mining, and remediation sites, the pH of the mobile phase is not always neutral, making adsorbents that can withstand problematic mobile phases, such as those with high or low pH, particularly valuable.

[0028] The process disclosed in PCT / US2019 / PCT / 030729 involved a halogenated adsorbent that we continued to develop. In testing the application of this disclosure to environmental challenges, we demonstrated that it not only completely adsorbs contaminants but also does not have significant weaknesses in the loss of adsorbed contaminants when challenged in a series of transport media. As described in Example 1, one aspect of the product involves a halogenated activated carbon adsorbent with adsorbed environmental mercury. When challenged with liquid flows of neutral pH water, pH 4 water, and pH 8-11 water over 40 days, no mercury was released from the adsorbent. In contrast, powdered activated carbon, one of the common materials used in remediation techniques, showed mercury leaching in just 4 days during a neutral pH flow.

[0029] The reactive medium, also referred herein as a restorative agent, may in some cases be a halogen-containing adsorbent, referred herein as a "halogenated adsorbent." Halogen-containing adsorbents are typically formed from one or more halogen-containing compounds and one or more substrate materials. Many substrate materials, particularly activated carbon, are available or can be obtained in a wide range of particle sizes from nanometers to centimeters.

[0030] Accordingly, this disclosure provides processes for reducing the environmental availability of environmental pollutants, particularly at locations where a mobile phase or mobility exists. As used herein, the term “reduction of environmental availability” means stabilization, immobilization, fixation, encapsulation, separation, containment, destruction, detoxification, decomposition, and decomposition, reduction in quantity, reduction in mobility, and / or reduction in the mobility of at least one environmental pollutant. Stabilization and / or immobilization can be carried out in a medium. Reducing the environmental availability of environmental pollutants reduces their bioavailability and, therefore, their bioaccumulation.

[0031] As used herein, the term “environmental pollutant” means a chemical element or compound, or mixture thereof, known to be harmful to humans and / or adversely affect the environment (ecosystem). Environmental pollutants are typically regulated by one or more government agencies. Examples of environmental pollutants include all forms of mercury (e.g., elemental mercury, organic mercury compounds, and inorganic mercury compounds); other organic substances (e.g., hydrophobic organic compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, dioxins, furans, and / or chlorinated pesticides, but not limited to these); hazardous elements, organic and inorganic heavy metal compounds (e.g., As This includes, but is not limited to, compounds containing Pb, Zn, Cu, Cr, and / or Cd; as well as other environmental pollutants well known to those skilled in the art.

[0032] Throughout this document, terms such as “treated,” “contacted,” and “restored” indicate that a halogen-containing adsorbent interacts with a substrate containing one or more environmental pollutants in a manner that reduces the environmental availability of one or more environmental pollutants.

[0033] A device, system, or process may include a repair device having one or more channels, one or more solid structures, and a reactive medium on the structures. The repair device may have channels that are large or small and discoverable between solid structures. For example, the channels may include spaces between straws in a bundle of material, or they may be much smaller than the spaces between particles housed in a column or other structure. The channels may exist in the spaces between solid structures that form the support structure of the device.

[0034] The repair device may also include a support that surrounds and holds one or more solid structures and a reactive medium. The support may have one or more inlets and outlets through which the mobile phase can pass. One or more inlets and outlets may be typical openings inside the support, on the bottom, top, and sides, or may include mesh material such as a mesh bag.

[0035] As an example, the repair device 100 in Figure 1 may include a solid structure 101, such as sand or other particulate material, and a reactive medium 102 supported by the solid structure 101. A channel 103 within the repair device can be found between the solid structure 101 and the reactive medium 102. Next, a mobile phase 104 passes through the channel, bringing it into contact with the reactive medium. Similarly, the repair device in Figure 2 may have a solid structure 201, such as straw or fibrous material, and a reactive medium 202 supported by the solid structure 201. A channel 203 within the repair device can be found between the solid structure 201 and the reactive medium 202. Next, a mobile phase 204 passes through the channel, bringing it into contact with the reactive medium.

[0036] Another example of a repair device can be a cylindrical container, such as the one shown in Figure 3. The container is not limited to a cylinder and can be any three-dimensional shape. The repair device 300 may include a solid structure 301, a reactive medium 302, a channel 303, and a mobile phase 304. The device in Figure 3 also shows a support 305, which can be a solid or porous material as described above. As indicated by the arrows in Figure 3, the mobile phase can enter the device from the top, but it can also enter from the bottom. Alternatively, although Figure 3 is shown as a cylindrical shape with top and bottom openings, the support can be a porous material, and the mobile phase can instead flow from the sides.

[0037] The reactive medium on the solid structure may be a halogen-containing adsorbent as described herein. The reactive medium includes bromine-containing adsorbents, carbonaceous adsorbents, halogen-containing carbonaceous adsorbents, and / or bromine-containing activated carbon.

[0038] The mobile medium can also be described as the mobile phase, mobile flow, liquid phase, or liquid medium. For environmental remediation and environmental pollution, the mobile medium generally includes water, such as aqueous solutions, but does not rule out the presence of organic compounds or solvents, which may be common at the remediation site. Examples of mobile mediums include plumes, surface water, topsoil water, pore water, groundwater, tailwater, local rainwater, and / or rainwater.

[0039] Because the mobile phase does not have a neutral pH, i.e., does not exist at pH 7, environmental remediation of the mobile liquid flow can be difficult, especially for current products. These contaminated locations often have an acidic pH, and more often an alkaline pH, and these liquids often need to be treated or neutralized. Otherwise, contaminants absorbed by the adsorbent can easily detach, leading to leaching or breakthrough of environmental contaminants from the adsorbent. In contrast, the remediation devices of this disclosure can be resilient to non-neutral mobile phases and resistant to leaching of environmental contaminants when the pH is acidic or alkaline. Thus, the mobile medium or mobile phase can have a non-neutral pH. The pH of the mobile phase can be at least less than pH 6.5, less than pH 6.0, less than pH 5.5, or less than pH 5.0. The pH of the mobile phase can be at least greater than pH 7.5, greater than pH 8.0, greater than pH 8.5, greater than pH 9.0, or greater than pH 9.5.

[0040] Environmental pollutants may be any pollutants described herein. Environmental pollutants may include toxic metals, toxic metal compounds, or toxic metal salts, or they may include elemental mercury, mercury compounds, or mercury salts.

[0041] Adsorbent materials applicable in this specification include carbonaceous materials and inorganic materials. Suitable carbonaceous materials include, but are not limited to, activated carbon, carbon black, charcoal, and coal. A preferred carbonaceous material is activated carbon, which can be used in many forms, including, but is not limited to, powder, granular, or extruded, and has a high specific surface area.

[0042] Suitable inorganic materials include inorganic oxides (e.g., alumina (amorphous and crystalline), silica, magnesia, and titania); natural zeolites (e.g., chabazite, clinoptilolite, faujasite); synthetic zeolites (e.g., zeolites with a high Si:Al ratio such as synthetic chabazite (ZSM-5, beta-zeolite, sodalite), zeolites with a moderate Si:Al ratio (Y-zeolite, A-zeolite), silica-alumina phosphate (SAPO) zeolite, ion-exchange zeolites, uncalcined zeolites); clay minerals (e.g., kaolin, kaolinite, bentonite, montmorillonite); inorganic hydroxides (e.g., iron hydroxide); mixed metal oxides (e.g., hydrotalcite, metallized bilayer clay); diatomaceous earth; cement dust; hydrogenation catalysts including catalysts on a substrate (e.g., alumina, silica, or titania); CaCO3; and any combination of two or more of the above. Preferred inorganic materials include inorganic oxides (especially silica), natural zeolites (especially chabazite), and clay minerals (especially kaolinite and bentonite). CaCO3 is also a preferred base material.

[0043] The halogen elements in halogen-containing adsorbents may be fluorine, chlorine, bromine, iodine, or a mixture of any two or more halogens. Bromine is a preferred halogen. Suitable halogen-containing compounds include, but are not limited to, elemental iodine and / or iodine compounds, elemental bromine and / or bromine compounds, elemental chlorine and / or chlorine compounds, elemental fluorine and / or fluorine compounds, and other suitable halogen compounds, as is well known to those skilled in the art. Types of halogen-containing compounds that can be used include hydrohalic acids, alkali metal halides, alkaline earth halides, and ammonium halides.

[0044] Hydrohalic acids include hydrogen chloride, hydrogen bromide, and hydrogen iodide. Alkali metal halides include sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, potassium bromide, and potassium iodide. Alkaline earth halides include magnesium chloride, magnesium bromide, calcium chloride, It also contains calcium bromide. Ammonium halides include ammonium chloride, ammonium bromide, and ammonium iodide.

[0045] Preferred halogen-containing compounds include elemental bromine, hydrogen bromide, sodium chloride, sodium bromide, potassium iodide, and calcium bromide. Bromine-containing compounds are preferred halogen-containing compounds. More preferred are hydrogen bromide and elemental bromine, particularly elemental bromine.

[0046] Halogen-containing adsorbents can be prepared from materials and halogen-containing compounds described in U.S. Patent Nos. 6,953,494 and 9,101,907, and International Patent Publication No. WO2012 / 071206. In some embodiments, the preferred halogen-containing adsorbent is a bromine-containing adsorbent. In some embodiments, the preferred halogen-containing adsorbent is halogen-containing activated carbon. In other embodiments, the preferred halogen-containing activated carbons are chlorine-containing activated carbon, bromine-containing activated carbon, and iodine-containing activated carbon. In preferred embodiments, the halogen-containing adsorbent is chlorine-containing activated carbon and bromine-containing activated carbon. In more preferred embodiments, the halogen-containing adsorbent is bromine-containing activated carbon.

[0047] In other embodiments, preferred halogen-containing adsorbents are chlorine-containing activated carbon and iodine-containing activated carbon. In yet another embodiment, preferred halogen-containing adsorbents are halogen-containing chabazite, halogen-containing bentonite, halogen-containing kaolinite, and halogen-containing silica.

[0048] Halogen-containing adsorbents, particularly bromine-containing adsorbents, and especially bromine-containing adsorbents, can reduce the environmental availability of contaminants in a material by means including, for example, oxidation and / or adsorption, for example, but not limited to these. Adsorption can reduce the environmental availability of environmental pollutants by reducing their mobility. Other ways in which halogen-containing adsorbents can reduce the environmental availability of contaminants include by improving the decomposition of such contaminants by surface reactions; and / or by inhibiting the formation of contaminants such as methylmercury; and / or by other mechanisms. In the processes of this disclosure, environmental pollutants adsorbed by halogen-containing adsorbents, whether applied to solids, liquids, or combinations thereof, are stabilized so that their desorption into the environment is substantially minimized.

[0049] Mercury and other environmental pollutants are adsorbed by or removed by halogen-containing adsorbents, particularly bromine-containing activated carbon. Another halogen (especially bromine) can be formed from halogen-containing adsorbents, especially bromine-containing adsorbents, specifically bromine-containing activated carbon.

[0050] Some halogen-containing adsorbents, specifically bromine-containing activated carbon, can physically and chemically adsorb mercury in different oxidation states, including elemental mercury, mercury oxide, and organic mercury. Mercury adsorbed on bromine-containing activated carbon is stable over a wide range of pH values, where "stable" means that the mercury does not separate from the adsorbent in measurable amounts after adsorption.

[0051] The disclosures herein include numerous media or locations in which environmental contamination, particularly mercury contamination, can be detected, and generally provide remediation techniques that can be used to treat contaminants detectable in these media. Not all of the listed techniques are currently well-suited for mercury remediation, but with novel modifications and the methods claimed herein, feasible remediation techniques can be achieved. These media and locations may include permeable reaction barriers, reactive caps, filter beds, adsorption tanks, reactive wattles, pumps and treats, rainwater filtration systems, and other reactive media.

[0052] Accordingly, the disclosure may also include a system for remediating a site containing an environmental contaminant and a mobile phase that can flow from a local contaminated site. The system may include a contaminated mobile phase flowing from the site of the environmental contaminant, a treated mobile phase, and a remediation device between the contaminated mobile phase and the treated mobile phase, configured and arranged to capture the flow of the contaminated mobile phase and to treat the mobile phase. The remediation device may have a channel through which the mobile phase flows, a solid structure adjacent to the channel, and a reactive medium on the solid structure. The reactive medium may be as described above.

[0053] Figure 4 shows a system with a filtration device. System 400 may include a remediation device 401 and contaminated mobile phase 402 flowing from a retention pond 403. When water from an external source such as heavy rain flows into the reservoir, the contaminated mobile phase 402 may be pushed up through the remediation device 401, but the mobile phase passes through the remediation device 401 and the treated mobile phase 404 flows out of the remediation device.

[0054] Another example can be a wattle bound with an adsorbent. Wattles can be used to prevent soil erosion or to redirect part of a runoff. Often, wattles are a temporary measure to control soil erosion during civil engineering work, but in some cases, wattles can be used for longer periods. A typical wattle can be straw inserted into a cylindrical burlap tube. In practice, wattles are placed on the ground surface perpendicular to the direction of water flow. For example, wattles may be placed in wetland areas, around soil or tailings banks, around drainage pipes, or where small streams merge with larger flows.

[0055] The present disclosure may include a wattle containing a halogenated adsorbent as a repair device, which can adsorb environmental pollutants such as mercury from water as water passes through a soil erosion barrier or wattle.

[0056] Halogenated adsorbent wattles can be a mixture of straw and halogenated adsorbent, or they can be filled with halogenated adsorbent alone. The outer tube material of the wattle can be burlap, natural fabric, synthetic fabric, or synthetic felt material. The outer tube material can also be natural or synthetic fabric or felt impregnated with activated carbon or halogenated adsorbent. The size of the halogenated adsorbent granules can usually be larger than the corrugated opening of the tube material, so the granules usually remain inside the tube.

[0057] Figure 5 shows a system with a wattle. System 500 may include a remediation device 501 along a surface over which liquid can flow. The contaminated mobile phase 502 may flow from a contaminated source 503, for example, a reservoir at a mining site. The contaminated mobile phase produced during an overflow or leakage event can be guided along a specific course by aligning its course with the wattle. Any contaminated mobile phase 502 passing through the remediation device 501, for example, passing through the wattle, can produce a treated mobile phase 504.

[0058] Another example of a remediation device is a permeable reaction barrier (PRB), which can contain halogenated adsorbents. For example, in mercury applications, a permeable reaction barrier can be used to stop the movement of mercury from a contaminated site, allowing stakeholders to comply with groundwater regulations. This can be a preferred approach for stakeholders because it is far less expensive than stabilizing or removing the source mercury. In some cases, such as tailings banks, stabilizing the source by mixing with remediation creates a risk of tailings flowing into streams or valleys. Rainwater filtration barriers are similar, but are designed to remove mercury from rainwater and stop methylation in the medium of the rainwater system. .

[0059] PRBs can be designed to adsorb or react with mobile pollutants, which in most cases are water-soluble forms of pollutants. In the case of mercury, species most likely to reach the PRB are ionic Hg +2 or in the form of organic mercury containing methylmercury.

[0060] PRBs can be designed to allow for reactivity of approximately 10 years or more. This timeframe is considered economical in the replacement of PRBs. For situations where reactivity cannot reach a substantial period, pumps and treatment technologies are alternative groundwater mitigation approaches in some locations.

[0061] Another example of a remediation device is reactive capping. Reactive caps can be frequently used to prevent contaminants from separating from contaminated soil / sediment and entering the water surface or surface water. Reactive caps can be used in a few examples, such as at the bottom of a body of water, on land, and in tailing furnaces. This can often be a much cheaper approach to meeting surface water regulations than stabilizing or removing the source mercury. In some cases, such as tailing banks, stabilizing the source by mixing while making corrections creates a risk of tailings flowing into streams or valleys, so capping the tailing furnace is an alternative.

[0062] In both reactive caps and PRBs, the technology is similar except that the cap handles water rising from the underlying medium, although PRBs can often be placed in the path of a fluid medium. Common environmental contaminants in both can be ionic metallic species, and the halogenated adsorbents of this disclosure have a verified ability to adsorb ionic / inorganic contaminants and are also resistant to the loss of contaminants as the fluid medium passes through the adsorbent.

[0063] This disclosure may also include processes for removing or reducing environmental pollutants from a mobile medium at a contaminated site. The process may include incorporating a remediation device between a first location and a second location at the contaminated site. The first location contains a higher level of pollutants than the second location. The mobile phase or mobile phase has the ability to flow from the first location to the second location, or flows from the first location to the second location. The process enables the mobile phase to flow from the first location to the second location through the remediation device. The remediation device includes the devices described above and throughout this application. [Examples]

[0064] Example 1 - Long-term stability of adsorbed mercury in a dynamic system The effectiveness of Br-PAC in stabilizing mercury in a dynamic system was studied under column flow conditions. This column study focused on the effectiveness and stability under dynamic conditions, as well as the longer-term stability of adsorbed mercury under various pH conditions. The column test method is used as part of an environmental leaching assessment for waste evaluation, beneficial use, treatment effectiveness, and site remediation. The column setup is shown in Figure 6.

[0065] This column study investigates not only the ability of two modifications (Br-PAC and PAC) to stabilize total Hg in soil and thus reduce the leaching of mercury contamination, but also the extractable inorganic mercury (Hg) from groundwater passing through the improved soil. 2+ It was also designed to test its ability to remove elemental mercury (Hg 0 Sandy soil containing ) and contaminated over many years (several decades) is collected from old munitions sites, and this is first treated with elemental mercury (Hg 0 ) contaminated it.

[0066] The contaminated soil was completely homogenized in a glove box, and Hg 0 The analysis was performed with minimal volatilization to establish baseline values ​​for mercury content, particle size distribution, water content, total organic carbon (TOC), and pH. Soil analysis showed that the soil contained 622 ± 23.6 mg / kg of total mercury in a coarse-grained (92% sand / 8% sandy mud) composition, with a water content of 9.9 ± 0.8 at a neutral pH (7.0 ± 0.2) and virtually no natural organic material (0.002 wt%). Mercury species were further analyzed using a serial extraction method according to EPA method 3200, and four commonly recognized mercury fractions were isolated. The possible mercury species from each extraction stage are listed in Table 1. Extractable (organic and oriented) and partially extractable portions are considered "mobile forms of mercury," while unextractable / non-mobile portions are considered "non-mobile forms of mercury." Groundwater contains 102 ± 5.9 μg / kg of extractable inorganic mercury. [Table 1] [Table 2]

[0067] Four reaction scenarios were tested, and each flow-through column was filled with the treated soil listed in Table 2. After a 1-day curing time for the treated soil in each column, one pore volume (400 mL) was replaced daily for 40 days using a peristaltic pump. A rise pump was used to minimize air intrusion and flow channeling. For the first 7 days, groundwater containing extractable inorganic mercury at 102 ± 5.9 μg / kg was passed through, and then the eluate was switched to acidic DI water (pH=4) to challenge the mercury adsorbed by Br-PAC, as heavy metals tend to be more mobile under acidic conditions. After 28 days, the eluate was switched to basic DI water (starting at pH8 and going up to pH11) to evaluate whether the adsorbed mercury remained mobile under severe pH changes.

[0068] Figure 7 summarizes the cumulative total mercury from eluates collected daily for 40 days. No mercury leached from 1% and 2% by weight Br-PAC treated with soil under various pH conditions for 40 days. Deviation was observed from the benchmark PAC (2% by weight) on day 4, and the cumulative total mercury in the eluate from the PAC-treated column increased significantly with changes in eluate pH.

[0069] Previous studies treating mercury-contaminated soil with Br-PAC in a batch reactor have shown that Br-PAC is effective in stabilizing all mercury fractions or converting them into the least leachy, non-extractable / non-mobile fraction. This is consistent with previous batch reactor studies. This study also demonstrates (1) the exceptional ability of Br-PAC to stabilize further mercury in groundwater entering the column, and (2) the stability of adsorbed mercury contamination, even when groundwater with a wide range of pH values ​​passes through.

[0070] Figure 8 shows the mercury concentration (μg / L) in SPLP leachate from the soil after 7, 28, and 40 days.

[0071] The stability of adsorbed mercury was further evaluated by performing SPLP leaching tests (synthetic precipitate leaching procedure, EPA method 1312) after treatment on days 7, 28, and 40. This EPA standard leaching procedure was used as one of the primary indicators of in-situ mercury stabilization success by evaluating the ability to stabilize mercury, as in many cases only unstabilized mercury leaches out during the leaching operation. SPLP is designed to mimic the leaching of contaminants exposed to normal weather conditions in situ by acid rain, simulating leaching under conditions open to the atmosphere. Both soils treated with 1% and 2% by weight Br-PAC stabilized mercury to undetectable levels (1.0 μg / kg), but mercury exceeding 10,000 μg / L leached from the soil treated with 2% by weight PAC. SPLP test results from soil samples taken from the column showed that the total mercury leached from all treated soils did not change to a measurable level after 7, 28, and 40 days of treatment (Figure 8).

[0072] Another interesting result is that all bromide leached from the eluate. The figure summarizes the Br- concentrations measured in eluates from columns treated with 1% and 2% Br-PAC. Based on the dose calculator, the 1% usage resulted in Br- leaching concentrations ranging from less than 1 ppm to near detection level (0.5 ppm). Even at 2% Br-PAC, less than 2 ppm of Br leached throughout the 40-day column study (Figure 9).

[0073] This 40-day column study successfully demonstrated the relative advantage of Br-PAC over benchmarks by showing exceptional efficiency in stabilizing all mercury species in a dynamic system. More importantly, this study confirmed the long-term stability of mercury adsorbed by Br-PAC across a wide range of pH levels.

[0074] Various bench-scale tests have demonstrated that brominated PAC can adsorb ionic mercury from aqueous solutions. In a 40-day column study, Br-PAC was observed to stabilize source mercury in contaminated soil and adsorb ionic mercury in contaminated groundwater that passed through the column during the first seven days.

[0075] SSE analysis performed on the tested brominated PAC samples showed that all forms of mercury, including ionic / inorganic and organic forms, were converted into mercury bound to non-mobile particles. This further demonstrates that brominated PAC can react with and adsorb mobile forms of mercury that come into contact with the product.

[0076] The measured volume of brominated PAC is typically 8% by weight of mercury on the particles. This volume can be approached when soil is treated with hundreds to thousands of ppm of mercury. However, even highly contaminated groundwater from contaminated sites is orders of magnitude lower than contaminated soil. For example, in a 40-day column study, the HgT in the soil was 600 ppm, while the groundwater at the same site contained 0.1 ppm (100 ppb) of inorganic substances (Hg+2). A groundwater mercury concentration of 100 ppb is a very high level of contamination. For comparison, the California drinking water standard for groundwater used as a well source is 2 ppb.

[0077] Embodiment In addition, or alternatively, this disclosure may include one or more of the following embodiments:

[0078] Embodiment 1. A remediation device for removing environmental pollutants from a mobile phase, comprising: one or more channels through which a medium flows; one or more solid structures adjacent to the channels; and a reactive medium on the solid structures. The reactive medium comprises a halogen-containing adsorbent.

[0079] Embodiment 2. A system for remediating a site, comprising an environmental contaminant and a mobile phase for the remediation of the site. The system comprises a contaminated mobile phase flowing from a site of environmental contaminants, a treated mobile phase, and a remediation device between the contaminated mobile phase and the treated mobile phase, configured and positioned to capture the flow of the contaminated mobile phase. The device has one or more channels, each having a channel through which the mobile phase flows, a solid structure adjacent to the channel, and a reactive medium on the solid structure. The reactive medium includes a halogen-containing adsorbent.

[0080] Embodiment 3. A process for removing or reducing environmental pollutants from a mobile medium. The process includes incorporating a remediation device between a first position and a second position. The first position contains a higher level of pollutants than the second position, and the mobile phase has the ability to flow from the first position to the second position, or to flow from the first position to the second position. The process also allows the mobile phase to flow through the remediation device. The remediation device has one or more channels through which the medium of the mobile phase flows, one or more solid structures adjacent to the channels, and a reactive medium on the solid structures. The reactive medium includes a halogen-containing adsorbent.

[0081] Embodiment 4. The device, process, or system according to the prior embodiment, wherein the repair device further includes a support surrounding the solid structure and the reactive medium.

[0082] Embodiment 5. The device, process, or system according to the prior embodiment, wherein the mobile phase has a non-neutral pH.

[0083] Embodiment 6. The device, process, or system according to the prior embodiment, wherein the mobile phase has a pH of less than about 6.5. The pH may be less than about 6.0. The pH may be less than about 5.5 or less than about 5.

[0084] Embodiment 7. The device, process, or system according to the prior embodiment, wherein the mobile phase has a pH greater than about 7.5. The pH may be greater than about 8.0. The pH may be greater than about 9.0.

[0085] Embodiment 8. The device, process, or system according to the prior embodiment, wherein the reactive medium is a bromine-containing adsorbent, a halogen-containing carbonaceous adsorbent, a bromine-containing carbonaceous adsorbent, or bromine-containing activated carbon.

[0086] Embodiment 9. A device, process, or system according to a prior embodiment, wherein the environmental pollutant comprises a toxic metal, a toxic metal compound, or a toxic metal salt. The environmental pollutant may be elemental mercury, a mercury compound, or a mercury salt.

[0087] Embodiment 10. The device, process, or system according to the prior embodiment, wherein the repair device is a reactive cap, a permeable reaction barrier, a wattle, and / or a purification column.

[0088] Embodiment 11. A device, process, or system according to a prior embodiment, wherein the moving medium includes plume, surface water, topsoil water, pore water, groundwater, tailings water, and / or rainwater of a location.

[0089] The embodiments and claims disclosed herein should be understood to be applicable only to the details of the structure and arrangement of components described in the specification and illustrated in the drawings. Rather, the specification and drawings provide examples of conceivable embodiments. The embodiments and claims disclosed herein are further applicable to other embodiments and can be practiced and implemented in various ways. Furthermore, the terminology and language used herein are for illustrative purposes only and should not be considered to limit the scope of the claims.

[0090] Therefore, those skilled in the art will understand that the ideas on which the specification and claims are based can be readily utilized as a basis for designing other structures, methods, and systems for carrying out the embodiments and some of the objectives of the claims presented in this application. It is therefore important that the claims be deemed to include such equivalent structures.

Claims

1. A remediation device for removing environmental contaminants from a transfer medium, the remediation device comprising: one or more channels through which the transfer medium flows; one or more solid structures adjacent to the one or more channels; and a reactive medium on the solid structures; The repair device, wherein the reactive medium comprises a halogen-containing adsorbent.

2. The repair device of claim 1 , wherein the device further comprises a support surrounding the solid structure and the reactive medium.

3. The repair device of any one of claims 1 to 5, wherein the reactive medium is a bromine-containing adsorbent.

4. The repair device of any one of claims 1 to 5, wherein the reactive medium is a halogen-containing carbonaceous adsorbent.

5. The repair device of any one of claims 1 to 5, wherein the reactive medium is bromine-containing activated carbon.

6. The repair device of claim 1 , wherein the environmental contaminant comprises a toxic metal, a toxic metal compound, or a toxic metal salt.

7. The repair device of claim 1 , wherein the environmental contaminant comprises elemental mercury, a mercury compound, or a mercury salt.

8. 10. The repair device of claim 1, wherein the repair device is a reactive cap, a permeable reactive barrier, a wattle, and / or a purification column.

9. A system for remediating a location, the location having an environmental contaminant and a mobile phase to be remediated, the system including: a contaminated mobile phase flowing from the location of the environmental contaminant; a treated mobile phase; and a remediation device between the contaminated mobile phase and the treated mobile phase, the remediation device being constructed and arranged to capture the flow of the contaminated mobile phase, the device including a channel through which the mobile phase flows, a solid structure adjacent to the channel, and a reactive medium on the solid structure; The system wherein the reactive medium comprises a halogen-containing adsorbent.

10. The system of claim 13 , wherein the device further comprises a support surrounding the solid structure and the reactive medium.

11. 10. The system of claim 9, wherein the reactive medium is a bromine-containing adsorbent.

12. The system of claim 9 , wherein the reactive medium is a halogen-containing carbonaceous adsorbent.

13. 10. The system of claim 9, wherein the reactive medium is bromine-containing activated carbon.

14. The system of claim 9 , wherein the environmental contaminant comprises a toxic metal, a toxic metal compound, or a toxic metal salt.

15. The system of claim 9 , wherein the environmental contaminant comprises elemental mercury, a mercury compound, or a mercury salt.

16. The system of claim 9 , wherein the repair device is a reactive cap, a permeable reactive barrier, a wattle, and / or a purification column.

17. A process for removing or reducing environmental contaminants from a moving medium, comprising: incorporating a repair device between the first location and the second location; the incorporating, wherein the first location contains a higher level of the contaminant than the second location, and a mobile phase has the ability to flow from the first location to the second location or flows from the first location to the second location; flowing the mobile phase through the repair device; the repair device having one or more channels through which the mobile phase medium flows, one or more solid structures adjacent to the channels, and a reactive medium on the one or more solid structures; The process wherein the reactive medium comprises a halogen-containing adsorbent.

18. 20. The process of claim 17, wherein the device further comprises a support surrounding the solid structure and the reactive medium.

19. 20. The process of claim 17, wherein the transfer medium has a non-neutral pH.

20. 18. The process of claim 17, wherein the transfer medium has a pH of less than about 6.

5.

21. 20. The process of claim 17, wherein the transfer medium has a pH greater than about 7.

5.

22. 18. The process of claim 17, wherein the reactive medium is a bromine-containing adsorbent.

23. 18. The process of claim 17, wherein the reactive medium is a halogen-containing carbonaceous adsorbent.

24. 18. The process of claim 17, wherein the reactive medium is bromine-containing activated carbon.

25. 18. The process of claim 17, wherein the environmental contaminant comprises a toxic metal, a toxic metal compound, or a toxic metal salt.

26. 18. The process of claim 17, wherein the environmental contaminant comprises elemental mercury, a mercury compound, or a mercury salt.

27. 20. The process of claim 17, wherein the repair device is a reactive cap, a permeable reactive barrier, a wattle, and / or a purification column.

Images