[Claim 1] [Amended] Nano structured filter beads and nano structured filter powder comprising of a nanosilica component with block copoly merization characteristics uniformly modified and incorporated with iron as ferric sulfate or ferric chloride, wherein: the nano structured filter beads have a particle size of 8.0 nm, pore radius of 17.0 angstroms, surface area of 349 m²/g, dry bulk density of 0.78-0.81 g/cm³, hardness of 1.02-1.71 kg/g; and the nano structured filter powder has a particle size of 36.0 nm, pore radius of 91.0 angstroms, and surface area of 110 m²/g.

[Claim 2] [Cancelled] [Claim 3] [Cancelled] [Claim 4] [Unchanged] A method of preparing nanostructured powder according to Claim 1 comprising the steps of: a. dissolving the nanosilica in 2.5 N NaOH at a ratio of 1:4 (wt. of nanosilica: vol. of base to obtain the silica sol); b. filtering the silica sol to remove the undissolved particles; c. dissolving the iron source (ferric sulfate or ferric chloride) in 2.5 N NaOH; d. filtering the excess iron using a funnel; e. adding the purified nanosilica to the alkaline solution of the iron salt; f. stirring the sol for ten hours; g. titrating the sol with 5 N H₂S0₄ to reduce the pH to 7.5-8.5; h. washing the residue with deionized water; i. air-drying the residue; and j. oven drying the residue at 120-150 °C for three to twelve hours.

[Claim 5] [Unchanged] A method of preparing nanostructured beads according to Claim 1 comprising the steps of: a. dissolving the nanosilica powder in 2.5 N NaOH solution; b. titrating the resulting sodium silicate to glacial acetic acid with stirring until pH 3.5-4.0; c. adding the iron source to the solution and aging the resulting solution for 2-4 hours until a viscosity of 2750 to 3250 cP is achieved; d. dropping the solution of iron modified silica sol slowly to form beads in a column containing ammonium hydroxide with surfactant as the aqueous layer and hexane as the organic layer; e. aging the beads in ammonium hydroxide for at least two hours; f. collecting the iron modified silica beads; g. washing the iron modified silica beads; h. washing the beads with deionized water while undergoing sonication at 50-60 Hz, then with acetone or isopropyl alcohol; i. air-drying the beads; and j. oven-drying the beads at 150-200 °C for three to six hours.

[Claim 6] [Cancelled] [Claim 7] [Cancelled] [Claim 8] [Cancelled] [Claim 9] [Cancelled] [Claim 10] [Cancelled] [Claim 11] [Cancelled] [Claim 12] [Amended] The nanostructured filter powder according to Claim 1, wherein the allowed flow rate is 9.0 mL/min and the adsorption capacity is 0.99-1.02 mg As(III)/g adsorbent.

[Claim 13] [Amended] The nanostructured filter beads according to Claim 1 wherein the allowed flow rate is 600 mL/min and the adsorption capacity is 0.82-0.96 mg As(III)/g adsorbent.

[Claim 14] [Cancelled] [Claim 15] [Cancelled]