Abstract: An apparatus for separating solid particles from the suction effluent of, for example, a dental office, preferably driven by a dental office vacuum pump, includes a surge tank for accommodating effluent overfill connected to a sedimentary deposit tank for sedimentation of effluent particles. A bypass conduit is connected to the surge tank inlet which is equipped with a vacuum break valve for allowing air into the system when the suction openings are closed. The sedimentary deposit tank has a series of baffle chambers through which effluent flows in sequence, and in each of which chambers sediment is deposited for later removal. The surge tank preferably has a liquid level sensor and warning device. Modular filters or adsorbants may be installed in the sedimentary deposit tank, or a modular auxiliary filter may be connected downstream of the tank. Chemical injection may be used to improve sedimentation.

Abstract: The present invention is a floatation process and associated apparatus for removing heavy metal waste from various effluent water streams. The process and apparatus generally introduces a population of fine diameter air bubbles and one or more flocculating chemicals into an effluent stream to produce buoyant floc structures that include the heavy metals and that can be removed from the effluent stream. The present invention provides a reliable, cost-effective means of removing heavy metals from effluent water streams.

Abstract: A process for removing heavy metals from water is provided. The process includes the steps of introducing magnetite to a quantity of water containing heavy metal. The magnetite is mixed with the water such that at least a portion of, and preferably the majority of, the heavy metal in the water is bound to the magnetite. Once this occurs the magnetite and absorbed metal is removed from the water by application of a magnetic field. In most applications the process is achieved by flowing the water through a solid magnetized matrix, such as steel wool, such that the magnetite magnetically binds to the solid matrix. The magnetized matrix preferably has remnant magnetism, but may also be subject to an externally applied magnetic field. Once the magnetite and associated heavy metal is bound to the matrix, it can be removed and disposed of, such as by reverse water or air and water flow through the matrix.

Abstract: The disclosed invention relates to a method of disposing of mercury-containing wastewater containing mercury-complexing materials, comprising the steps of treating wastewater containing mercury ions with a strong oxidizing agent in a reaction chamber to produce pretreated wastewater by removing an effluent stream of pretreated wastewater from the reaction chamber; and passing the effluent stream of pretreated wastewater through a column packed with a mercury-selective adsorbent material to produce an effluent stream of wastewater having a reduced mercury content. The adsorbent material is a porous resin having immobilized mercury-selective chelating groups bound thereto. A particularly preferred adsorbent material is a crosslinked styrene-divinylbenzene copolymer having immobilized dithiocarbamate groups bound thereto.

Abstract: A method for improving the efficiency and usable life in a cross flow membrane filter used to remove contaminants from bilgewater. The bilgewater is passed upstream of the cross filter membrane through a fluid-pervious filtration media which has been infused with an absorbtion composition comprising a homogeneous thermal reaction product of an oil component selected from the group consisting of glycerides, fatty acids, alkenes, and alkynes, and a methacrylate or acrylate polymer component. The contaminants are thereby immobilized at the media. The purified output from the infused filtration media is then provided as input for the cross flow membrane filter.

Abstract: A method and apparatus for removing contaminants from an oily bilgewater. In the method the bilgewater is passed through a fluid-pervious filtration media which has been infused with an absorbtion composition comprising a homogeneous thermal reaction product of an oil component selected from the group consisting of glycerides, fatty acids, alkenes, and alkynes, and a methacrylate or acrylate polymer component. The contaminants are thereby immobilized at said media, and the purified bilgewater having passed through the filtration media is discharged, e.g. into a body of navigable water.

Abstract: Thiacrown polymers immobilized to a polystyrene-divinylbenzene matrix react with Hg2+ under a variety of conditions to efficiently and selectively remove Hg2+ ions from acidic aqueous solutions, even in the presence of a variety of other metal ions. The mercury can be recovered and the polymer regenerated. This mercury removal method has utility in the treatment of industrial wastewater, where a selective and cost-effective removal process is required.

Abstract: The present invention is directed to a system and method for converting hazardous speciated and elemental mercury-containing wastes to environmentally acceptable wastes by mixing the wastes in the presence of a polysulfide, water, and an mercury-reactive material, such as elemental sulfur.

Abstract: Embodiments of the present invention relate to methods and systems for removal of contaminants from aqueous solutions. The methods and systems of these embodiments are particularly suited to removal of arsenic species as well as transition-metals, post-transition-metals, phosphates and other contaminants in aqueous solutions. The methods and systems of embodiments of the present invention provide for the addition of a reagent to a contaminated solution in combination with a pressurization process and a depressurization process. Contaminant particulates and solids produced in these processes may be removed by conventional separation techniques.

Abstract: Silicon is employed as a reducing agent in an acid bath to adsorb noble metals present as contaminants in the acid. In the manufacture of silicon devices for electronic memory and other devices, polonium-210 is adsorbed by silicon getters to reduce soft error rate attributable to alpha particle emissions from the radioactive polonium. The noble metals in addition to polonium which can be plated onto silicon using the disclosed method are gold, silver, platinum, copper, palladium, mercury, selenium and bismuth.

Abstract: A method for treating in situ large bodies of water contaminated with heavy metals and having varying density stratas to immobilize the contaminant metals is disclosed. The method, or process for in situ immobilization of metals is focused on treating large bodies of water having metals therein that are also adjacent a border of soil or earthen materials in an attempt to immobilize the metals from penetrating through the soil. Initially, the density mean of the body of water is determined, which is densest typical at regions at or approaching 4 degrees C.

Abstract: Process for removing heavy metal ions from aqueous media, characterized in that, to precipitate out the heavy metal ions, a sulphide precipitation is carried out in the presence of iron oxide.

Abstract: The present invention relates to an apparatus for removing volatile impurities such as mercury and selenium from a weak acid solution resulting from scrubbing gases created in the production of sulfuric acid by roasting of sulfide concentrates. The apparatus comprises a calcine filtering unit for removing calcine from the weak acid solution, a sodium sulfide mixing unit for precipitating mercury from the weak acid solution, a sodium dithionite mixing unit for precipitating selenium from the weak acid solution, and a mercury-selenium filtering unit for filtering the precipitated mercury and selenium from the weak acid solution. The present invention further relates to a treatment plant utilizing such an apparatus, a process for removing volatile impurities from a weak acid solution, and a selenium cake obtained by utilizing the resent invention.

Abstract: Mercury salt-containing discharge effluents such as from B-5 fixatives and PVA fixatives are treated to remove mercury therefrom. The present method contemplates plates the addition of aluminum to the effluent to cause the precipitation of elemental mercury therefrom. The remaining effluent, after precipitation, can be decanted and post treated while recovering precipitated elemental mercury. The decanted effluent, once subjected to post treatment, by first rendering the effluent highly basic, is the neutralized. Neutralization causes the precipitation of sodium chloride. A water conditioner is then added thereto. Subsequently, the so-treated decanted effluent is then filtered through a filtering medium such as filter paper or the like. A second filtration step may then be carried out by passing the so-filtered effluent through a mixed bed or through a filter paper.

Abstract: A three-stage process for removing mercury contaminants from alcoholic alkali metal alkoxide solutions is provided, in which mercury is depleted in a first filtration through inert fibrous material, followed by a second filtration through pulverized coal, and then by concentration by distillation, to preferably provide a mercury content below 0.1 ppm.

Abstract: A method to remove heavy metals concentrations in water down to very low levels is described. The method calls for the addition of a soluble sulfide to the water. This is followed adding a soluble iron reagent such as ferrous sulfate or ferrous chloride. The water is aerated. As an alternative to aeration, the pH of the water can be increased. Finally, the solids generated from the above steps are separated from the water. This method has been shown to remove heavy metals, particularly copper and zinc, from actual industrial wastewater to very low concentrations, i.e., below about 100 ppb. Furthermore, the treated water is free of sulfide. The byproduct sludge comprises iron sulfide, iron oxides, iron hydroxides, and the heavy metal sulfides.

Abstract: A process is disclosed which involves removing hydrocarbons, arsenic and mercury from wastewater produced in oil and gas fields. An oxidant, ferric ions, and flocculent are sequentially added to the wastewater to form a removable sludge containing the arsenic, hydrocarbon, and mercury contaminants. The Oxidation-Reduction Potential of the wastewater is controlled by oxidant addition to allow the required arsenic oxidation to occur while maintaining the mercury in elemental form. The process requires relatively short residence times between chemical additions and provides for large wastewater throughputs. The cleaned wastewater is suitable for discharge to the environment.

Abstract: Municipal solid waste is classified as to density as well as size in a perforated inclined trommel through which a gas stream is flowed inwardly through the perforations and downwardly to entrain aid remove paper and plastics through the lower end. Ferrous and non-ferrous metals are removed from the residue which is digested anaerobically in two stages with an intermediate steam explosion treatment to expose cellulose fibers coated with lignin. Mercury may be removed as a vapor phase in an initial stage of the steam heating and condensed and collected. An aqueous phase of the anaerobic digestate may be treated to remove heavy metals and may be discarded or reused to slurry solid phase incoming to a digester. The solids phase of the anaerobic digestate may be acidified to solubilize heavy metals which are recovered by electrodeposition from the solution. The depleted residue can be neutralized and disposed of.

Abstract: Aluminum particles are reacted with heavy metal ions in a first acidic aqueous solution to form heavy metallic particles that are suitable for recycling and reuse when recovered from the first aqueous solution. The first residual aqueous solution may also contains ferrous ions obtained by acid redissolving a co-precipitated heavy metal hydroxide and ferrous hydroxide sludge that is produced in the treatment of a dilute chelated heavy metal solution. The first residual aqueous solution with heavy metals substantially removed is recycled and reused as the ferrous reagent for treating said dilute chelated heavy metal bearing solution. The process disclosed herein is useful for treating both dilute and concentrated wastes and wastewaters generated by industries such as metal plating and metal etching and printed circuit board fabrication.

Abstract: The invention relates to a method for separating metals present in a solution using chitosane. According to the present invention, chitosane in modified physical form is used which allows faster, more extensive fixation of the metals present in a solution. This purpose is achieved using a method in which the chitosane used is a lyophilizate of chitosane, in particular a lyophilizate of chitosane salt.

Abstract: A process of selectively separating a target metal contained in a solid matrix from the solid matrix by contacting a solid matrix containing a target metal with an aqueous solution including a water-soluble polymer adapted for complexation with the target metal for sufficient time whereby a water-soluble polymer-target metal complex is formed, and, separating the solution including the water-soluble polymer-target metal complex from the solid matrix is disclosed.

Abstract: A method for treating a quantity of soil contaminated with lead, copper or mercury includes mixing the contaminated soil with an acid, chloride solution, to dissolve the contaminants in the chloride solution. Soil, essentially free of the contaminants, is separated from contaminant-containing chloride solution. Contaminants are precipitated from the contaminant-containing chloride solution by addition of one or more sulfides. Precipitated contaminants are separated from the remaining solution. The remaining solution may treated by adding chloride, acid, ORP adjusting agents and used to treat an additional quantity of soil.

Abstract: A process for the recovery of mercury from mercury-containing caustic sludge, generated from a mercury cell, chlor-alkali plant, wherein mercury is removed from the caustic sludge by treatment in a hydraulic mineral separator. The process provides a ready method for removal of mercury from caustic sludge which can allow recovery of the mercury for re-use. Alternatively, the process provides a smaller volume of mercury-contaminated material to be treated and/or land-filled.

Abstract: An activated carbon based adsorbent carrying an acid is provided for eliminating mercury or mercury compounds contained in hydrocarbons. Preferably the activated carbon base is provided with more than 80 ml/g micropore volume having radii less than 8 angstroms. Preferably the acid carried on the activated carbon is hydrochloric acid, sulfuric acid, or phosphoric acid. Hydrochloric acid is most preferred. The active carbon base is preferably manufactured by activating a carbonaceous material in an atmosphere comprising less than 30 vol. % water vapor. The adsorbent can be used to eliminate mercury or mercury compounds contained in hydrocarbons by contacting the adsorbent with the hydrocarbons in liquid phase. Particular hydrocarbons include naphtha and intermediates of oil products or petrochemical products. Minimal amounts of carried acid are desorbed from the adsorbent to the hydrocarbons.

Abstract: The metal oxide media includes oxides and hydroxides of iron, and other metals. The material is derived from basic-oxygen steel-making process, and includes a high calcium content. The oxide surfaces facilitate the adsorption of phosphorus, and the increased pH facilitates the precipitation of calcium and other phosphates. The oxides are a catalyst for converting organic phosphorus to inorganic form. Limestone may be added to the oxides, to ensure a long-term source of calcium, and to maintain high pH for long periods.

Abstract: A method for removing pollutants from water, according to the preferred embodiment of the present invention, comprises the steps of providing algal spores for seeding, providing a source of water for flowing through a floway, and the water contains a quantity of pollutants and has a pH on entry into said floway, providing a growing surface in the floway upon which the algal spores form an attachment, subjecting the algal spores in the floway to operating conditions resulting in the formation of an algal turf in which the algae has cell walls on its surface, adjusting the floway operating conditions such that a predetermined pollutant precipitates onto and/or into the algal cell walls but not into the water, and harvesting a portion of the algal turf including the cell walls onto and/or into which the pollutants have precipitated.

Abstract: A method for removing heavy metals and halogenated hydrocarbons from contaminated groundwaters is provided. The method provides utilizing a treatment solution comprising a soluble source of organic carbon, ferrous iron, and sulfate. Additionally, the treatment solution may comprise sulfate reducing bacteria as well as nutrients for bacterial metabolism. The treatment is designed to stimulate the growth of naturally occurring sulfate reducing bacteria such that the metals are coprecipitated in iron sulfide and the hydrocarbons are reduced to innocuous byproducts.

Abstract: Municipal solid waste is classified as to density as well as size in a perforated inclined trommel through which a gas stream is flowed inwardly through the perforations and downwardly to entrain and remove paper and plastics through the lower end. Ferrous and non-ferrous metals are removed from the residue which is digested anaerobically in two stages with an intermediate steam explosion treatment to expose cellulose fibers coated with lignin. Mercury is removed as a vapor phase in an initial stage of the steam heating and is condensed and collected. The solids phase of the anaerobic digestate is acidified to solubilize heavy metals which are recovered by electrodeposition from the solution. The depleted residue is neutralized and disposed of.

Abstract: The invention relates to the use of barium sulphide or strontium sulphide for the removal of heavy metals in industrial acidic solutions.The invention is applicable to the purification of contaminated acids, in particular of spent battery acid, or of industrial solutions of titanyl sulphate.

Abstract: The invention relates to a water purification composition including silver metal and a second metal. The second metal is relatively reducing and helps control the overall silver cation concentration in solution. The composition effectively disinfects and removes toxic metal ions from water.

Abstract: Adsorbent alumina particulates which comprise coagulated droplets, extrudates or crushed alumina particles having a volume of pores with a diameter greater than 80 .ANG. of at least 0.15 cm.sup.3 /g and a particle size of less than 4 mm are well suited for adsorbing chelated organometallic compound values thereon, in particular from a medium of polymerization comprising same.

Abstract: Activated carbon is prepared specially by activating carbonaceous material in a circumstance comprising water vapor less than 15% on volume basis and providing thus treated activated carbon carries alkaline or alkaline earth metal sulfide in it. Thus prepared activated carbon or that carrying these compound provides for method of eliminating mercury and its compounds from liquid hydrocarbons substantially completely contained at a slight amount in it. Liquid hydrocarbons containing mercury or sulfur will harm catalysts which are often applied during process for such intermediates of petroleum products and petrochemical products. Thus the present method is advantageous to processing of such oil intermediates.

Abstract: Disclosed is a process for disinfecting water which provides a visual indication after the disinfection is complete. First, the water to be disinfected is generally simultaneously intermixed with at least three items. The items are: (1) a disinfectant which is adapted to render harmless substantially all pathogens present in the water upon the disinfectant being intermixed with the water for a time period T.sub.k ; (2) a colorant; and (3) a material which can remove substantially all of the disinfectant and colorant from the water over a time period T.sub.r, where T.sub.r is greater than T.sub.k. Secondly, the water, disinfectant, colorant and the removing material are allowed to remain intermixed for a time period of T.sub.r or greater. At the end of the time period T.sub.r, substantially all pathogens in the water will be rendered harmless, substantially all of the disinfectant will be removed from the water and substantially all of the colorant will be removed from the water.

Abstract: The present invention is a method to remove metals from solutions by precipitating the metals and adding cellulosic fiber to the solution. The precipitates attach to the cellulosic fibers to form products. The products may be removed from the solution by gravity separation techniques or by filtration. The removed products may be dewatered and incinerated. The method provides a simple and effective technique for removing low concentrations of metals from high volume solution streams.

Abstract: Heavy metal ions react with iron particles in acidic aqueous solution to form heavy metallic particles that are suitable for recycling and reuse when recovered from the aqueous solution. Chelating agents that are present are deactivated by bonding to ferrous ions produced from the iron particles. An alkali metal hydroxide is utilized to precipitate remaining heavy metal ions including ferrous and ferric ions which are recycled to the acidic aqueous solution.

Abstract: A process for the removal of species containing metallic ions from effluents by yeast cell walls. The yeasts used are selected from Saccharomyces cerevisae, Saccharomyces uvarum and Saccharomyces lipolytica. According to the process, the washed yeast cell walls are first treated by a water soluble aldehyde and after sorbing the metallic ions, the yeast cell walls may regenerated by a mineral acid or a chelate solution such as ethylene-diamine tetraacetic acid, releasing the sorbed metal ions. According to a preferred embodiment, water containing acetone or alcohol is used for washing the yeast cell walls. The sorption by the yeast cell walls is carried out at a pH in the range of 1 to 13 and preferably in the range of 4 to 7. The most preferred aldehyde is selected from formaldehyde and glutaraldehyde or any mixture thereof. The metal sorption process may be carried out batchwise or continuously. In the continuous process, the yeast cell walls are immobilized on porous glass, purified sand or polymers.

Abstract: The present invention is a method to remove metals from solutions by precipitating the metals and adding cellulosic fiber to the solution. The precipitates attach to the cellulosic fibers to form products. The products may be removed from the solution by gravity separation techniques or by filtration. The removed products may be dewatered and incinerated. The method provides a simple and effective technique for removing low concentrations of metals from high volume solution streams.

Abstract: Composite articles are useful for separating mercury from fluids. The composite articles can be porous supports comprising an inert substrate having immobilized thereon finely divided gold optionally in combination with a tin salt coating. The porous support can be a particulate or porous fibrous webs. Alternatively, the composite articles can comprise a porous fibrous membrane having enmeshed therein the aforementioned porous supports which can be in particulate or fibrous forms. The method for separating elemental, ionic, or organic mercury in fluids comprises the step of contacting and passing a fluid containing mercury through a support comprising a porous, high surface area, inert substrate on which is immobilized finely divided elemental gold at a controlled rate for a time sufficient for the mercury to sorb to the elemental gold and to provide an immobilized gold-mercury amalgam on the support. If a tin salt also is immobilized on the inert substrate, mercury-tin salt can also be formed.

Abstract: A process for removing dissolved oils and greases from an aqueous solution which also may contain dissolved heavy metals is provided wherein the aqueous solution is mixed with a source of ferrous ion and dithionite ion in a first step at acidic pH to reduce and permit removal of solid heavy metal, is present and to separate oils and greases from the aqueous solution. Solution from the first step if reacted in a second step with hydroxide slurries obtained from third and fourth steps. A second step solution from the second step is reacted in a third step with an alkali composition and a third solution. Optionally, the third solution is reacted with a chelating agent for iron and an oxidizer in a fourth step. A solution of chelated iron from the fourth step, when practical is disposed of. Oils and greases are recovered from the first step such as by skimming.

Abstract: Carbonaceous pyropolymers possessing recurring units containing at least carbon and hydrogen atoms on their surface are effective in removing from solution metal cations having a standard reduction potential to their zerovalent state of greater than -0.2 volts. Their mode of action appears to be via reduction of the metal to the zerovalent state which then is deposited on the pyropolymer surface.

Abstract: Heavy metals are separated from aqueous media containing the same by contacting the said medium with finely divided iron oxide (Fe.sub.3 O.sub.4) and finely divided ferrous sulphide, maintaining said contact until at least a substantial proportion of said heavy metal has become bound to said iron oxide and ferrous sulphide, and then separating the iron oxide and ferrous sulphide having heavy metal bound thereto from the aqueous medium.

Abstract: Method for removal of organic and inorganic mercury contaminants from a biological vaccine production facility.

Abstract: A method for reducing reducible metals comprising combining one or more reducible metals with an elemental metal, and then with a reducing agent to form a reduced metal. The mixture may then be stabilized and recovered.

Abstract: A precipitating agent containing thioacetamide is described for the precipitating of heavy metals from flue gases and waste waters, it containing thioacetamide (C.sub.2 H.sub.5 SN) in a 1-20% aqueous solution, which, in addition, contains a buffer substance in order to prevent hydrolyric spontaneous decomposition, the solution having a pH of between 5.5 and 9.0.

Abstract: A process for the removal of metal ions from solution and means for effecting such removal are described. The process is based on the hydroponic growth of sunflowers, terrestrial turfgrasses and/or members of the family Brassicaceae in solutions containing one or more metal ions. Metal ions can be efficiently removed from solutions by passing these solutions through the root biomass of these terrestrial plants. Columns containing the root biomass are also part of the invention.

Abstract: A method for eliminating mercury from mercury containing liquids by contacting the mercury-containing liquid with a plurality of fibers wherein the fibers making up the plurality of fibers have a coating of silver on the surface of the fibers, and a silver-coated fiber for use in the method are disclosed.

Abstract: Heavy metal ions react with ferrous dithionite in acidic aqueous solution. They are reduced to metallic particles that are suitable for recycling and reuse when recovered from the acidic water. Chelating agents that are present are deactivated by bonding to the ferrous ions. Ferrous dithionite, (FeS.sub.2 O.sub.4) is either generated in-situ or ferrous ions and dithionite ions can be provided by other methods. An alkali metal hydroxide is utilized to precipitate remaining heavy metal ions including ferrous and ferric ions.

Abstract: A process for the treatment of contaminants using metal scavenger is disclosed. The metal scavengers individually comprise a polyamine derivative and a polyethyleneimine derivative. The polyamine derivative is formed of a polyamine having a molecular weight not higher than 500 and contains, per molecule of the polyamine, at least one dithiocarboxyl group or a salt thereof as an N-substituting group substituted for an active hydrogen atom of the polyamine. The polyethyleneimine derivative is formed from a polyethyleneimine having an average molecular weight of at least 5,000 and contains, per molecule of the polyethyleneimine, at least one dithiocarboxyl group or a salt thereof as an N-substituting group substituted for an active hydrogen atom of the polyethyleneimine.

Abstract: A method is provided for removing metals from a fluid stream containing these metals. The method involves treating the fluid stream with a water soluble ethylene dichloride ammonia polymer having a molecular weight of from 500 to 100,000 that contains at least 5 mole percent of dithiocarbamate salt groups to form a complex with the metals. Then, the fluid stream is passed through a filtering device to remove the complexes from the fluid stream.

Abstract: Process for removing mercury from an organic medium which at least contains mercury and arsenic, wherein the organic medium is contacted with a solid polymeric substrate containing thiol groups bound to the polymeric substrate through aliphatic groups.