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US 2020/0140288 A1Published application
Activated rice husk filters, filter media, and methods
AssigneeGlanris Water Systems, Inc.
InventorL-YU Lin
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Abstract
The inventive subject matter disclosed herein includes multiple novel filter media made of activated rice husks, as well as filtration systems and methods for removing contaminants from an aqueous solution, such as wastewater produced as a byproduct of various industrial processes, including mining, oil and gas exploration and extraction, farming, manufacturing, and the like.
Claims16
A method to remove a plurality of heavy metals from an aqueous solution comprising:
- a method of making activated partially charred rice husks consisting of providing rice husks,
- exposing the rice husks to a heat source to heat the rice husks to a temperature of between about 250° C. and about 550° C. for a period of between about 1 to about 10 minutes in at atmosphere having less than 2 percent oxygen in order to at least partially char the rice husks;
- removing the partially charred rice husks from the heat source,
- cooling the partially charred rice husks to an ambient temperature, and
- affixing a cation to the partially charred rice husks;
- wherein the activated partially charred rice husks have a silicon content of not greater than 40 percent, range from between about 0.5 mm to about 5 mm in length, have a specific surface area of between 400-500 m2/g, and have a porosity between 0.4 to 0.55;
- and
- passing the aqueous solution through said activated partially charred rice husks to remove the heavy metals from the aqueous solution.
5 more elements
The method of claim 2, further comprising the steps of:
- mixing the partially charred rice husks with a sufficient amount of 80/20 volume ethanol/butanol to activate the partially charred rice husks;
- mixing a 20 percent by weight of CaOH to form a mixture;
- soaking the mixture for about two hours at room temperature;
- adding a sufficient amount of a weak acid to the mixture to affix a calcium cation to the partially charred rice husks;
- and
- washing the mixture with a strong acid to affix the calcium cation to the partially charred rice husks;
- and drying the mixture at 150-170° C. for several hours to form the activated partially charred rice husks.
4 more elements
A method to remove a heavy metal from an aqueous solution containing a plurality of heavy metals comprising:
- providing an activated carbon filtration media, wherein the activated carbon filtration media consists of:
- activated partially charred rice husks, said activated partially charred rice husks have a silicon content of not greater than 40 percent, range from between about 0.5 mm to about 5 mm in length, have a specific surface area of between 400-500 m2/g, and have a porosity between 0.4 to 0.55;
- and
- contacting the activated carbon filtration media with the aqueous solution containing the plurality of heavy metals to remove a heavy metal from the aqueous solution;
- regenerating the activated partially charred rice husks by washing the charred rice husks with an aqueous acid solution;
- and
- passing the aqueous solution through the regenerated activated partially charred rice husks to further remove heavy metals from the aqueous solution.
4 more elements
Dependencies are inferred from the claim text.