Abstract:
A treatment method for stabilizing at least a portion of at least one heavy metal contained in a sodic fly ash to reduce leachability, wherein the sodic fly ash is provided by a process whereby a sodium-based sorbent is injected in a combustion flue gas to remove pollutants therefrom. The treatment method comprises contacting the sodic fly ash with at least one water-soluble source of silicate and at least one additive comprising calcium and/or magnesium. The material obtained from the contacting step is preferably dried. The additive may be selected from the group consisting of lime kiln dust, fine limestone, quicklime, hydrated lime, dolomitic lime, dolomite, selectively calcined dolomite, hydrated dolomite, magnesium hydroxide, magnesium carbonate, magnesium oxide, and any mixture thereof. A particularly preferred additive comprises lime kiln dust and/or dolomitic lime. The heavy metal to be stabilized in the sodic fly ash may comprise selenium and/or arsenic.
Abstract:
Hazardous compounds are chemically treated to remove various pollutants by subjecting the compounds (samples) to various process steps, including selecting specific solvents and using them, treating the sample at room temperature or below (30 DEG C or lower); separating fatty acids mixed with heavy metal and semi-metal compounds as well as the separation of organic substances (including halogenated compounds) added to heavy metals and semi-metals; and using sodium nitrite and sodium 1-naphthylamine-4-sulfonate in combination from specific solvents, thereby forming alkylsulfonic acid salt and alkyl sulfonium salt in the presence of sulfonic acid salt so as to fix organic substances mixed in the sample.
Abstract:
Methods for decontaminating toxic waste, particularly solid carrier materials, such as soil contaminated with a toxin, or solid mixed wastes are more efficiently decontaminated with solvated electrons by first extracting the toxin from the carrier with a nitrogenous base at elevated temperatures, followed by a temperature reduction before initiating chemical reduction of the toxin with solvated electrons. Pre-extraction of the toxin at elevated temperatures followed by temperature reduction minimizes competing side reactions, improves selectivity of solvated electrons for the toxin and improves the economics of the process with more efficient metal utilization. The process can be performed without separation of the toxin from the extraction vessel holding the solid carrier material. Alternatively, elevated temperatures can be used to perform one or more extractions of toxin with nitrogenous base followed by reduction with solvated electrons by performing the reaction in a separate reactor. The processes of the invention are useful in the destruction of virtually any chemically reducible hazardous substance.
Abstract:
Method for treating waste material contaminated with heavy metals so as to make it inert, characterized in that the material to be made inert, optionally at least in part neutralized, is subjected to the following operations, optionally under stirring: addition of a concentrate aqueous solution of orthophosphoric acid and of an alkaline or alkaline earth salt thereof in a molar ratio ranging from 1:5 to 5:1; optionally addition of water to give the homogeneous paste thus obtained a sufficient moisture content; addition of calcium hydroxide and/or calcium oxide; the resulting homogeneous paste being placed in the open air to help it dry out. The material thus obtained is fit to be disposed according to local environmental legislation.
Abstract:
The present invention relates to a method of producing an article suitable for use as a bioflocculant or a biosorbent for waste material and heavy metal removal. The method preferably comprises the steps of growing cells of a marine filamentous bacterium in a culture medium to achieve a log phase of bacteria growth (100); harvesting by way of separating the said cells of marine filamentous bacterium from the culture medium (200), wherein the step of harvesting includes centrifugation; and fixing the harvested cells of marine filamentous bacterium by subjecting the same to treatment with formaldehyde (300), wherein the said article comprises the fixed cells of marine filamentous bacterium.
Abstract:
A treatment method for reducing the leachability of selenium contained in a sodic fly ash which is provided by a combustion process when a sodium-based sorbent comes in contact with a flue gas generated by combustion to remove at least a portion of pollutants contained in the flue gas. The method comprises: (a) contacting the sodic fly ash with at least one additive in the presence of water; and (b) drying the material (preferably a paste) from step (a) to form a dried matter. The additive may comprise at least one strontium-containing compound, at least one barium-containing compound, dolomite, a dolomite derivative such as calcined or hydrated dolomite, at least one silicate-containing compound, or any combinations of two or more thereof. A particularly suitable additive may comprise strontium chloride, strontium hydroxide, pulverized dolomitic lime, sodium silicate, or any combinations of two or more thereof.
Abstract:
The method of the present invention detoxifies spent aluminum potliners to remove hazardous cyanides, fluorides, and polynuclear aromatics by reacting crushed potliners with a CaC12/HC1 leach mill solution in the presence of iron. The method produces a solid waste suitable for landfill disposal and a recyclable reaction liquor. The reaction to destroy the polynuclear aromatics preferably occurs at a pH of no more than about 0.2, at about 120 DEG C and 80 psig following destruction of the cyanides and converting of the fluorides to florspar in an initial oxidation at a lower temperature, lower pressure, and higher pH.
Abstract:
A method is described for preparing a product adapted for stimulation and enhancement of processes of reduction, transformation and metabolization of polluting substances that are present in soils and/or waters, the method comprising the following steps: a first step comprising: - preparing a totally natural mineral substance based on Magnesium Potassium Sulphate, "activating" said mineral substance by mixing it for a time of 3' 23", with a tolerance of plus-minus 10 seconds; a second step comprising: making an organic -base product obtained by burying bovine manure inserted in cow horns into weakly calcareous soil (pH 7.5-8.0) for a period lasting from the autumn to the following spring; - thereafter, dynamizing said organic -base product by mixing a part thereof into 99 parts of distilled water, thereby obtaining a liquid substance; said dynamization comprising a first active phase of succussions for 60 seconds, followed by a pause of 80 seconds, in turn followed by a second active phase of succussions for additional 60 seconds, said liquid substance is then diluted again with distilled water in a proportion of 1 to 99 and then further dynamized with said succussions followed by pauses, repeated 5 more times; a third step comprising: combining the product obtained in the first step with the product obtained in the second step, in a proportion of 1 ml of product of the second step for 1 kg of product of the first step; "activating" said combination by mixing it for a period of 5' 25" (with a tolerance of plus-minus 10 seconds), thereby obtaining said product adapted for stimulation and enhancement.