Abstract: The invention is directed to a purifying device for sludge under water and a method for operating the same. The device includes a main fixing frame having an accommodating portion assess to the outside, a hollow liquid container in the accommodating portion, wherein the liquid container is provided with a liquid-flow hole and at least a backwash hole, multiple filters on the liquid container, and a pump connected to the liquid-flow hole at the liquid container through a liquid pipeline. The method includes steps: moving the liquid container having the filters to an area having a liquid to be filtered; leading the liquid to flow into the liquid container through the filters filtering out solid particles contained in the liquid; and leading a fluid to flow into the liquid container such that the filters can be backwashed accompanying with an external cleaning device if the filters are clogged.

Abstract: Arsenic is removed from water and other aqueous feeds by (1) treating the feed with a compound containing cerium in the +4 oxidation state, preferably cerium dioxide, to oxidize arsenic in the +3 oxidation state to arsenic in the +5 oxidation state and (2) removing the arsenic in the +5 oxidation state from the aqueous phase, normally by contacting the treated feed with alumina or other precipitating agent containing cations in the +3 oxidation state.

Abstract: Methods and apparatuses for depositing agents relatively deep within pores of bio-char. Bio-char is first produced in an airtight oven by heating biomass feedstock. The bio-char is then cooled and steam is diffused into the pores of the bio-char. The steam-laden bio-char is immersed in a liquid bath containing soluble agents that are to be deposited in the pores of the bio-char. The liquid bath cools the char to below the condensation temperature of the steam, whereupon the condensing steam generates a partial vacuum within the pores, drawing the liquid into the pores. The bio-char is then removed from the liquid bath and dried so that the liquid within the pores evaporates, leaving behind the soluble agent. Accordingly, the invention yields bio-char that has soluble agent embedded relatively deep within its pores.

Abstract: A method and an apparatus for treating selenium-containing wastewater, in which wastewater containing hexavalent selenium is subjected to reduction treatment, selenium can be effectively removed at a small amount of metal leached, and, preferably, sludge produced during treatment is white, thereby facilitating the disposal of the sludge. The selenium-containing wastewater is brought into contact with an alloy or a mixture of metallic titanium and a first metal other than metallic titanium to partially leach the first metal, thereby subjecting selenium in the wastewater to reduction treatment.

Abstract: A collection process for precipitated powder substance is mainly for storing toxic or highly radioactive powder or dust in air and involves collection operation in water or other liquid to collect powder insoluble to the liquid and heavier than the liquid. To be suitable for underwater operation, a powder precipitation bag is provided with an innovative powder collection can at its bottom. New powder collection can has a mesh filter in its bottom and two-stage structure. After completion of powder collection, the collection can is pulled up from the water and dried to reduce powder volume and form powder lumps. Then, the top half is removed, so the collection can is fully filled with powder lumps. The newly designed powder can increases storage efficiency and reduces waste of space by accommodating more powder lumps than traditional powder can. With the same total amount of powder, the new powder can enables fewer number of storage cans.

Abstract: A process and apparatus for removing elements is described herein.

Abstract: An apparatus for treating an aqueous solution containing arsenic. The apparatus comprises a container that includes a housing, an inlet located at a first end of the housing and an outlet located at a second end opposite the first end. An outer wall extends between the first and second ends and enclosing a fluid flow path between the inlet and the outlet and an arsenic fixing agent is disposed in the fluid flow path. The arsenic fixing agent can include an insoluble rare earth-containing compound, more specifically, a compound comprising one or more of cerium, lanthanum, or praseodymium. The inlet and the outlet are adapted to be closed during transport and storage. The container is adapted to be sealed for long term disposal after exposure to an aqueous solution containing arsenic.

Abstract: A method and a device for purifying water from contaminant trace species, especially arsenic, by co-precipitating trace species during oxidation and precipitation of iron compounds with subsequent separation. The co-precipitation is improved by contacting the water with an iron-containing material prior to oxidation to increase the iron content of the water. Arsenic and other trace species harmful to health may be removed from water effectively and in a simple manner, thus being able to comply with the more restrictive limits of arsenic in drinking water.

Abstract: Arsenic is a poisonous metalloid which, because of its hydroscopic nature, is primarily transported through water. Most plant species, including the nopal cactus, produce a sticky substance called mucilage. Mucilage swells in water but is insoluble and can precipitate ions, bacteria and particles from aqueous solutions. The invention includes a method of separating particulates and heavy metals such as arsenic (As) from drinking water using natural flocculants obtained from cactus mucilage. The extraction techniques and the methodology for using the cactus mucilage obtain higher As removal than conventional methods, like aluminum sulfate precipitation.

Abstract: The use of a sulfur-impregnated organoclay provides a mercury or arsenic removal media having increased reactivity, stability, and mercury removal ability. The Hg/As removal media described herein is prepared by impregnating an organophilic clay with elemental (free state) sulfur. Alternatively, the clay can be made organophilic by onium ion reaction prior to or simultaneously with impregnating the organoclay with sulfur.

Abstract: Systems and associated methods for treating contaminant-containing wastewater are provided. The systems generally include a reducing zone for reducing the oxidation-reduction potential of the water and a clean-up zone comprising zero valent iron for removing at least a portion of the contaminant from the contaminant-containing water. The systems are operable to remove one or more contaminants from the contaminant-containing water and are operable for extended durations without clogging due to the formation of iron hydroxides.

Abstract: A method for removing arsenite and arsenate from water is provided. The method comprises reacting the water with cupric oxide (CuO) particles for a predetermined time and filtering the reacted water. A system for removing arsenite and arsenate from liquids is also provided.

Abstract: A reducing water purification material having a reducing iron-based precipitate selected from green rust, iron ferrite, reducing iron hydroxide, and a mixture thereof. A wastewater treatment process having steps of adding a reducing iron compound to wastewater, leading the wastewater to which the reducing iron compound is added to a reaction tank and forming a precipitate, separating the formed precipitate by a solid-liquid separation to obtain a sludge, and alkalinizing all or a portion of the separated sludge to form an alkaline sludge followed by returning to the reaction tank, wherein in the precipitation step, the wastewater to which the reducing iron compound is added and the alkaline sludge are mixed and are allowed to react in a non-oxidizing atmosphere under alkaline condition to form a reducing iron compound precipitate as the precipitate, thereby incorporating contaminants in the precipitate to remove the contaminants from the wastewater.

Abstract: In one embodiment, a reactive filtration method includes continuously regenerating a reactive filter media while simultaneously filtering contaminants from fluid flowing through the filter media. In one embodiment, regenerating the reactive filter media comprises mixing metal granules with the filter media and agitating the mixture. In another embodiment, regenerating the reactive filter media comprises introducing a metal in the fluid flowing through the filter media and agitating the filter media. In one embodiment, a method for removing phosphorus, arsenic or a heavy metal from water includes introducing a metal salt reagent into the water at a molar ratio of 5:1 to 200:1 to the phosphorous or the arsenic in the water and passing the water through a bed of moving sand.

Abstract: Arsenic is removed from water and other aqueous feeds by (1) treating the feed with a compound containing cerium in the +4 oxidation state, preferably cerium dioxide, to oxidize arsenic in the +3 oxidation state to arsenic in the +5 oxidation state and (2) removing the arsenic in the +5 oxidation state from the aqueous phase, normally by contacting the treated feed with alumina or other precipitating agent containing cations in the +3 oxidation state.

Abstract: A porous grog with a body composition of water, clay and combustible material. Further, an earthenware water purification filter utilizing the porous grog in the body composition of the filter. Further, an earthenware filter utilizing silver chloride treatment for water disinfection is disclosed. A water purification system incorporating said filter, said water purification system capable of removing about 99% of all particles not less than 1.0 micron is size, and removing virtually 100% of fecal coliform indicators. In other embodiments, methods of disinfecting pottery toilet liners including various open surfaces using silver chloride treatment are disclosed.

Abstract: Systems and methods are provided for the removal and disposal of arsenic from an aqueous medium. The systems and methods include the removal of arsenic from a source by contact with either a chemically treated natural or synthetic zeolite, for example a ferric-loaded zeolite. The spent zeolite is disposed of at an appropriate arsenic disposal site. A system for monitoring and maintaining an arsenic removal/disposal system by an off-site provider is also disclosed.

Abstract: A method of removing arsenic and heavy metals from water using metal salt hydroxidegels is provided. The arsenic present in water is adsorbed onto the hydroxide-gels which can effectively be filtered through a diatomaceous earth (DE) filtration bed. The combination of DE mixed hydroxide-gels is also effective in removing arsenic from water and heavy metals from water.

Abstract: A process for removing selenium from a water stream, in particular a waste water stream, by: 1) the addition thereto of a ferric salt, followed by 2) the addition of a cupric salt and pH adjustment to a pH value in the range of from about 6.5 to about 8.0, thereby forming a copper-and-selenium-containing precipitate, and 3) removing the copper-and-selenium-containing precipitate to thereby form a treated water stream, is disclosed. The optional precipitation and removal of excess copper ions is also disclosed.

Abstract: A process for removing selenium from an aqueous stream using a supported sulfur material, and optionally the addition of an activating agent for enhanced removal of selenite, is disclosed.

Abstract: A process for removing selenium from an aqueous stream using a supported sulfur material, to convert selenocyanate to selenite, followed by removal of the selenite from the aqueous stream.

Abstract: Ruthenium compounds, either alone or in combination with other remediating compounds, can be used to oxidize, remove and sequester contaminants in water and soil or sediments.

Abstract: A lignocellulose-based anion-adsorbing medium (LAM) and process for making and using same for selectively removing phosphates and arsenic contaminants from aqueous solutions is disclosed. Making the LAM comprises (a) dissociating cations such as Fe and Al, from their counterions by adding a chemical compound containing said cations to water and acidifying; (b) pelletizing a lignocellulose; (c) adsorbing the cations to the lignocellulose by bringing the lignocellulose into contact with the solution of step (a) and incubating; and, (d) exposing the lignocellulose of step (c) to an alkaline fixing agent to replace hydrogens (H) of the hydroxyl groups of the lignocellulose with the adsorbed cations to produce the LAM with a positive charge. The LAM may be used to selectively and cost-effectively remove phosphate and arsenic contaminants from aqueous solutions by retaining them at the Fe or Al on the LAM.

Abstract: Arsenic is removed from water and other aqueous feeds by (1) treating the feed with a compound containing cerium in the +4 oxidation state, preferably cerium dioxide, to oxidize arsenic in the +3 oxidation state to arsenic in the +5 oxidation state and (2) removing the arsenic in the +5 oxidation state from the aqueous phase, normally by contacting the treated feed with alumina or other precipitating agent containing cations in the +3 oxidation state.

Abstract: A method for removing arsenic from water by contacting water with a strong base anion exchange resin comprising at least one metal ion or metal-containing ion whose arsenate salt has a Ksp no greater than 10?5, provided that the metal is not zirconium.

Abstract: The invention concerns a method for treating water for human consumption, so as to eliminate manganese and possibly other metals comprising steps which consist in: causing said water to pass at least over a bed of filtering material (3) consisting at least partly of manganese dioxide granules, said granules having a real density ranging between 3.5 and 4.5 and a hardness higher than 6 on the Mosh scale; regenerating, if necessary, said manganese dioxide, said regeneration being carried out mechanically.

Abstract: Methods for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical methods for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A method for continuous removal of arsenic from water is provided. Also provided is a method for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

Abstract: A process and medium for decontamination of water containing anionic species including arsenic and chromium, wherein compounds comprising divalent and trivalent metal oxides and sulfides are used to form surface complexes with contaminants under pH conditions within the range of potable water. In one embodiment natural and synthetic spinels and spinel-like materials are used as the sorbent substance.

Abstract: The present invention relates to methods for the rejuvenation of cupric oxide having adsorbed arsenic from arsenic contaminated water. The rejuvenated cupric oxide may be recycled to again react with and adsorb arsenic in arsenic contaminated water.

Abstract: An improved water decontamination process comprising contacting water containing anionic contaminants with an enhanced coagulant to form an enhanced floc, which more efficiently binds anionic species (e.g., arsenate, arsenite, chromate, fluoride, selenate, and borate, and combinations thereof) predominantly through the formation of surface complexes. The enhanced coagulant comprises a trivalent metal cation coagulant (e.g., ferric chloride or aluminum sulfate) mixed with a divalent metal cation modifier (e.g., copper sulfate or zinc sulfate).

Abstract: The invention is related to a method and an installation for removal of metal cations contained in a liquid, in which said liquid is brought into contact at a temperature greater than or equal to 60° C. with a chelating ion exchange resin formed from a polyazacycloalkane grafted on a solid support, said resin having been conditioned, previously to said contacting, at a pH of 4 to 6.

Abstract: A process and medium for decontamination of water containing anionic species including arsenic and chromium, wherein compounds comprising divalent and trivalent metal oxides and sulfides are used to form surface complexes with contaminants under pH conditions within the range of potable water. In one embodiment natural and synthetic spinels and spinel-like materials are used as the sorbent substance.

Abstract: A method of removing arsenic from water by using a reactor that is provided with a fluidized bed of carriers is disclosed. An arsenic-containing influent is mixed in the reactor with a sulfide aqueous solution or metallic salt aqueous solution at a predetermined pH, thereby resulting in formation of crystals of arsenic sulfides or arsenic acid metal salts. The arsenic contained in the influent is thus removed by crystallization. An effluent with a reduced arsenic content is discharged from the reactor. The carriers, on which the crystals are formed, are periodically removed from the reactor which is replenished with fresh carriers immediately after.

Abstract: The present invention relates to a process for the preparation of arsenic free water and an apparatus therefor. The present invention also relates to a porous ceramic useful for pressure filtration in order to produce arsenic free water. The present invention particularly relates to a process for preparing arsenic free (<10 ppb) water from arsenic contaminated ground water and apparatus therefor.

Abstract: A porous grog with a body composition of water, clay and combustible material. Further, an earthenware water purification filter utilizing the porous grog in the body composition of the filter. A water purification system incorporating said filter, said water purification system capable of removing about 99% of all particles not less than 1.0 micron is size.

Abstract: A method for oxidizing an inorganic species in an aqueous solution comprises the steps of: (i) supplying an oxidizable source of sulphur, and oxygen to the solution; and (ii) irradiating the solution with UV light such that both the inorganic and sulphur species are oxidized.

Abstract: Arsenic is removed from water and other aqueous feeds by (1) treating the feed with a compound containing cerium in the +4 oxidation state, preferably cerium dioxide, to oxidize arsenic in the +3 oxidation state to arsenic in the +5 oxidation state and (2) removing the arsenic in the +5 oxidation state from the aqueous phase, normally by contacting the treated feed with alumina or other precipitating agent containing cations in the +3 oxidation state.

Abstract: The present invention comprises a method and composition using akaganeite, an iron oxide, as an ion adsorption medium for the removal of arsenic from water and affixing it onto carrier media so that it can be used in filtration systems.

Abstract: An in situ process for treating ambient solid materials (e.g., soils, aquifer solids, sludges) by adding one or more divalent metal cations to the ambient solid material. The added divalent metal cations, such as Cu2+ or Zn2+, combine with metal oxide/hydroxides (e.g., ferric oxide/hydroxide or aluminum oxide/hydroxide) already present in the ambient solid material to form an effective sorbent material having a large number of positively-charged surface complexes that binds and immobilizes anionic contaminant species (e.g., arsenic or chromate). Divalent metal cations can be added, for example, by injecting an aqueous solution of CuSO4 into an aquifer contaminated with arsenic or chromate. Also, sludges can be stabilized against leaching of anionic contaminants through the addition of divalent metal cations. Also, an inexpensive sorbent material can be easily formed by mixing divalent metal cations with soil that has been removed from the ground.

Abstract: Systems for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical systems for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A system for continuous removal of arsenic from water is provided. Also provided is a system for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

Abstract: A method for removing dissolved arsenic from an aqueous medium comprising adding lime to the aqueous medium, and adding one or more sources of divalent metal ions other than calcium and magnesium to the aqueous medium, whereby dissolved arsenic in the aqueous medium is reduced to a lower level than possible if only the step of adding lime were performed. Also a composition of matter for removing dissolved arsenic from an aqueous medium comprising lime and one or more sources of divalent copper and/or zinc metal ions.

Abstract: The present invention is directed to an adsorbent for removing arsenic species from ground water and/or surface water systems. Such adsorbent removes both As(III) and As(V), thereby providing potable water. Also provided is a method and/or device (e.g., filter) for removing arsenic species from contaminated waters utilizing such adsorbent.

Abstract: A method of removing arsenic and fluoride from aqueous solutions in the same process is provided. Specifically, the pH of the aqueous solution is adjusted to a pH in the range of about 5 to 8. A combination of calcium salts, and ferric or aluminum salts are added to form insoluble arsenic and fluoride bearing solids. The solids are then removed from the aqueous solution.

Abstract: An apparatus for treatment of fluorine waste water has an introduction tank, a main treatment tank, a calcium hydroxide tank, a polychlorinated aluminum tank, a macromolecular flocculant tank, a settling tank, and a concentration tank. Fluorine waste water is introduced through the introduction tank into a lower part of the main treatment tank through a lower inlet pipe. Also, return sludge from the concentration tank and silicon sludge from a silicon waste water treatment system are introduced into an upper part of the main treatment tank. Thus, silicon recovered from silicon waste water is recycled for treatment of fluorine waste water. Also, unreacted chemicals, which have been loaded in the calcium hydroxide tank, polychlorinated aluminum tank, macromolecular flocculant tank, are recycled. The main treatment tank has no stirrer, and thus conserves electrical energy, but can neutralize the waste water.

Abstract: The methods and apparatus of embodiments of the present invention serve to precipitate dissolved inorganic arsenic from an aqueous solution. The pressurization/negative pressurization protocol promotes precipitation of dissolved inorganic arsenic. After pressurization/negative pressurization method is applied the newly created precipitates may be separated from the solution using known separation methods. Aeration of the solution prior to or during pressurization and addition of chemical oxidants and air injection prior to or during pressurization aid precipitation. The methods of embodiments of the present invention may be applied to batch-process and continuous, in-flow apparatus.

Abstract: Ascorbic acid or one of its isomers, such as erythorbic acid is added in sufficient quantities to a chlorite-containing solution to rid the solution of chlorite. Sufficient ascorbic acid is added to the chlorite-containing solution to convert the chlorite to chloride. Industrial processes employing this process are disclosed.

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: A method for the remediation of arsenic is presented, comprising providing an aqueous solution of inorganic arsenic species, and passing the solution of inorganic arsenic species over a substrate comprising zero valent iron under anaerobic conditions, thereby reducing the arsenic species and forming arsenic-metal co-precipitates. Preferably, the metal is iron in the form of iron filings, and a source of sulfate ions is also present, resulting in the precipitation of arseno-pyrites.

Abstract: A media is used to remove species from aqueous solutions, particularly in the treatment of water to enable it to be suitable for drinking. The media includes a material selected from the group consisting of zirconium hydroxide, titanium hydroxide, hafnium hydroxide and combinations thereof. A preferred form of the media is a layer having an aspect ratio of at least 1:1, more preferably, at least about 10:1. Removed from the water are species selected from the group consisting of arsenate, selenate, chromate, borate, perchlorate, fluoride and combinations thereof. In particular arsenite (As+3) containing species are also removed from water. Arsenite may be removed from water to levels not greater than 10 parts per billion with a single exposure to the media. The media is selective for certain species over others.

Abstract: In one embodiment, a reactive filtration method includes continuously regenerating a reactive filter media while simultaneously filtering contaminants from fluid flowing through the filter media. In one embodiment, regenerating the reactive filter media comprises mixing metal granules with the filter media and agitating the mixture. In another embodiment, regenerating the reactive filter media comprises introducing a metal in the fluid flowing through the filter media and agitating the filter media. In one embodiment, a method for removing phosphorus, arsenic or a heavy metal from water includes introducing a metal salt reagent into the water at a molar ratio of 5:1 to 200:1 to the phosphorous or the arsenic in the water and passing the water through a bed of moving sand.