NOVELTY - Removing silica from a brine solution, comprises providing the brine solution, maintaining the pH of the brine solution at an adjusted pH of 4-7 and contacting the brine solution with activated alumina at the adjusted pH such that silica present in the brine solution selectively binds to the activated alumina, and recovering an aqueous product stream from the contacting step, where the aqueous product stream has a reduced silica concentration relative to the brine solution.    USE - The method is useful for removing silica from a aqueous brine solution, such as geothermal brine solution (claimed), smackover brines, synthetic brines, and other brines resulting from oil and gas production.    ADVANTAGE - The method selectively removes silica from the aqueous brine solution without removing other ions from the brines, thus eliminating scale deposits in reverse osmosis desalination plants.    DETAILED DESCRIPTION - Removing silica from a aqueous brine solution, comprises either providing the brine solution, maintaining the pH of the brine solution at an adjusted pH of 4-7, contacting the brine solution with activated alumina at the adjusted pH such that silica present in the brine solution selectively binds to the activated alumina, and recovering an aqueous product stream from the contacting step, or providing the aqueous brine solution and an iron(II) salt, oxidizing the iron(II) salt to iron(III) hydroxide, maintaining the pH of the brine solution at 4.5-6, contacting the silica and the iron(III) hydroxide for a time sufficient for the silica to attach to the iron(III) hydroxide and form a silica/iron precipitate, separating the silica/iron precipitate from the aqueous brine solution, and recovering an aqueous product stream from the separation step, or providing a aqueous brine solution, contacting the brine solution with an aqueous solution comprising aluminum chloride to produce a second aqueous solution including brine and aluminum chloride, adjusting and maintaining the pH of the second aqueous solution at 4.5-5.5 to form an aluminosilicate precipitate, removing the aluminosilicate precipitate and recovering an aqueous product stream, where the aqueous product stream has a reduced silica concentration relative to the brine solution.