Abstract: A process for the removal of soluble polyvalent metal impurities from aqueous streams, the polyvalent metal selected from groups IIIA, IIIB, IVA, IVB, VA, VB, VIB, VIIB, and VIII in the periodic table of elements, is disclosed. The process comprises, in order:(1) dissolving (a) chitosan or a water soluble salt thereof and (b) a halogenating agent capable of converting chitosan to an N-halochitosan in an aqueous stream that (i) contains said polyvalent metal impurity as a cationic or complex anionic moiety and (ii) is at a pH of 2 to 5.5, wherein an effective amount of N-halochitosan is formed in said aqueous stream to remove said polyvalent metal impurity;(2) raising the pH of the aqueous stream to a pH greater than 6, the pH being sufficiently high to form an insoluble product containing the polyvalent metal impurity and said N-halochitosan; and(3) separating the insoluble product from the aqueous stream.

Abstract: Solutions such as for example groundwater, drinking water, extracting solutions and effluents contaminated with metals, radioactive species and organics, singly or in combination, are treated by first removing undesirable oxidizing agents from the contaminated solution. Then the contaminated solution is separately treated with aqueous solutions of ferrous sulfate and hydroxide, which precipitate substantially all of the contaminants. Next, the precipitate is treated with a flocculant and/or a coagulant to form an easily dewaterable and separable solid. The solid contaminants are readily removed from the cleansed solution. The process utilizes a novel combination of steps which maximizes contaminant removal, minimizes waste volume, and produces a recyclable solution and a manageable waste stream. The preferred hydroxide solutions are sodium hydroxide, calcium hydroxide, and ammonium hydroxide.

Abstract: An adsorption system, such as a composite drier-bed, having at least two distinct adsorption regions for simultaneously drying and removing metallic/inorganic and organic forms of mercury from a fluid including a container having an entrance area and an exit area; a distinct first region located within said container and proximal to said entrance area of a porous substrate having elemental silver associated therewith; and a distinct second region adjacent thereto of a porous substrate having elemental gold associated therewith. The first region substantially removes water and metallic forms of mercury and the second region substantially removes organic forms of mercury and residual water from said fluid. A method of removing both metallic and organic mercury simultaneously with water as well as a means for regenerating the drier-bed is also disclosed.

Abstract: A process for selectively recovering dissolved heavy metals from a solution is disclosed that involves selectively reacting a xanthate with such dissolved heavy metals. Selective reaction of a xanthate with selected dissolved heavy metals is accomplished by conducting the reaction under conditions such that only some of the heavy metals react with the xanthate, to the exclusion of reaction with other dissolved heavy metals. Selectivity of the reaction is particularly influenced by the pH at which the reaction occurs. Typically, the reaction should occur at a pH below about 4.0. Xanthates, once reacted, can be separated from the heavy metal xanthate reaction product and recycled for use within the process. Purified heavy metal product can be produced if desired.

Abstract: Metals that form sparingly soluble sulfides are removable from industrial wastewaters by adding a precipitant comprising a suspension obtained by mixing sulfur, an iron(II) salt, water and a base, adjusting the wastewater pH to >4, and separating off the resulting sulfidic precipitate in a conventional manner.

Abstract: A process for removing dissolved heavy metal from an aqueous solution is provided where 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 the heavy metal. Solution from the first step is reacted in a second step with hydroxide slurrys obtained from third and fourth steps. A second solution from the second step is reacted in a third step with an alkali composition and a third solution. 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 is disposed of.

Abstract: A method of recovering contaminants from suspension or solution in a liquor comprises the steps of forming a foam of the liquor, displacing said foam onto a drainage device to dry said foam and separate the liquor said contaminants being retained in the dried foam and the drained liquor being reduced in contaminant content.

Abstract: A water purifying system including two or more stages for removing organic and inorganic contaminants from source water. The system may be configured such that water is first passed through a biocidal resin, and then through a granular metal alloy and an activated carbon filter to remove iodides released into the water by the biocidal resin. The granular metal alloy may be agitated by turbulent motion as the water treated.

Abstract: Methods are disclosed for removing oil and metal ions from oily wastewaters. Polymeric tannin amine compounds are added to the oily wastewater to demulsify the oil, and flocculate the metal ions.

Abstract: Mercury is often removed as an impurity from process fluid streams by adsorption in fixed beds using any of several well-known adsorbents having the ability to selectively adsorb mercury. It is also common to reintroduce this sequestered mercury into the environment by means of the spent gas used to periodically regenerate the fixed beds. A solution to this problem is provided by the present invention in which the mercury is removed from the process stream using a large non-regenerated adsorption bed in combination with a periodically regenerated secondary adsorption bed, the mercury content of the latter being transferred to the former during the regeneration procedure.

Abstract: A process for producing a natural gas condensate having a reduced amount of mercury from a mercury-containing natural gas wellstream, wherein the wellstream is separated into gaseous and liquid fractions. The treatment of the gaseous fraction includes treatment with a carbonate solution which, upon regeneration, yields an acid gas. A portion of the acid gas is mixed with the liquid fraction, the mixture is then filtered, passed over a substance capable of adsorbing hydrogen sulfide, and separated into a stream comprising a natural gas condensate and at least one other stream comprising lower molecular weight hydrocarbons and/or other gases.

Abstract: In a method of and apparatus for recovering mercury from drainage, mercury-containing waste water is fed into a first treating tank where the waste water is heated together with a metal having a stronger ionizing tendency than mercury, to reduce mercury ions in the waste water and free the mercury ions as metallic mercury. The solution under treatment is then transferred to a second treating tank where the solution is alkalinized, and mercury ions remaining in the solution is reduced by means of a water soluble metallic salt having a stronger ionizing tendency than mercury, to free the mercury ions as metallic mercury. Mercury vapor containing gases generating from the first and second treating tanks are cooled in a cooling device, and condensed and liquefied mercury is collected in a gas-liquid separator. Exhaust gas generating from the gas-liquid separator is fed into the solution under treatment in the second treating tank.

Abstract: Thimerosal is removed from aqueous effluent streams from vaccine production to provide an invironmentally-acceptable effluent stream. The thimerosal first is converted to ionic form by chlorination, the resulting solution is dechlorinated to remove dissolved unreacted chlorine, and then the ionic mercury is removed by ion-exchange employing thiol groups.

Abstract: A process for producing a natural gas condensate having a reduced amount of mercury from a mercury-containing natural gas wellstream, wherein the wellstream is first separated into gaseous and liquid fractions. The treatment of the gaseous fraction includes treatment with a carbonate solution which, upon regeneration, yields an acid gas which is mixed with the liquid fraction. The mixture is then separated from gaseous components and filtered.

Abstract: The process relates to on-line rejuvenation of adsorbent beds which are used for removing mercury from mercury contaminated feeds.

Abstract: Disclosed is a method for treating in a continuous manner an aqueous solution containing ions of a given type in order to remove these ions from the solution. According to this method, the aqueous solution containing the ions to be removed is first neutralized if it is acidic. Then, it is contacted with a metal salt which is sparingly soluble in water and has a very strong affinity to react with the ions to be removed to form therewith another salt which is insoluble in water, for a period of time sufficient to allow this other salt to be formed and precipitate. This method is very efficient and can be used, by way of example, for removing chromium ions from an industrial waste water, using barium carbonate as sparingly soluble salt.

Abstract: In a method for removing mercury from a wastestream to produce an environmentally acceptable discharge, the wastestream is contacted with an effective amount of an adsorbent composition which includes a metal compound capable of forming an amalgam and/or a sulfide with mercury and a support. After contact, the treated wastewater is discharged amd the adsorbent composition is regenerated. A method for making the adsorbents is also provided.

Abstract: A method is disclosed for the quantitative removal and concentration of desired transition metal ions from a source solution which may contain larger concentrations of other metal and H.sup.+ ions. The method comprises bringing the source solution into contact with a compound comprising a pyridine containing ligand covalently bonded through an organic spacer silicon grouping to a solid inorganic support. The pyridine portion(s) of the compound has an affinity for the desired metal ions to form a complex thereby removing the desired metal ions from the source solution. The desired metal ions are removed from the compound by contacting the compound with a much smaller volume of a receiving solution having a greater affinity for the desired metal ions than does the pyridine ligand portion of the compound. The concentrated metal ions thus removed may be recovered by known methods.

Abstract: A process for the removal of heavy metals such as lead, cadmium, zinc, chromium, arsenic and mercury from aqueous solutions containing one or more of said metals as well as competing ions such as calcium and/or magnesium by contacting said aqueous solution with amorphous titanium or tin silicates is disclosed. Said amorphous titanium and tin silicates are characterized by a silicon-to-titanium or tin molar ratio of from 1:4 to 1.9:1 and a cumulative desorption pore volume ranging from about 0.03 to about 0.25 cubic centimeters per gram.

Abstract: In the treatment of solid residues containing heavy metals from combustion plants, the heavy-metal compounds dissolved after washing-out and subsequently precipitated are separated from the solvent, usually water or slightly acid aqueous solutions by cross-current diaphragm filtration. The sludge obtained during filtration and comprising precipitated insoluble heavy-metal compounds is dewatered together with the remaining solid residues and made suitable for dumping, e.g. by using binders. The cross-current diaphragm filter improves the washing of heavy metals out of the washing or waste water, and the method and the associated plant are simplified by the joint processing of the sludges containing solids.

Abstract: A liquid hydrocarbon such as a natural gas liquid generally contains a small amount of mercury in a state of elemental mercury, ionized mercury, ionizable mercury compounds, which are requested to be removed thoroughly. Further, organic mercury compounds are contained in some natural gas liquid and other liquid hydrocarbons depending on their district of production, and its removal is also necessary.Already known adsorbents can adsorb elemental mercury and organic mercury compounds in a liquid hydrocarbon, but they hardly adsorb ionizable mercury compounds and ionized mercury derived from the ionizable mercury compounds.According to the preesent invention which comprises contacting the liquid hydrocarbon with a sulfur compound represented by a general formula MM'S.sub.

Abstract: The effluent from mercury collected during the photochemical separation of the .sup.196 Hg isotope is often contaminated with particulate mercurous chloride, Hg.sub.2 Cl.sub.2. The use of mechanical filtering via thin glass tubes, ultrasonic rinsing with acetone (dimethyl ketone) and a specially designed cold trap have been found effective in removing the particulate (i.e., solid) Hg.sub.2 Cl.sub.2 contaminant. The present invention is particularly directed to such filtering.

Abstract: A process for the removal of heavy metals such as lead, cadmium, zinc, chromium, arsenic and mercury from aqueous solutions containing one or more of said metals as well as competing ions such as calcium and/or magnesium by contacting said aqueous solution with a crystalline molecular sieve having the X-ray diffraction patterns of ETS-10 or ETAS-10.

Abstract: A method of separating a heavy metal ion from an aqueous solution containing the heavy metal ion, comprising the step of bringing a chitosan derived from a chitosan-producing microorganism into contact with said aqueous solution. The chitosan used, which can be produced by a simple process, has good heavy metal ion adsorptivity; this method can effectively separate heavy metal ion from a solution containing it.

Abstract: A process for producing a natural gas condensate having a reduced amount of mercury from a mercury-containing natural gas wellstream, wherein the wellstream is separated into gaseous and liquid fractions. A portion of the gaseous fraction is mixed with the liquid fraction, the mixture is then filtered, passed over a substance capable of adsorbing hydrogen sulfide, and separated into a stream comprising a natural gas condensate and at least one other stream comprising lower molecular weight hydrocarbons and/or other gases.

Abstract: A process for producing a natural gas condensate having a reduced amount of mercury from a mercury-containing natural gas wellstream, wherein the wellstream is separated into gaseous and liquid fractions. A portion of the gaseous fraction is mixed with the liquid fraction, the mixture is then separated into a stream comprising a natural gas condensate and at least one other stream comprising lower hydrocarbons and/or other gases. The natural gas condensate stream is then filtered.

Abstract: A method for removing mercury from water or hydrocarbon condensate is provided. The mercury-containing liquid is sprayed into a stripper having a packing therein to facilitate its contact with a stripping gas such as air or natrual gas. The stripped product is drawn from the bottom of the stripper. The stripping gas which carries the mercury from the stripper is passed over an active adsorbent to remove the mercury. The cleaned gas may be used or recycled.

Abstract: A useful method for the recovery of heavy metal sulfides and alkali or alkaline earth metal salts of N-substituted dithiocarbamic acids from material containing heavy metal salts of N-substituted dithiocarbamic acids.

Abstract: The invention is concerned with a process for removing mercury from a non-polar organic medium like a liquid hydrocarbon mixture, most preferably a natural gas condensate, by contacting the medium to be treated with a solid adsorbent, preferably an ion-exchange resin, containing active thiol-groups. By this method it is possible to remove mercury from the treated medium in an amount of more than 97%.

Abstract: Liquid hydrocarbons such as natural gas liquid generally contain elementary mercury, ionized mercury and ionizable mercury compounds. All of them are requested to be removed. Further, organic mercury compounds are contained in some natural gas liquid and other liquid hydrocarbons depending on their district of production, and its removal is also necessary.It has been found that an adsorbent composition comprising multi-component metal sulfides supported on a carrier wherein one of metal component is molybdenum of 3-15 weight-% calculated as molybdenum metal in final product and another metal component is selected from the group consisting of cobalt and nickel, the atomic ratio of these to molybdenum being in the range of 0.05-0.9 can adsorb more amount of elemental mercury from hydrocarbons than the conventional adsorbents.

Abstract: Precipitation (conversion) of dissolved heavy metals in waste effluents is achieved with the addition and mixing of a solution of sodium polythiocarbonate with a solution containing dissolved heavy metals. The solution of sodium polythiocarbonate has been pH buffered to a pH of 12.5 or less in the manufacturing process. Precipitation of the dissolved heavy metals with the buffered sodium polythiocarbonate is complete by the formation of a stable, unleachable [as defined in 40 CFR 190.01, Part 261 Appendix II (Code of Federal Regulations)], extremely insoluble metallic polythiocarbonate particle.

Abstract: A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.

Abstract: A regenerable molecular sieve comprises 0.001-15% elemental silver or gold in or on zeolite A. The molecular sieve is capable of simultaneously removing mercury and water from a fluid. A method for impregenating zeolite A with elemental silver or gold comprising treating the zeolite A with a solution of a silver or gold salt of a carboxylic acid and heating the impregnated zeolite A at a temperature sufficient to decompose the salt is also provided. A method for simultaneously and repeatedly removing mercury and water from a hydrocarbon fluid by contacting the fluid with an effective amount of a molecular sieve comprising zeolite A and 0.001-15% elemental silver or gold and regenerating the zeolite A at elevated temperatures is also provided.

Abstract: Process for the removal of metals, in particular heavy metals and strontium, from waste water in the form of their sulfide by mixing the waste water with a water soluble sulfide. According to the invention the metal containing waste water is thoroughly mixed with the water soluble sulfide at a suitable pH in a reactor of the fluidized bed type, which is provided with an appropriate bed material, on which the metal sulfide crystallizes out, whereby the thus obtained bed material provided with crystalline metal sulfide is removed from and new bed material is added to the reactor from time to time. Usually as water soluble sulfide an alkali metal sulfide or alkali metal hydrogen sulfide or ammonium sulfide or FeS is used, whereas the use of sodium sulfide, sodium hydrogen sulfide, potassium sulfide or potassium hydrogen sulfide is preferred. According to the present process a.o. the following metals: Ni, Sr, Zn, Cu, Fe, Ag, Pb, Cd, Hg, Co, Mn, Te, Sn, In, Bi or Sb may be removed.

Abstract: A coal gasifier slag composition, and process utilizing a coal gasifier slag composition for the removal of a metal ion, or the ions of a plurality of metals, from an aqueous medium by contact of said coal gasifier slag composition with said aqueous medium. The coal gasifier slag, which is regenerable by contact with a dilute acid, is employed as a contact mass for the removal from an aqueous medium of a metal ion, or the ions of a plurality of metals, derived from Groups IB through VIIB, IIA through VA, and VIII of the Periodic Table of the Elements. The coal gasifier slag is useful for removing a metal ion, or the ions of a plurality of metals, from industrial waste water, groundwater, mine water and the like, or as a landfill, or as a protecting layer adjacent to or surrounding land fills, surface impoundments, tank farm beds and the like.

Abstract: A method for stabilizing a mercury-containing waste comprising adding elemental sulfur and cement kiln dust to the waste in amounts effective to reduce the amount of leachable mercury to an environmentally acceptable level.

Abstract: A process for reducing the concentration of ionic species of heavy metals in an aqueous waste solution by conversion to a corresponding elemental metal comprises contacting the waste solution containing ionic species of one or more heavy metals with a culture of Pseudomonas maltiphilia ATCC 53510 in the presence of an amount of nutrient medium sufficient to satisfy nutritional requirements of cells of the culture of Pseudomonas maltiphilia ATCC 53510. When the ionic species is other than Hg.sup.+ or Hg.sup.++, other species of Pseudomonas can be used.

Abstract: A process for removing metals from water including the steps of prefiltering solids from the water, adjusting the pH to between about 2 and 3, reducing the amount of dissolved oxygen in the water, increasing the pH to between about 6 and 8, adding water-soluble sulfide to precipitate insoluble sulfide- and hydroxide-forming metals, adding a flocculating agent, separating precipitate-containing floc, and postfiltering the resultant solution. The postfiltered solution may optionally be eluted through an ion exchange resin to remove residual metal ions.

Abstract: A method of treating a heavy metal and/or a radioactive metal-containing natural water or liquid such as a radioactive metal-containing wastewater stream, a potable water supply containing naturally-occuring radioactive elements, an oil containing one or more radioactive metals, or other nuclear metal-bearing liquid by contacting the radioactive heavy metal-containing liquid with a water-insoluble carboxylated cellulose-transition metal oxide mixture to separate the heavy metals from the liquid. The heavy metal and radioactive heavy metals precipitate from the liquid onto the cellulose material to form a radioactive metal-laden solid material. The radioactive metal-laden solid then is air-dried, calcined and/or admixed with a leach-resistant matrix, such as grout or asphalt, for suitable disposal.

Abstract: This invention relates to a process for reducing the concentration of heavy metal ions in an aqueous waste solution, comprising the steps of:(a) contacting the aqueous waste solution with a mixed culture of Citrobacter freundii and a dissimulatory sulfate reducer, in the presence of nutrient sufficient to satisfy the nutritional requirements of the mixed culture, for a time sufficient to produce sulfide ions from a sulfide-ion precursor in the aqueous waste solution or nutrient and to precipitate the heavy metal ions in the form of corresponding sulfides and(b) removing the thus-precipitated sulfides from the waste solution.

Abstract: The present invention relates to a method for treating lakes with selenium with the intention of lowering the mercury content of fish, and is characterized by supplying to the lake selenium in the form of a selenium salt incorporated in a carrier material capable of dispensing selenium to the surrounding water substantially continuously and in a controlled manner. The carrier material is preferably a rubber-based or silicon-based and biologically degradable material. There is preferably maintained an effective selenium level of beneath 10 .mu.g.

Abstract: Process for removing Sr and heavy metals from water in particular from waste water by throughly mixing it with a solution of an alkali metal carbonate and/or hydrogen carbonate in a reactor containing a fluidized bed of suitable bed material. The obtained heavy metal carbonate crystals crystallize onto said bed material and the obtained heavy metal carbonate crystals in granular form are removed from the reactor from time to time.The heavy metals which may be removed are Ni, Zn, Cu, Fe, Ag, Pb, Cd or Hg.

Abstract: A method for treating a radioactive metal-containing natural water or liquid such as a radioactive metal-containing wastewater stream, an oil containing one or more radioactive metals, or other nuclear metal-bearing liquid by contacting the radioactive heavy metal-containing liquid with a water-in-soluble carboxylated cellulose to separate the heavy metals from the liquid. The process has been found to be unexpectedly effective on radioactive wastewaters or any other liquid containing one or more radioactive heavy metal ions such as U, Ce, Sr, Ru, Ra, Np, Tc, as well as radioactive ions such as I.

Abstract: The present invention relates to a cyclic continuous process and composition for the removal of metal ions, particularly transition metal ions, from aqueous solutions a fluid stream containing the metal ions is contacted with an aqueous solution of a water soluble organic polymeric chelant. The metal is chelated by the chelant: The separation of water and low molecular weight products (molecular weight less than 500) is accomplished usually by dialysis or ultrafiltration. The metal ion is then released using dilute mineral acid and collected. The water-soluble chelant is then recycled. The metal ions chelated removed included iron, cobalt, copper, vanadium, cadmium, nickel, zinc, lead, and aluminum. A preferred chelant is one having a pendant pyridine group in conjunction with alkyl amine groups, e.g., --N(R)--CH.sub.2 --C.sub.5 H.sub.4 N, where R is alkyl.

Abstract: A heavy metal can be removed from waste water, in which the metal is contained as ions, by adding to the waste water a metal scavenger together with at least one of sodium monosulfide, sodium polysulfides and sodium hydrogensulfide to form a metal ion containing floc. The resulting floc is then removed from the waste water by filtration. The metal scavenger contains at least one carbodithio group and/or at least one carbodithioate salt group as N-substituents per molecule.

Abstract: A process for reducing the concentration of ionic species of heavy metals in an aqueous waste solution by conversion to a corresponding elemental metal comprises contacting the waste solution containing ionic species of one or more heavy metals with a culture of Pseudomonas maltophilia ATCC 53510 in the presence of an amount of nutrient medium sufficient to satisfy nutritional requirements of cells of the culture of Pseudomonas maltophilia ATCC 53510. When the ionic species is other than Hg.sup.+ or Hg.sup.++, other species of Pseudomonas can be used.

Abstract: A method of treating wastewater containing a contaminant selected from the group consisting of heavy metal cations, tars, oils and phenols or mixtures thereof, comprising mixing said wastewater with an effective amount of desulfurization slag, the composition of said slag including calcium oxide, calcium sulfide and iron oxides, causing deposition of said contaminant from the mixture, and separating the deposit from the supernatant liquid.

Abstract: A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

Abstract: An adsorbing agent and a method of preparation thereof is disclosed, which agent is capable of selectively adsorbing mercury from various mercury-containing gaseous or aqueous media at high rate of efficiency. The agent essentially comprises a porous material having a specific surface area in excess of 10 m.sup.2 /g. and a conjugated diolefin lower polymer deposited in a predetermined amount on the porous material.

Abstract: Mercury can be recovered from nitric acid-containing fluids by reacting the fluid with aluminum metal to produce mercury metal, and then quenching the reactivity of the nitric acid prior to nitration of the mercury metal.