Alkaline-treated zeolite based sorbent device, and use for heavy metal removal
A sorbent device based on a porous membrane bag (e.g., porous propylene membrane bag) encapsulated alkaline-modified zeolite (e.g., alkaline-treated USY zeolite). A process for removing heavy metals, such as Cd(II), Cr(III), and Pb(II) from an aqueous solution or an industrial wastewater samples with the sorbent device is provided. A method for preparing the alkaline-modified zeolite is also described.
1. A sorbent device, comprising:
an alkaline-treated zeolite; and
a porous membrane bag encapsulating the alkaline-treated zeolite,
wherein the alkaline-treated zeolite comprises an ultrastable Y (USY) zeolite comprising a molar ratio of Si to Al in a range of 15:1 to 25:1, a Brunauer-Emmet-Taylor (BET) surface area in a range of 680 to 750 m 2 /g, and an adsorption capacity in a range of 2 to 100 mg Cr(III) per gram, 1 to 75 mg Pb(II) per gram, and 0.4 to 50 mg Cd(II) per gram.
2. The sorbent device of claim 1 , wherein the alkaline-treated zeolite comprises a faujasite zeolite.
3. The sorbent device of claim 1 , wherein the alkaline-treated zeolite is in a form of particles having an average particle diameter in a range of 300-600 nm.
4. The sorbent device of claim 1 , wherein the alkaline-treated zeolite has an average pore diameter in a range of 13-40 nm, and a total pore volume in a range of 0.8-1.2 cm 3 /g.
5. The sorbent device of claim 1 , wherein the porous membrane bag has an average pore size in a range of 0.05-0.5 μm.
6. The sorbent device of claim 1 , wherein the porous membrane bag comprises at least one polymer selected from the group consisting of polypropylene, polyethylene, nylon, polyvinylidene fluoride, and polyethersulfone.
7. The sorbent device of claim 6 , wherein the porous membrane bag consists of the polypropylene.
8. The sorbent device of claim 1 , wherein the porous membrane bag comprises a porous membrane having an average thickness in a range of 10-500 μm.
9. The sorbent device of claim 1 , wherein 0.5-500 mg of the alkaline-treated zeolite is present per cm 2 exterior surface area of the porous membrane bag.
10. The sorbent device of claim 1 , wherein the porous membrane bag permanently seals in the alkaline-treated zeolite.
11. The sorbent device of claim 1 , wherein the alkaline-treated zeolite comprises particles in a form of octahedrons having a microscopically smooth surface.