System and Method for Treatment of Acidic Wastewater
First Claim
1. A method of removing contaminants from an influent wastewater stream, the method comprising:
- a. initially chemically adjusting a pH of the influent wastewater stream to less than about 3.5 or maintaining the pH of the influent stream at less than about 3.5;
b. after initially adjusting or maintaining the pH of the influent wastewater stream, directing the wastewater to a first reverse osmosis system and removing contaminants from the wastewater;
c. directing the wastewater from the first reverse osmosis system to a second reverse osmosis system and removing contaminants from the wastewater; and
d. adjusting the pH upwardly after the wastewater has been subjected to treatment in the first reverse osmosis system and prior to treatment in the second reverse osmosis system.
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Abstract
A method for removing contaminants from an influent wastewater stream includes initially chemically adjusting a pH of the influent wastewater stream to less than about 3.5 or maintaining the pH of the influent stream at less than about 3.5. After initially adjusting or maintaining the pH of the influent wastewater stream, the wastewater is directed to a first reverse osmosis system and contaminants are removed from the wastewater. The wastewater is then directed to a second reverse osmosis where additional contaminants are removed from the wastewater. After the wastewater has been subjected to treatment in the first reverse osmosis system and prior to treatment in the second reverse osmosis system, the pH of the wastewater is adjusted upwardly.
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Citations
20 Claims
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1. A method of removing contaminants from an influent wastewater stream, the method comprising:
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a. initially chemically adjusting a pH of the influent wastewater stream to less than about 3.5 or maintaining the pH of the influent stream at less than about 3.5; b. after initially adjusting or maintaining the pH of the influent wastewater stream, directing the wastewater to a first reverse osmosis system and removing contaminants from the wastewater; c. directing the wastewater from the first reverse osmosis system to a second reverse osmosis system and removing contaminants from the wastewater; and d. adjusting the pH upwardly after the wastewater has been subjected to treatment in the first reverse osmosis system and prior to treatment in the second reverse osmosis system. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of influent wastewater and removing fluorides and silica from the influent wastewater, the method comprising:
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a. inhibiting conditions in the influent wastewater that promote the formation of at least one of fluoride ions or silicate ions and promoting conditions in the wastewater that favor the formation of hydrofluorosilicic acid by initially chemically adjusting a pH of influent wastewater to less than about 3.5 and thereafter maintaining the pH of the influent wastewater to less than about 3.5; b. removing fluorides and silica in the form of hydrofluorosilicic acid from the wastewater by directing the wastewater through a first reverse osmosis system; c. after initially adjusting the pH of the influent wastewater to less than about 3.5 and after the wastewater has been treated in the first separation system, promoting conditions that favor the formation of fluoride and silicate ions by adjusting the pH of the wastewater upwardly to at least about 6 or higher; and d. directing the wastewater, including the fluoride and silicate ions, through a second reverse osmosis system and removing from the wastewater the fluoride and silicate ions.
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8. A method of removing fluorides from influent wastewater comprising:
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a. directing the wastewater to a first reverse osmosis system and removing fluorides from the wastewater; b. prior to the wastewater entering the first reverse osmosis system, chemically adjusting or maintaining the pH of the wastewater to less than about 3.5; c. directing the wastewater from the first reverse osmosis system to a second reverse osmosis system and removing fluorides from the wastewater; d. adjusting the pH of the wastewater upwardly after the wastewater has been subjected to treatment in the first reverse osmosis system and prior to treatment in the second reverse osmosis system; and e. removing at least 90% of the fluorides from the wastewater with the first and second reverse osmosis systems. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification