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Methods for removing substances from aqueous solutions

  • US 5,045,214 A
  • Filed: 05/31/1989
  • Issued: 09/03/1991
  • Est. Priority Date: 03/21/1983
  • Status: Expired due to Fees
First Claim
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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:

  • (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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