Creation of an iron product for wastewater treatment
An embodiment provides a method for making a non-hazardous iron product for treating wastewater, including: adding sodium bisulfite to a solution comprising iron, creating an aqueous solution; adding an amount of sodium hydroxide to the aqueous solution to increase the pH of the aqueous solution to between 2-2.5; determining an amount of sodium bicarbonate and adding the identified amount of sodium bicarbonate to the aqueous solution, wherein the sodium bicarbonate adjusts the pH of the aqueous solution to a desired pH; and providing a buffer to the aqueous solution to generate a slurry. Other embodiments are described and claimed.
1 . A method of making an iron product, the method comprising:
providing an aqueous solution comprising ferrous iron as at least one of ferrous chloride and ferrous sulfate, the aqueous solution comprising ferrous iron having a first pH; and
adding carbonate or bicarbonate to the aqueous solution comprising ferrous iron to increase the pH of the aqueous solution to a desired pH to produce the iron product,
wherein the iron product includes at least 5 weight % of iron content that consists primarily of Fe 2+ and Fe(OH) 2 , and
wherein the carbonate or bicarbonate is only added to the aqueous solution comprising ferrous iron when the aqueous solution has a pH of 0.8 or greater.
2 . The method of claim 1 , wherein the ferrous iron comprises ferrous chloride.
3 . The method of claim 1 , wherein the ferrous iron comprises ferrous sulfate.
4 . The method of claim 1 , wherein the first pH is less than 0.8.
5 . The method of claim 1 , wherein the desired pH is in a range of from 3 to 5.
6 . The method of claim 1 , wherein the desired pH is in a range of from 4 to 5.
7 . The method of claim 1 , wherein the iron product is an iron-containing slurry.
8 . The method of claim 7 , further comprising measuring an infrared spectrum of the slurry.
9 . The method of claim 1 , further comprising capturing carbon dioxide that is generated during the method of making the iron product using a caustic scrubber.
10 . The method of claim 1 , further comprising adding, to the aqueous solution, at least one additional agent from the group consisting of dispersants, anti-oxidants, and anti-clumping agents.
11 . The method of claim 1 , further comprising adding bisulfite to the aqueous solution.
12 . The method of claim 1 , further comprising adding a non-CO 2 emitting alkali to the aqueous solution to increase the pH of the aqueous solution from the first pH to a second pH that is intermediate the first pH and the desired pH.
13 . The method of claim 12 , wherein the non-CO 2 emitting alkali is sodium hydroxide.
14 . A method of treating wastewater to sequester sulfides in the wastewater comprising contacting the wastewater with the slurry of claim 7 .
15 . A method of making an iron product, comprising:
providing an aqueous solution comprising iron and having a first pH; and
adding a non-CO 2 emitting alkali to the aqueous solution to increase the pH of the aqueous solution from the first pH to a second pH that is in a range of from 0.8 to 2,
adding carbonate or bicarbonate to the aqueous solution to increase the pH of the aqueous solution from the second pH to a desired pH, the second pH being intermediate the first pH and the desired pH.
16 . The method of claim 15 , wherein bisulfite is added to the aqueous solution before the non-CO 2 emitting alkali is added to the aqueous solution.
17 . The method of claim 15 , wherein bisulfite is added to the aqueous solution after the non-CO 2 emitting alkali is added to the aqueous solution.
18 . The method of claim 15 , wherein the non-CO 2 emitting alkali is sodium hydroxide.