SYSTEM AMD METHODS FOR THE REMOVAL OF SOFT HEAVY METALS FROM

STREAMS Technical Field

The present invention relates to the field of processes for the removal of soft heavy metals, especially mercury, from gas or liquids, particularly industrial and other "waste water treatment" streams. Also included are liquid streams (run off) from mines, former industrial sites and municipal treatment systems. The intent is to be able to successfully treat any liquid stream that may contain metals such as mercury and reduce the metal concentration to acceptable levels, which will become lower with time. Also included are gas exhausts and control streams from industrial and laboratory sites or any other source that contains such metals and their compounds. The intent is to be able to successfully treat any gas stream that contains any volatile or entrained metals, metallic inorganic or organometallic compounds and reduce the concentration to acceptable levels, which will become lower with time. The current need for mercury removal makes its removal the primary focus of this work. Background Art

The importance of mercury as an environmental pollutant is extensively documented in the United States "EPA' s Roadmap for Mercury", referred to herein as "EPA Roadmap." As this report notes, mercury occurs at low levels in the earth's crust and oceans as impurities or as stable ores and is naturally emitted in small amounts. Mercury has been used by man since prehistoric times in both industrial and domestic settings. It is now known that it is a toxic, persistent pollutant.

The prior art for mercury removal have been processes designed to absorb mercury using "easily reversible" technology. The reason for the "easy reverse" has been both chemical - many things don't bind truly irreversibly to mercury - and strategically - to be able to recycle the mercury. Even chemistry that strongly binds mercury can be an incomplete removal solution, given the ever lowering demands for mercury removal and the chemical reality of the concepts of microscopic reversibility and Ostwald Ripening. As the analytical chemistry capability improves, the desire to remove mercury to ever lower levels continues. In the chemical sense the only lower limit are the limits of detection; there is really no such thing as "none". Since mercury, like many other heavy metals, tend to accumulate in biological systems, even low levels can be dangerous so the spiral down will continue.

Carbon absorption: The property of carbon in the absorptive form, either bare or activated with other chemicals, has been known for many years to reversibly absorb mercury from gases and fluids. This absorption will work with all forms of mercury and the other chemicals, such as sulfur compounds, can enhance the absorption. The problems with carbon are low capacity and weak attraction. Carbon can be inexpensive per se, but low loading translates into a higher volume and thus high cost for both the absorbent and the process (frequent bed changes; unexpected mercury "break through'; poor process control).

Ion Exchange Resins (GT-73): Organic polymers that contain moieties (e.g. -SO ₃ ^"2 ) that attract and ionically bond with cations, such as Hg ⁺² , have been known for many years and find use in water treatment processes such as "softening", the replacement of divalent cations (positively charged ions) such as Ca ⁺² which cause 'hard' water with monovalent ions like Na ⁺ . These resins, such as GT-73, will bind to mercury ions, but have no affinity for metallic mercury or organic mercury. Moreover, all the ionic attractions are weak and easily broken. A much more serious problem is that ion exchange resins have low loading capability, since the attractive moieties are necessarily a small fraction of the mass of the polymer and are not always on the polymer in such a way as to be able to interact with passing aqueous cations. Such polymers, based on petroleum products such as propylene or styrene, are innately expensive and their prices reflect oil prices. This combination of low capacity, high cost and weak attachment has made this technology largely unsuitable.

Clays and similar inorganic absorbents, both natural and man-made: Clays with absorbent properties have been used to remove mercury from aqueous liquid streams but have some of the same properties as ion exchange resins and the same deficiencies. Since clays can have high bulk densities, the loading in weight of mercury per weight of absorbent can be very unattractive.

Another technical issue is organic and organic impurities in the liquid stream that may react with an adsorbent. Inorganic impurities are almost always present and can present problems. The actual solution to those problems depends on the materials present. Organic impurities, including "biomass" from biological systems, may be present in streams to be treated. As the "EPA Report" notes methyl mercury is a particularly difficult problem.

These prior art methods are not completely satisfactory for removing mercury because conventional adsorbents have particular problems including expense, and performance issues even when they demonstrate high efficiency at removing mercury. As noted above, a key reason appears to be that the specific adsorbents work only or best with mercury in its oxidized state and

do not work very well in its unoxidized or elemental vapor state or when it is part of an organic material. The removal and entombment of mercury complicated by the fact that mercury can exist in three separate forms: the free metal, Hg ⁰ , ionic metal weakly associated with counter-ions, Hg ⁺¹ or Hg ⁺² valence state (e.g. as the chloride), and organic compounds with mercury bound to phenyl-, alkoxyalkll-, or methyl- groups. Methyl mercury is among the most hazardous forms and of most concern in "EPA". Accordingly, there is a need for a robust process to remove soft heavy metals from liquids. Disclosure of Invention

The present invention relates to a system and method to reduce the amount of a soft heavy metal in a gas or liquid stream. This modular apparatus can include a pretreatment unit to remove materials that reduce treatment efficiency and also a membrane filter to concentrate the heavy metal species. The pretreatment unit is connected to a plurality of treatment units linked in series. In each treatment unit Self Assembled Monolayers on Mesoporous Supports are reacted with the soft heavy metals in the stream. SAMMS ^® , Self- Assembled Monolayers on Mesoporous Supports, and more particularly for Thiol-SAMMS, are described by Glen Fryxell in US 6,531,224, US 6,846,554, (specifically incorporated by reference). The term SAMMS includes a variety of materials with different active ligands including Thiol-SAMMS. SAMMS with other active ligands can utilize the same apparatus to treat streams with other contaminants or different varieties of SAMMS can be combined into a single apparatus to remove multiple contaminants at the same time. Additionally, at least one of the pluralities of treatment units includes a filter or other device to substantially reduce the quantity of Self Assembled Monolayers on Mesoporous Supports from flowing from one the plurality of treatment units to another of the treatment units. Additionally, the plurality of treatment units are connected to a post treatment unit to remove the Self Assembled Monolayers on Mesoporous Supports from the stream and alternatively to recycle SAMMS back to at least one the plurality of treatment units.

Additionally, this invention provides a composition made of Self Assembled Monolayers on Mesoporous Supports retained in a plurality of cellulose ester fibrets. This composition is retained in the treatment unit to react with the soft heavy metals.

Additionally, this invention provides a method to remove soft heavy metal from a liquid. This method includes the steps of oxidizing the liquid with a primary oxidant. The oxidizing steps can include: oxidizing the soft heavy metal to an oxidized ion; and/or oxidizing mercury-bound

organic material to oxidized soft heavy metal ion and carbon dioxide; and/or removing organic contamination; and binding said oxidized soft heavy metals with SAMMS. Next the method includes separating the unbound soft heavy metal from the SAMMS for further treatment in subsequent treatment units. Additionally, the steps include adding a secondary oxidizing agent to prevent down stream biomass growth that could affect the performance of the soft heavy metal removal with SAMMS .

Detailed Description of Drawings

FIG. 1 shows a schematic of an embodiment of the present invention.

FIG. 2 shows a schematic of a multi-stage embodiment of the present invention.

FIG. 3 shows an embodiment of the present invention using ozone. FIG. 4 shows photomicrograph of cellulose acetate fibrets.

FIGS. 5 and 6 show embodiments of the present invention using hydroclones.

FIG. 7 shows an embodiment of the present invention using a membrane.

FIG. 8 shows an embodiment of the present invention using a spouted fluidized bed. FIG. 9 shows an embodiment of the present invention using an ejector- driven scrubber.

FIG. 10 shows the benefits of serial staging SAMMS.

FIG. 11 shows results.

FIG. 12 shows results overtime for Example 4. FIG. 13 shows mercury reduction in a three-tank system with ozone.

FIG. 14 shows a schematic diagram of a three stage treatment system.

FIG. 15 shows a schematic drawing of different types of fluidized beds.

FIG. 16 is a schematic drawing of an apparatus.

FIG. 17 is a schematic drawing of an apparatus.

Best Mode for Carrying Out Invention

Although the primary focus of this work is on mercury, other soft heavy metals can also be absorbed using SAMMS and the processes claimed by this patent and a list is included in the

SAMMS literature. SAMMS have a number of variations and they all work in similar ways. Moreover, the discovery and availability of SAMMS enable this technology to be used because of the relatively low cost, high loading, and essentially permanent sequestering of mercury that they

accomplish. The definition of SAMMS here includes all manufactured forms regardless of base material, active ligand, particle size or any other physical attribute including magnetic characteristics.

The nature of the liquid has a major impact on any process to remove mercury and among the important variables are pH, temperature, types of impurities and their concentrations. It is often not possible to adjust these variables to the most optimum conditions for mercury removal or equipment operability. The extremes of pH, either acidic (1) or basic (14) are more difficult for both SAMMS and equipment. The ideal pH is 7 or neutral but deviations in both directions can be accommodated. Temperature extremes are also more difficult with the added issue that the absorption slows and becomes less efficient as the temperature decreases. Higher temperature means faster absorption, up to the restraint of phase change to steam.

FIG. 1 is a schematic diagram of modular or portable units. Unit A provides a means to pretreat the waste stream, Unit Bl provide a means to treat (i.e. remove soft heavy metals from a waste stream) and Cl provides a means to post treat the waste stream to remove the SAMMS from the waste stream and/or make any other adjustments to the stream prior to releasing the stream to the discharge point. More specifically, the pretreatment step can include membranes to enhance the subsequent treatment with SAMMS.

FIG. 2 shows a multi-stage unit involving numerous treatment methods that can be used to contact SAMMS with a waste stream containing soft heavy metals. FIG. 2 shows a related system combining multiple treatment technologies (B ₁ , B ₂ , B _n ). A pretreatment unit is used to remove organic and inorganic impurities and non-dissolved solids. The pretreatment unit can also be used to oxidize the soft heavy metal as previously described.

Mercury-containing liquid streams that are to be treated frequently have organic impurities, in addition to organic mercury compounds, due to process exposure as well as fluid handling. These materials impact the removal efficiency and selectivity and are best removed. Complete oxidation to carbon dioxide and water by a powerful oxidant is the preferred treatment. Moreover, organic impurities act as a food source for the growth of biomass that can either be mobile, moving with the fluid phase or stationary or both. Frequently, stationary biomass will breakaway and proceed down stream with the flow to foul filters, equipment and the SAMMS solids. Thus fouled, the filters must be changed and the SAMMS replaced before being fully loaded. Such upsets and inefficiencies raise the overall cost of treatment and can even create out-of-compliance events.

The present invention includes a pretreatment unit that reduces impurities that can hinder the reaction of the soft heavy metal to the SAMMS. The present invention may feature oxidation in two stages, primary and secondary, and then removes the residual oxidant from the secondary stage just before absorbing the mercury with Thiol-SAMMS. The primary oxidant in the present invention is ozone which is used to treat the wastes immediately upon collection. Ozone in this role does the job of disinfection and carbon removal from the initial collection. There is no chance to grow biosludge when the initial collection system is ozonized.

Now referring to FIG. 3, ozone is generated electrically in the most efficient way, either from separately provided oxygen (tanks or generator) or air that is enhanced in oxygen concentration using gas membrane separation technology. Ozone is the most aggressive oxidizer of both inorganic and organic compounds and is used in this technology in excess, so to convert all organic materials to carbon dioxide and any inorganic compounds that can be oxidized (e.g. reduced sulfur). After the ozone treatment, there are no longer any organic or organic metallic or reduced inorganic materials present. Ozone is not stable in water, so it will decompose harmlessly to oxygen if it is present in excess, which prevents any concern about residual ozone. All the carbon-based molecules are gone, leaving harmlessly as carbon dioxide. A system to generate ozone is shown where an alternating source of high voltage 31 is used by electrodes 32 and 34 to provide a discharge across a gap 33. The discharge produces ozone from oxygen. A dielectric 35 and 37 is used to control the electrical discharge. The excessive heat of the electrodes is cooled 36 by cooling water or by air. The system is grounded at 38. In the system, the ozone and air 39 are combined with the process stream 40 containing Hg and organic liquids. In reaction vessel Bi 42, the SAMMS react with the soft heavy metals to bind the metals. The process stream 41 with reduced mercury exit the reaction vessel 42.

After the primary oxidation, there may be the addition of a secondary oxidant, chlorine at the 2 - 3 ppm level, to act as an on-going biocide. This is the technique that is used world- wide to provide potable water. The role of chlorine is to remain with the water and to prevent any chance of biological growth in the system. While it is possible, just in the case of the primary oxidant, to use many other chemicals, the ready availability, years of successful use, low cost, and assured success of chlorine make it the preferred residual oxidant.

It is understood that the presence of oxidation chemistry at the actual treatment step, which is contact of the wastes with Thiol-SAMMS to remove mercury, is not desired. The oxidants may interact with the Thiol-SAMMS to prevent absorption. The removal of the residual oxidant,

chorine, from the water is accomplished with a small carbon bed, before SAMMS treatment, the preferred embodiment. Carbon absorbs chlorine completely. This carbon bed is only large enough to absorb the chlorine and is not designed to absorb any mercury. Any mercury absorbed, will be desorbed and eventually absorbed by the down stream Thiol-SAMMS. It is possible to use anti-chlor chemicals (chemicals that destroy chlorine; widely used in pulp and paper industries) such as sodium thiosulfate if necessary. The concern is that a chemical oxidant will interfere with the Thiol-SAMMS binding sites so a carbon bed or some other antichlor is needed.

Additionally, the pretreatment step can be used to increase the mercury concentration of the liquid stream so that subsequent SAMMS treatment will have higher adsorption capacity. A membrane can be selected which prevents mercury from passing through in the permeate. By allowing liquid with only minimal mercury concentration to pass and retaining water with the majority of mercury, the concentration of mercury in a pretreatment tank will increase. When this higher concentrated solution is allowed to pass onto the treatment steps the performance of the SAMMS material will be greater. Alternatively, the same technique can be used with a chelating agent to bind to the SAMMS making it more difficult to pass through the membrane. Alternatively the same technique can be used with a gas waste stream.

In one exemplary embodiment, the present invention provides a family of specific processes, all based on SAMMS, to remove mercury from the liquid phase of a process system that is supplied as modular systems. For these technologies, there are no constraints on how the liquid and the SAMMS are brought into contact with one another. Typical processes include beds (flow of the liquid to be treated through a packed or fluidized bed of SAMMS in any direction including up flow, down flow and horizontal flows), slurry reactors (SAMMS in contact with the liquid in a stirred reactor), immobilized SAMMS (attached physically or chemically to a support) or any combination of these techniques. The fluid - solid contact must occur for the mercury to be absorbed. Processes that favor rapid mass transfer of the mercury from the fluid to the SAMMS are preferred and will be innately lower cost. As with any solid absorbent, the size distribution of the SAMMS may vary in either a controlled or non-controlled way, as to give the most advantageous absorption.

The filtration unit operations generate substantial volumes of "contaminated" waste, and if the nature of the "contamination" is persistent (heavy metals, radioactivity, etc), then the wastes require supervised disposal. A substantial advantage thus results from a filtration process that can achieve both superb filtration and minimizes wastes by recycling the filtration media and

associated structures. The recycle conditions provide for capture of any contamination. The ultimate disposal of all inorganic materials from the system is recovery or entombment. Organic materials are recycled to extinction.

Now referring to FIG. 4, commercial thermoplastic polymer ('CTP') is obtained in pellet form and converted to very high surface area filtration aid fibers, which are termed fibrets, in a way that minimizes both the polymer use and use of equipment and other chemicals. The most preferred example is cellulose acetate (CA; typical degree of substitution (DS) about 2.54) and the fibrets are generated by preparing a solution (dope) in an appropriate solvent (acetone preferred) and then adding the dope to a non-solvent, water, with highly aggressive agitation so that the dope is deformed into long, thin and small threads which solidify into fibrets as the acetone leaves the fibrets, either dissolving into the non-solvent or immediately distilling away. Alternatively, fibrets can be prepared by melt spinning or similar processes. The formation of fine fibers for filtration of very small particles is well-known technology.

Fibrets, generated in this way, are described in US Patent Nos. 4,274,914 and 5,695,647 (hereby specifically incorporated by reference), and may use other technologies familiar to those skilled in the art. The fibrets are used either as is or mixed with staple fiber, or dried and used to collect, separate from the liquid media, usually water, and maintain adsorptive properties of SAMMS. The SAMMS may be physically retained or attached to the fibret by thermal methods (hot SAMMS impinge on fibrets so to attach by melting just the surface of the CTP) or solvent methods using a cold solvent, such as triacetin if the CTP is CA. In the simplest use, a small amount of fibrets may act as a retainer for a packed bed of SAMMS, thus the ratio of SAMMS to fibrets is extremely high. The amount of SAMMS on the fibrets is at least 5 percent by weight, more preferably greater than 20 percent by weight and most preferably greater than 50 percent by weight.

In one exemplary embodiment of the present invention, after the SAMMS are spent or when the decision is made to "harvest" the SAMMS, the filters are drained, dried of excess fluid with a gas such as air and then unpacked. All these steps can be automated. It is also possible to physically separate as much as possible the SAMMS for metal recovery or for entombment. The fibrets are recycled by the same process described, above using the same equipment. New and recycle batches can be alternated or combined. For recycled batches, the dope solution or melt, is treated to remove any entrained solids by hydroclones (see below), magnetic separation, or similar

technique and the SAMMS thus recovered added to the ones for recovery or entombment. The recycling dope or melt is treated as above to regenerate fibrets.

Thus all the organic participants - CTP such as CA, acetone and any other additives used - are recycled until they are used up. In reality, polymers are degraded at rather rapid rates, depending on the nature of the polymer (CTP). Cellulose acetate has a degree of polymerization (DP) far lower than the cellulose it was derived from and further processing degrades that further. When the DP reaches a low level, it is soluble in water and will be lost with the aqueous outfall. Recognize this is a very low level of loss.

The same is true of other organics. Acetone is lost during use due to its high volatility (bp 35 C) but that can be minimized by cool condensers and carbon beds that allow acetone recycle. In "normal" filtration processes, it is not unusual to generate a pile of spent disposable filters on a daily basis. Large waste amounts may be acceptable if there are no toxic or radioactive metals present but are not acceptable here.

Other materials that can, and will, be found in the fluid to be treated with the SAMMS can and will impact the overall performance. Insolubles, other than the inorganic SAMMS, will be present from stream to stream and from time to time. Some impurities will be organic and some inorganic. The intent of the hydroclone technology, below, which teaches nonfiltration separation of solids will be to help remove such impurities from the SAMMS, should they be captured, at the time of fibret recycle. Some organic materials such as waxes, fats, and similar materials that will be captured will likewise be lost over time too. The organic materials such as CTP will be degraded with time and lost. Factors such as very high and very low pH, other than between 4 and 8 will increase the rate of that loss. It is understood that the action intended in cases of that type is to use another CTP that is not as sensitive, should these cases arise. Other polymers, such as polyolefins that can be melt phase processed, have other sensitivities, such as loss of strength and usefulness by oxidation. Other materials may degrade by other means, including ionizing radiation, where present.

The attachment of SAMMS to the fibrets as described above is a strategy to improve the use of SAMMS fines that are made as a part of their manufacture. The SAMMS fines can be separated, by hydroclone or fluidized bed or other methods, from the larger particle SAMMS and attached to fibrets by heat or solvent to give an easy-to-retain use form of these fines. Thus both normal large particles and the small fraction of fines are both used for any application and the potential problem of "fines-as-wastes" goes away.

An effective way to improve the efficiency of the removal of heavy metal ions from liquid or gaseous media is to increase the contact time between the media and the absorbent particles. To the extent that Thiol- SAMMS, as either normal particles or fines, are in the liquid flow, the removal of those absorbent particles from the mercury-cleansed liquid is best accomplished by flow systems such as cyclones that recover the solids for continued use, recovery or entombment. Such cyclones or 'hydrocyclones' are inexpensive and very effective.

Now referring to FIG. 5, in the simplest form, a hydroclone 50 or hydrocyclone is described as follows: A 'sand' separator or hydrocyclone is a device which uses centrifugal force to separate sand or other heavy particles out of water. The liquid flow into input 51 and overflow (fluid plus undersized particles) exit at 52 while underflow (oversized particles) exit at 53. A plurality of hydroclones 50 can be linked to remove particles of different sizes. The separated material drops down into a tank or reservoir where it can be removed later or in the case of in- well separators, the separated 'sand' drops into the bottom of the well. It is not a true filter, since there is no physical barrier to separate out the particles, but it is often used upstream of a filter to first remove the bulk of the contaminant, where the filter does the final cleaning. This type of design reduces the time required to flush and clean the filter. The initial use was to remove sand from pulp slurries but can be applied to solids that are not sand-like.

While hydroclones provide an advantage downstream from any SAMMS treatment operation (post-treatment), the most novel use is as the main separation operation within the SAMMS treatment process, because long residence times of SAMMS in treatment streams give us an advantage because the metal ion absorption is a rate process that depends on a number of variables. The SAMMS can be 'recycled' around and around by a bank of hydroclones and thus lower the level of residual metal ions escaping from the treatment area as well as achieve better utilization of the active absorption sites on the SAMMS.

Now referring to FIG. 6, a combination of a bank of hydroclones - a bank because each individual hydroclone is tuned for a specific particle size or density and a group or bank gives a broader range of control - followed by another filter, such as a self-cleaning tangential flow filter made of sintered metal should prove optimum. This will give maximum exposure of metal ions to SAMMS with a minimum of handling.

Hydroclones may be used to allow the separation of 'spent' SAMMS for those which are not spent, given the large density differences. The very large capacity of SAMMS with little

change in size makes 'spent' SAMMS with much higher unit density. This is an elegant way to separate the spent SAMMS for either mercury recycle or entombment.

Alternately or in addition, hydroclones may be used to separate the 'fines' fraction generated in the manufacture of all SAMMS, particularly Thiol-SAMMS which can be advantageous for a number of reasons, including the use of these fines to advantage by confining them on fibrets, as described above. Fines can be an advantage in some applications and a disadvantage in others so it is useful to have an efficient way to separate them.

Alternately or in addition, incoming aqueous liquid streams may have other non-dissolved solids that can be separated by hydroclones prior to treatment with SAMMS. The removal, and washing, of those other solids in a separate unit operation so that they are no longer contaminated with mercury or other heavy metals that SAMMS removes is a process advantage.

A modified hydroclone that combines both centrifugal and magnetic forces to better separate magnetic SAMMS is a unique feature of this technology. The hydroclone generates motive forces, and those can be enhanced by magnetic fields, appropriately applied. See our provisional patent application on magnetic SAMMS (Method to remove agents using an adsorbent attached to a support from liquid phase of a process stream).

Hydroclones can be used for other separations beyond just enhancing slurry reactors to enhance SAMMS performance. As noted above, they should be considered before any filtration unit operation to improve the filtration. Solids removed without filtration are more easily handled. The use of membranes to treat gas phase streams can provide substantial purification from other pollutant gases, such as oxides of nitrogen, sulfur and carbon, thus allowing a more simple treatment. Gas membranes separate by molecular weight, with the bigger the difference in weights the better the separation, and there can be massive differences between the metal pollutant (Hg = 200 mass units) and other pollutants (sulfur dioxide is 64 mass units). Moreover, specific membranes, referred to as pervaporation membranes, allow the removal of a volatile soft heavy metal, such as metallic mercury, from a liquid phase into the gas phase, accompanied by substantial purification.

The use of highly efficient "spouted fluidized bed" scrubbers to remove heavy metal pollutants from gas streams, using solid absorbents, is an advantage since spouted beds can handle a much wider range of solid absorbent particle sizes and are used to classify solids by both weight and size. The combination of absorption and classification in a single unit

operation, which may be in a single or multiple physical units, greatly improves the overall efficiency. The removal of the heavy spent absorbent particles while retaining the lighter fresh absorbent in a fully back-mixed fluidized bed is an advantage. Separation of other solids, such as combustion by-product char and fly ash, is also an advantage.

Removal of heavy metals from some gas streams can be further complicated by slow mass transfer of metal species from the gas to a solid absorbent depending on the conditions and impurities. A further complication is that the rate of metal uptake at the absorbent is typically not instantaneous, and yet the contact time near an absorbent can be short. Yet a further complication is that the metal may not be of the proper chemical form (ionic) for best absorption. A liquid scrubber using an ejector, driven by the liquid containing both the absorbent and oxidation chemicals to convert the metal to the best absorptive form, can achieve the proper oxidation state, superb mass transfer and sufficient absorption time. Other impurities can be treated, or not, at the same time. More specifically, the pretreatment step can include the membranes to allow specific treatment with SAMMS. Membranes are designed to separate by weight and/or size and the species can make a difference. For example, there can be massive differences between the metal pollutant (Hg = 200 mass units) and other pollutants (sulfur dioxide is 64 mass units); compare this to the separation of salt (58 units) from water (18 units). This separation allows, in the case of combustion gas treatment, the removal of low molecular weight gases impurities (oxides of carbon, nitrogen and sulfur) while concentrating the metal containing species. This allows specific, directed treatments such as the SAMMS absorption of metal-containing materials as opposed to blanket treatment of all materials at one time.

Now referring to FIG. 7 an example using membrane technology is shown, This system can receive input from devices such as the spouted fluidized bed or ejector driven scrubber to provide a low mercury permeate, or a high mercury concentrate that may be subject to further treatment. The feed stream 71 enters tank 73 where a pump 76 is used to pump the fluid across a membrane 75. The membrane retains the heavy metal in the concentrate 72 and allows the fluid and minor amounts of the heavy metal to pass 78. After the concentration of heavy metals has increased in tank 72 the valve 77 can be opened and allow the fluid with high heavy metal concentration to move on to subsequent treatments (B). The specific case of pervaporation, in which gaseous metal, mercury, is removed from a liquid stream after appropriate conversion by reduction and other chemical treatment is

taught and claimed. Pervaporation was developed to remove more volatile materials such as ethanol from water.

The further use of agents, such as chelating agents e.g. EDTA and such, to enhance membrane separation greatly improves the separation efficiency. EDTA can bind metallic ions, such as Hg ⁺² and prevent their passing a membrane, making for a much more concentrated solution. Thus such membrane filters as shown in FIG. 7 can receive input from devices such as the spouted fluidized bed or ejector driven scrubber to provide a low mercury permeate, or a high mercury concentrate that may be subjected to further treatment.

Now referring to FIG. 8, an exemplary embodiment using spouted fluidized beds is shown. A fluidized bed is used to handle SAMMS and other absorbent particles in a gas fluid, so that the resultant fluidized 'solid - gas' mixture acts as if it were a liquid. Thus it seeks its own level, just like a liquid, and can be pumped and handled like any other liquid. It also has superior heat and mass transfer, which are very important for control and absorption. Fluid beds can be run continuously or batch- wise and are ideal when a pollutant, like mercury metal or salts, is contained in a combustion gas leaving a boiler unit operation. The combustion product gas can fluidize SAMMS and this will result in absorption of mercury onto the SAMMS.

Now referring to FIG. 8, a spouted fluidized bed is shown. The use of a spouted fluid bed in the drawing, also as described in US Patent No. 4,217,127 (specifically incorporate by reference) shows gas inlet 88 and several withdrawing points (82, 83, 84, 85) that allow both new SAMMS to be added and SAMMS of different density, either due to size or degree of metal saturation, to be removed. Fine particle removal is accomplished with either a baghouse or cyclone 82. Fines from the baghouse 82 can be reintroduced into the system 81 for further adsorption of the soft heavy metal species. This drawing shows three separate gas addition points (86, 87, and 88) but it is possible to have even more. The differences in gas addition rates can give superb control in terms of fractionation based on size or mass or both. This particular unit can also add liquids, solutions and other items as necessary (such as a pump on inlet 88, for example). A single gas outlet 89 conducts the scrubbed gases on to other uses such as further treatment or use in other ways, both chemical and physical.

It is understood that it is possible to do gas treatments either before or after the SAMMS treatment, depending on what else is present and how it may be removed. Carbon, sulfur and nitrogen compounds are always candidates for removal in combustion gases.

Depending on other pollutants in the stream, it may also be logical or necessary to remove gases such as carbon dioxide and any other materials not common atmospheric gases (nitrogen, oxygen, argon) and others by membrane (described above) and similar selection processes that too can be integrated with SAMMS scrubbing. Separate scrubbing, or reaction of other pollutant gases, are far more efficient than gross scrubbing of entire streams. An example of a commercial reactor of this type is made by Buss AG, a Swiss firm, i.e.

"A loop reactor.... with a liquid circulation around the reactor being provided and being coupled with one another via an ejector mixing nozzle. To ensure completeness of the reaction and suppression of the formation of by-products..." An example of a unit is described in US Patent No. 5,159,092 (incorporated by reference). Now referring to FIG. 9, an ejector driven scrubber is shown. The ejector mixing nozzle 99 is shown in reactor 91. SAMMS and liquid are present in reactor 91. An oxidant is injected via injector 92. The pump required to run the ejector is 93. A heat exchanger 97 is shown. Spent SAMMS can be removed from the liquid, as necessary, by using the output and subsequent treatment. The soft heavy metal, liquid and SAMMS are provided via pump 93 to discharge for additional treatment through valve 98 or to recirculate through the heat exchanger 97. The clean gas output 96 enters the process stream output. If necessary such a system can be set up to run several process treatments, B _1, in series removing one or more additional metal or removing more of the mercury.

The liquid containing the SAMMS, as aqueous slurry, circulates by means of a pump 93 through an ejector and that movement generates a vacuum force that pulls gas into the ejector 99 where intimate contact between the gas, the liquid and the SAMMS occur that provides superb mass transfer from the gas to the liquid and SAMMS. A heat exchanger allows the temperature of the reaction to be adjusted for optimum absorption. Moreover, reagents such as oxidants (ozone, sodium hypochlorite, etc) can be added to the liquid to convert metallic mercury (Hg ⁰ ) or organic mercury (methyl mercury, thimerasol) to ionic mercury (Hg ⁺ ) which is the most assured species for absorption. The scrubbed gas leaves the reactor after passing through the ejector and generally through a demister screen that prevents droplet mists from being lost.

It is not necessary that a Buss system be used; it is simply one example of a how a system works. It may be desirable to use the same elements - reaction vessel 91, pump 93, heat exchanger 97 and ejector 99 - in any operating system. If the system is to run

continuously, it is necessary to have provisions for continuous addition and removal of the carrier fluid as well as new and spent SAMMS.

It is also possible to use this same system to treat or remove other pollutants that may be present in the same gas steam. For example, a power plant may have other metals present that can be removed by use of a staged set of ejector driven scrubbers. It may also be possible to remove acidic or basic contaminants by neutralization. It is possible to treat a gas, such as combustion product, so that it is then suitable for reuse in some way, such as a high carbon dioxide content being used as a source of inert gas for sale or internal use. Thus it is possible to achieve further chemical (as a neutralizing acid) or physical (to inert equipment containing flammable solvents or for carbonate beverages) or biological (green house growth enhancement) use.

Example 1 — Fixed Bed, Column

A filter system containing a specific adsorbent can be manufactured in the form of a fixed bed treatment unit. A fixed bed filter constrains the adsorbent to a fixed volume, for example by placing a fixed volume of adsorbent in a cylinder tube between two screens or sieves whose openings are too small for the adsorbent to pass. The disadvantage of such a fixed bed filter is that the adsorbent particles must be fairly large in diameter so the back pressure is not too high. Very small powder whose use is advantageous due to its higher specific surface area may also blind the screen, sieve or other porous restrained device at the top and bottom of the bed. As a result, adsorbent particles of diameter between about 0.3 to 2 mm are used regardless of the penalty in surface area. Multiple columns (B ₁ ) could be used in series to further reduce contaminant concentration.

An evaluation of a 1 mm silica functionalized with thiol-silane using the method of US Patent No. 6,531,224 to maximize adsorbent ligand density was performed using a fixed bed column. The test column was filled with 68-70 cc of 1 mm thiol-SAMMS. An 80 mesh sieve was placed on each end of the column to hold in the SAMMS. The column was fed with a contaminated water stream containing 36 ppb Hg influent solution. The pump used was a variable flow chemical gear pump. The test column was made of clear PVC and has the following dimensions ID: 0.935 " x 8.0" (90cc) cylinders. The influent water was produced using de-ionized water and mercury nitrate. The flow rate was set to 10 bed volumes per hour (11.6 ml/minute) using an Omega flow meter. There was no bed expansion in the test column. Approximately 50cc samples were pulled

from the influent and effluent after 2, 8, 16, and 24 hours and analyzed on a Tekran CVAF spectrometer.

Table 1 shows the fixed bed treatment unit can attain good reduction in mercury concentration. It drops from an input concentration of about 36 parts per billion (ppb) to 0.043 parts per billion (ppb). This demonstrates a reduction of 99.88%.

Table 1. Fixed bed influent and effluent concentration/or 1 mm Thiol SAMMS.

Hrs. lnfluent(ppb) Effluent (ppb)

2 33 0.020

8 36 0.051

16 38 0.051

24 38 0.050

Avα. 36 0.043

Example 2 — Fixed Bed, Media Filter

A fixed media filter treatment unit can achieve good reduction in contaminants such as mercury. In this type of filter the adsorbent particles are sandwiched between two other adsorbent filters. By fixing the location of the adsorbent particles the phenomenon of channeling can be avoided. The data in FIGS. 10 & 11 was collected by presenting the filter to a laboratory-prepared water stream containing 29.8 ppb ionic mercury. A single filter can reduce the mercury level only to 0.268 ppb, one-hundredth its original value. When a second filter was placed in series the mercury concentration was reduced a further 50% to 0.128 ppb. When a third filter was placed in series with the second filter, the output mercury concentration fell another -50% to 0.062ppb. A fourth filter placed in series reduced the output of the third filter 79% to 0.0127 ppb. The overall reduction in mercury concentration for the four serially staged filters relative to the input stream is 99.96%, with a decontamination factor (DF) of 2346.

Example 3 Suspended Bed A fluidized bed treatment unit has high enough rate flow of fluid that the adsorbent particles are raised or suspended by drag forces and the particle-fluid mixture behaves as though it

is a fluid. When a bed of particles are fluidized, the entire bed will expand as the fluid flow is increased. If the superficial velocity of the fluid is greater than the settling velocity of the particles, the particle will be carried out with the fluid. This should be avoided to allow the adsorbent particles to remain in the suspended bed system. The most common reason for fluidizing a bed is to obtain vigorous agitation of the solids in contact with the fluid, leading to excellent contact of the solid and the fluid. Such a filter could be used as element Bi in the current invention to further reduce contaminant concentration.

An evaluation of a 0.4 mm silica functionalized with thiol-silane using the method of US Patent No. 6,531,224 to maximize adsorbent ligand density was performed using a suspended bed column. The test column was filled with 68-70 cc of 0.4 mm thiol-SAMMS. An 80 mesh sieve was placed on each end of the column to hold in the SAMMS. The column was fed with a 33 ppb Hg influent solution. The pump used was a variable flow chemical pump. The test column was made of clear PVC and has the following dimensions ID: 0.935" x 8.0" (90cc) cylinders. The influent water was produced using de-ionized water and mercury nitrate. The flow rate was set to 10 bed volumes per hour (11.6 ml/minute) using an Omega flow meter. There was 17% bed expansion in the test column. Approximately 50cc samples were pulled from the influent and effluent after 2, 8, 16, and 24 hours and analyzed on a Tekran CVAF spectrometer. Table 2 shows, the suspended bed can attain good reduction in mercury. It drops from an input concentration of about 33 (ppb) to 0.017 (ppb).

Table 2. Suspended Bed Influent and Effluent Concentration for 0.4 mm Thiol-SAMMS.

Hrs. lnfluent(ppb) Effluent (ppb)

2 29 0.027

8 34 0.006

16 36 0.016

24 33 0.018

Avα. 33 0.017

Example 4 - Slurry Reactor, Staged Treatment, Membrane Separation, Oxidation of Organics

A three stage treatment system was built as described in the diagram in FIG. 14. The system is made of two stages of identical treatment units 104 and 113, and a single pretreatment unit, 103 and a single post treatment unit 115. The treatment unit is made of a contacting tank 105, a micromembrane filter 110 and housing, a pump 112 to pump water along with associated piping and valves. The contacting tank 105 and 114 contains a weight fraction of SAMMS® adsorbent, Steward product number THSL-01 (Steward Environmental Solution, Chattanooga, TN) of 0.5% dispersed in water. The contacting tanks 105 and 114 are provided with level control sensors (not shown) whose output controls the valves on the input and output of the contactor and to the input supply pump 112 to maintain the water level at a relatively constant value in the contacting tanks 105 and 114.

Untreated water is derived to the apparatus via delivery pipe 100. The pretreatment unit 103 is made of cartridge filters 102 to remove non-dissolved solids. Alternatively membranes can be used in the pretreatment unit to concentrate the soft heavy metal to facilitate treatment in the treatment unit. One set of piping (not shown) delivers the untreated water from the pretreatment filter to the contacting tank holding the SAMMS adsorbent. Another set of piping (not shown) connects the contactor tank to the pump 112 which pumps the water to the membrane housing. The pressure created by the pump causes a transmembrane pressure across the micromembrane (which can be selected for the characteristics of the waste water, in this case a spiral wound membrane prod # PV400B-4040KF-EI1C by Sepro was used). The transmembrane pressure causes a fraction of the water, in this case about 10% to permeate the membrane as output treated water. The membrane is so constructed with a second outlet to allow the water that has not permeated the membrane to return to the contacting tank. The pressure, size of membranes and number of membranes is selected to provide an output flow rate equal to the input flow rate. The post treatment unit is shown as 115.

The system is designed to maximize the capacity of SAMMS and minimize the overall treatment cost through the countercurrent movement of SAMMS at designated intervals. Since SAMMS and other adsorbents typically follow a Langmuir isotherm curve for their adsorption capacity the SAMMS in the first treatment unit 104 will remove the greatest amount of mercury from the stream since it has seen the highest concentration of mercury. When the system is no longer able to meet the design requirements for adsorption after the last treatment unit B _n the

SAMMS must be moved. The SAMMS in the first treatment unit 104 will be removed for regeneration or disposal. The SAMMS in the second treatment unit 113 will be moved to unit 104 (i.e. counter-current movement). If additional treatment units are included in the system the SAMMS in those units would also be moved counter-current and only the last treatment unit B _n would be charged with new or regenerated SAMMS. By using the SAMMS in this manner the highest adsorption per weight of SAMMS can be achieved thereby lowering the overall system operation cost. Additionally, at least one of the plurality of treatment units includes a filter 110 to substantially reduce the quantity of Self Assembled Monolayers on Mesoporous Supports from flowing from one the plurality of treatment units to another of the treatment units.

An industrial well water containing a high percentage of chloro-organic compounds and 1000 ppm humic compounds was presented for treatment. The chemical contaminants are shown in Table 3.

Table 3. Chloro-Organic Content of Well Water "A " of Example 4

As the system ran the output concentration of mercury began to rise as shown in FIG. 12.

At 100 hours the flow rate had fallen from almost 10 gallons per minute to less than 3 gallons per minute and the color of the water in the first contractor tank was dark black.

The test was suspended and samples of the water, the membranes and the pretreatment filters were obtained and analyzed. Examination of the membranes shows the membranes are blinded by a thin continuous coating of an organic film. FTIR analysis showed that the water contains a very high percentage of humic compounds. These compounds were blinding both the pretreatment filters and only the membrane of the first tank. Humic compounds are complex aromatic macromolecules comprised of amino acids, amino sugars, polypeptides and aliphatic compounds arising from decaying vegetation. By examining the original chemical analysis and accounting for all organic compounds reported by the original analysis, about 1000 ppm are missing, and assumed to be the humic compounds.

Samples of the water were exposed to ozone by bubbling ozone through the water from an ozone generator. The original water had a dark yellowish-brown color. After bubbling ozone through the water for a while it turned clear. A control sample which had nitrogen bubbled into it showed no color change indicating the color change effect was due to ozone not gas bubbling through the sample.

As a result of this test a second pretreatment method, A ₂ was applied to our tank system described in Example 4. A commercial ozone generator that provided suitable amount of ozone to oxidize the humic compounds was connected to the input stream.

Example 5 - Ozone Treatment.

The filtration system with three identical stages of treatment 104, 113, (not shown) preceded by a pretreatment of ozone injection was restarted and run for 350 hours. FIG. 13 shows the change in mercury concentration of the input and output over the first 350 hours of running. In this test the initial input flow rate was about 2-2.5 gallons per minute. The three stages of treatment systems reduce the mercury concentration in the input well water from and average of 1.65 ppb (μg/L) to an average of 0.00525 ppb ((μg//L) for up to 326 hours. This is a decontamination factor of 315, or a 99.7% reduction of the mercury concentration. Example 6 — Hydrocyclone, Slurry Reactor

To show a hydrocyclone' s effectiveness at separating solids (SAMMS) in a reactor system, a treatment system was comprised of a contacting tank, a Mozley C 1206 hydrocyclone assembly fitted with one 10 mm Micro spin hydrocyclone and five blanks, a pump to pump

influent water to the contactor tank, and a pump to pump the "contacted" water to the hydrocyclone. The water level in the tank was controlled by pumping the influent water at the same flow rate as the water exiting the hydrocyclone "overflow" (both set at 0.53 gpm). The contactor tank contained 0.3% weight fraction of Thiol-SAMMS on a 100 micron silica support. A volume of 13.25 gallons was maintained in the contactor throughout the experiment. The contact time was 25 minutes.

The results of the experiment indicate a 54% Hg removal. The solids content of the contactor tank remained relative steady throughout the experiment, showing the hydrocyclone' s effectiveness to separate the solids. The data is summarized in Table 4.

Table 4. Contactor tank with SAMMS Utilizing a Hydrocyclone for Solids Separation.

Influent Effluent Hg Tank Overflow d50

(overflow) removal solids solids (Microtrac

Hr. (PPb) (PPb) (%) (%) (%) (microns)

0 - - - - 93.99

1 - - 0.25 0.05 -

2 30 13 57% - - -

3 23 14 39% 0.29 0.03 -

4 28 12 57% - - -

5 22 10 55% 0.24 0.06 -

6 28 1 1 61 % 0.29 0.05 -

Avg 26 12 54%

Example 7 - Spouted Fluidized Bed

A spouted fluidized bed is a particle bed through which fluid (liquid or gas) flows at such a high superficial velocity that the particles are raised or suspended by drag forces and the particle- fluid mixture behaves as though it is a fluid. When a bed of particles are fluidized, the entire bed will expand as the gas flow is increased. If the superficial velocity of the gas is greater than the settling velocity of the particles, the particle will be carried out with the gas. This should be avoided to allow the adsorbent particles to remain in the fluidized bed system. A common reason for fluidizing a bed is to obtain vigorous mixing of the solids in contact with the gas, leading to excellent contact of the solid and the gas.

As the fluid (gas) velocity is increased, frictional force between gas and particles

counterbalances the weight of the particles, this known as minimum incipient fluidization velocity. The minimum fluidization velocity is primarily influenced by the particle diameter and density. As a result, the quantity of gas required for minimum fluidization changes as the product's particle size or density changes.

Now referring to FIG. 15, the behavior of the fluidized bed depends on the conditions and configuration of the fluidizing equipment, and properties of the solid phase, e.g., electrical resistance and magnetic properties. Various types of fluidized beds can include slugging beds 161, boiling bed 162, channeling bed 163, spouting bed 164 and bubbling bed 165. Now referring to FIG. 16, a fluidized bed column 177 has a gas inlet 176, on inlet gas sampling port 175 and a distribution plate 174. The exhaust gas connection 171 and output gas sampling port 173 are show. A 21 micron retaining screen is shown in the fluidized bed 172.

An evaluation of iron oxide functionalized with thiol- silane using the method of US Patent No. 6,531,224 was performed using a fluidized bed column as shown in FIG. 16. The thiol-SAMMS was screened to achieve a specific particle size distribution using a 100 and 270 mesh sieve which gave an average size of 100 microns. The test column was filled with 117 grams (425 cc) of thiol-SAMMS. The solids were supported by a 20 micron porous plate. The purpose of the plate (know as a "distributor" 174) is to uniformly distribute the gas across the column area. A pressurized nitrogen gas stream containing 45.5 μg/m ³ was forced through the distributor plate up through the solid particles at a flow rate of 325 cc/minute. The gas-phase elemental mercury was produced using a VICI Metronics Inc. permeation chamber (model 150) through which the nitrogen carrier gas flowed.

The fluidized bed column 177 was made of clear PVC of the following dimensions ID: 1.02" x L: 19.0". A 3" section of clear PVC was attached above and below the test column. These sections were fitted with septums for sampling the input 175 and output concentration 173. The gas velocity was increased to achieve a bed expansion of approximately 70%. Based on a visual assessment of the example described in this example, the experimental conditions produced a spouting bed 164. A 21 micron polyester screen cloth stretched across the top of the test column 172 prevented any small particles from escaping. Gas samples were pulled from the input and output after 0.4, 1.1, and 1.75 hours and analyzed on a Tekran CVAF spectrometer (Model 2600). Table 5 shows the fluidized bed attained good reduction in mercury. The concentration of

Hg(O) dropped from 45.5 μg/m ³ to 5.0 μg/m ³ .

Table 5. Fluidized Bed Input and Output Concentration for Thiol-SAMMS.

Time Input Output Hg removal

Hr. (μg/m ³ ) (μg/m ³ ) (%)

0,4 45.5 4.4 90.3

1.1 45.5 5.5 87.9

1.75 45.5 5.2 88.5

Avg 45.5 5.0 88.9

Example 8 - Liquid Scrubber.

Removal of heavy metals from a gaseous steam can be difficult as a result of slow mass transfer of metal species from the gas to a solid adsorbent. A further complication is that the metal may not be in the proper chemical species for optimal adsorption. This example shows that a liquid scrubber using a venturi type injector driven by a liquid containing the adsorbent and oxidant can convert the metal to an ionic state and achieve excellent mass transfer and adsorption ability. An evaluation of a liquid scrubber using silica functionalized with thiol- silane using the method of US Patent No. 6,531,224 was performed by injecting elemental mercury into a stream of liquid using a venturi type injector. Now referring to FIG. 17., the components of the apparatus included a 4 liter fluoropolymer-coated bottle 186 fitted with an outlet to a gear pump 189, a pressure gage 187, a Mazzei model 287 injector 183, and a return line 182 to the 4 liter bottle. The gas line feeding the injector 184 was fitted with a port to sample the incoming gas 185. The gas (nitrogen) containing gaseous elemental mercury (Hg(O)) was produced using a VICI Metronics Inc. permeation chamber (model 150). A septum fitting 190 was installed on the shoulder of the bottle as a means to inject the oxidant. The bottle cap was fitted with an outlet for exhaust gas. A sampling port 181 was installed on the outlet exhaust line. A comparison of the incoming gas mercury concentration and the outlet gas line was performed to determine the reduction of gaseous elemental mercury from the nitrogen stream.

2.5 liters of de-ionized water was placed in the 4 liter bottle. Water was circulated through the atomizing injector 183 and back to the bottle 186. The water was stirred using a magnetic stirrer. The nitrogen carrier gas containing 45. μg/m ³ mercury flowed to the injector at a rate of

325 cc/minute. The injector inlet pressure was set at 9 psi using a variable speed gear pump 189. The transfer of gaseous mercury from the gas steam to the liquid stream was determined by measuring the concentration of mercury in the input gas and output gas of the system using a Tekran CVAF spectrometer. The results indicate very little transfer of mercury (<2%) from the input liquid stream to the gas output concentration. 2.5 liters of dc-ionized water was placed in the 4 liter bottle. 12.5 grams of thiol-SAMMS was wetted with 30cc of IPA (isopropyl alcohol) and introduced into the 4 liter bottle. The SAMMS suspension was continuously re-circulated from the bottle, through the injector, and back to the bottle. The suspension was stirred using a magnetic stirrer. The nitrogen carrier gas containing 45.5 μg/m ³ mercury flowed to the injector at a rate of 325 cc/minute. The injector inlet pressure was set at 9 psi using a variable speed gear pump. The input and output gas was sampled and analyzed on a Tekran CVAF spectrometer. The results indicate over 80% mercury reduction between the input and output gas concentration.

2.5 liters of dc-ionized water was placed in the 4 liter bottle. 12.5 grams of thiol-SAMMS was wetted with 30 cc of IPA and introduced into the 4 liter bottle. In addition, 25 cc of 4-6% sodium hypochlorite (Clorox® Bleach) was also introduced into the 4 liter bottle. The SAMMS/bleach suspension was re-circulated through the injector and back to the bottle. The suspension was stirred using a magnetic stirrer. The nitrogen carrier gas containing 45.5 μg/m ³ mercury flowed to the injector at a rate of 325 cc/minute. The injector inlet pressure was set at 9 psi using a variable speed gear pump. The input and output gas was sampled and analyzed on a Tekran CVAF spectrometer. The results indicate over 99% mercury transfer of gaseous mercury from the input stream to the liquid stream. Table 6 shows that the liquid scrubber is able to attain good mercury reduction with a SAMMS addition and excellent results when both SAMMS and an oxidant are used.

Table 6. Liquid Scrubber Input and Output Concentration for Thiol-SAMMS.

Thus, it should be understood that the embodiments and examples described herein have been chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited for particular uses contemplated. Even though specific embodiments of this invention have been described, they are not to be taken as exhaustive. There are several variations that will be apparent to those skilled in the art.

Individual Applicability

The present invention can be used to remove soft heavy metals from gas combustion products, such as with coal fired power plant. Additionally, this invention relates to the removal of soft heavy metal from liquid waste treatment stream, such as in chemical processing, mining or waste management.