Methods for removing substances from aqueous solutions
First Claim
1. A method for removing one or more contaminants selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof from an aqueous solution comprising the contaminants and ferrous ions, the method comprising the steps of:
- (a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; and
(b) separating the amorphous precipitate from the solution so as to form an effluent solution having a substantially reduced contaminant concentration, wherein substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
step (a) includes the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a).
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Accused Products
Abstract
Methods are provided for removing contaminants from an aqueous solution to yield a less contaminated aqueous effluent. In one embodiment of the invention, the method comprises coprecipitating non-volatile contaminants (i.e., heavy metals, light metals, cyanide, phenolics, oil and grease, TSS, BOD, COD, and/or TOC) with a carrier precipitate which is formed in situ within the aqueous solution. In another embodiment of the invention, the method comprises partitioning volatile organic contaminants between a liquid phase and a gas phase. In yet a further embodiment, the above versions of the invention are simultaneously performed in the same reaction vessel.
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Citations
98 Claims
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1. A method for removing one or more contaminants selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof from an aqueous solution comprising the contaminants and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; and (b) separating the amorphous precipitate from the solution so as to form an effluent solution having a substantially reduced contaminant concentration, wherein substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
step (a) includes the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of removing contaminants selected from the group consisting of aluminum ions, beryllium ions, cyanide ions, and mixtures thereof from an aqueous solution comprising the contaminants and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; and (b) separating the amorphous precipitate from the solution so as to form an effluent solution having a substantially reduced contaminant concentration, wherein a portion of the contaminant concentration, wherein a portion of the contaminants are cyanide ions and a portion of the contaminants are selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof;
the molar ratio of the ferrous ions to the contaminants in the aqueous solution is about 1;
1 to about 10;
1;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
step (a) includes the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5;
the substantially completely amorphous precipitate comprises a substantial portion of the cyanide ions;
the effluent solution has a substantially reduced concentration of the cyanide ions; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a). - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A method for removing contaminants selected the group consisting of aluminum ions, beryllium ions, heavy metal ions, and mixtures thereof from an aqueous solution comprising the contaminants and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; and (b) separating the amorphous precipitate from the solution so as to form an effluent solution having a substantially reduced contaminant concentration, wherein a portion of the contaminants are at least one heavy metal ion and a portion of the contaminants are selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof;
the weight ratio of the ferrous ions to the contaminants in the aqueous solution is at least about 1;
1;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
step (a) includes the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5;
the substantially completely amorphous precipitate comprises a substantial portion of the heavy metal ions;
the effluent solution has a substantially reduced concentration of the heavy metal ions; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a). - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61)
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62. A method for removing contaminants selected from the group consisting of aluminum ions, beryllium ions, cyanide ions, heavy metal ions, and mixtures thereof from an aqueous solution comprising the contaminants and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; and (b) separating the amorphous precipitate from the solution so as to form an effluent solution having a substantially reduced contaminant concentration, wherein a portion of the contaminants are cyanide ions and at least one heavy metal ion and a portion of the contaminants are selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof;
the substantially completely amorphous precipitate comprises a substantial portion of the cyanide ions and the heavy metal ions;
the effluent solution has a substantially reduced concentration of the cyanide ions and the heavy metal ions;
the concentration of the ferrous ions in the aqueous solution is equal to about one to about ten times the molar concentration of the contaminants;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
step (a) includes the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a). - View Dependent Claims (63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77)
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78. A method for removing volatile organics and one or more contaminants selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof from an aqueous solution comprising the volatile organics, the contaminants, and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; (b) removing a substantial portion of the volatile organics by introducing a gas into the solution at a rate sufficient to achieve an average volumetric flux ratio of gas to water of at least about 20; and (c) separating the precipitate from the solution so as to form an effluent solution having a reduced contaminant and volatile organic concentration, wherein steps (a) and (b) are performed simultaneously and include the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a), and the concentration of the volatile organics in the effluent is less than about 20% of the concentration of the volatile organics in the aqueous solution prior to step (b). - View Dependent Claims (79, 80, 81, 82, 83)
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84. A method for removing volatile organics and contaminants selected from the group consisting of aluminum ions, beryllium ions, cyanide ions, and mixtures thereof from an aqueous solution comprising the volatile organics, the contaminants, and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; (b) removing a substantial portion of the volatile organics by introducing a gas into the solution at a rate sufficient to achieve an average volumetric flux ratio of gas to water of at least about 20; and (c) separating the precipitate from the solution so as to form an effluent solution having a reduced contaminant and volatile organic concentration, wherein a portion of the contaminants are cyanide ions and a portion of the contaminants are selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof;
the molar ratio of the ferrous ions to the contaminants in the aqueous solution is about 1;
1 to about 10;
1;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
steps (a) and (b) are performed simultaneously and include the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5;
the substantially completely amorphous precipitate comprises a substantial portion of the cyanide ions;
the effluent solution has a substantially reduced concentration of the cyanide ions; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a), and the concentration of the volatile organics in the effluent is less than about 20% of the concentration of the volatile organics in the aqueous solution prior to step (b). - View Dependent Claims (85, 86, 87, 88, 89)
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90. A method for removing volatile organics and contaminants selected from the group consisting of aluminum ions, beryllium ions, heavy metal ions, and mixtures thereof from an aqueous solution comprising the volatile organics, the contaminants, and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; (b) removing a substantial portion of the volatile organics by introducing a gas into the solution at a rate sufficient to achieve an average volumetric flux ratio of gas to water of at least about 20; and (c) separating the precipitate from the solution so as to form an effluent solution having a reduced contaminant and volatile organic concentration, wherein a portion of the contaminants are at least one heavy metal ion and a portion of the contaminants are selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof;
the molar ratio of the ferrous ions to the contaminants in the aqueous solution is at least about 1;
1;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
steps (a) and (b) are performed simultaneously and include the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5;
the substantially completely amorphous precipitate comprises a substantial portion of the heavy metal ions;
the effluent solution has a substantially reduced concentration of the heavy metal ions; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a), and the concentration of the volatile organics in the effluent is less than about 20% of the concentration of the volatile organics in the aqueous solution prior to step (b). - View Dependent Claims (91, 92, 93, 94)
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95. A method for removing volatile organics and contaminants selected from the group consisting of aluminum ions, beryllium ions, cyanide ions, heavy metal ions, and mixtures thereof from an aqueous solution comprising the volatile organics, the contaminants, and ferrous ions, the method comprising the steps of:
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(a) rapidly oxidizing substantially all the ferrous ions in the solution to ferric ions so as to rapidly form a substantially completely amorphous precipitate comprising a substantial portion of ferric hydroxide and a substantial portion of the contaminants; (b) removing a substantial portion of the volatile organics by introducing a gas into the solution at a rate sufficient to achieve an average volumetric flux ratio of gas to water of at least about 20; and (c) separating the precipitate from the solution so as to form an effluent solution having a reduced contaminant and volatile organic concentration, wherein a portion of the contaminants are cyanide ions and at least one heavy metal ion and a portion of the contaminants are selected from the group consisting of aluminum ions, beryllium ions, and mixtures thereof;
the substantially completely amorphous precipitate comprises a substantial portion of the cyanide ions and the heavy metal ions;
the effluent solution has a substantially reduced concentration of the cyanide ions and the heavy metal ions;
the concentration of the ferrous ions in the aqueous solution is equal to about one to abut ten times the molar concentration of the contaminants;
substantially all of the ferrous ions in the solution are oxidized to ferric ions within a period of less than about 30 minutes;
steps (a) and (b) are performed simultaneously and include the steps of introducing air into the solution at a rate of about 1 to about 10 l air per about 1,000 ppm ferrous ion present in the solution prior to step (a), and controlling the pH of the solution so that the pH of the solution is about 6 to about 9.5; and
the total concentration of the contaminants in the effluent solution is less than about 10% of the concentration of the contaminants in the aqueous solution prior to step (a), and the concentration of the volatile organics in the effluent is less than about 20% of the concentration of the volatile organics in the aqueous solution prior to step (b). - View Dependent Claims (96, 97, 98)
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Specification