Methods for removing carbon dioxide and other pollutants from a gas stream are provided. The methods include obtaining hydroxide in an aqueous mixture, mixing the hydroxide with the gas stream to produce bicarbonate products or a combination of carbonate and bicarbonate products in an admixture, separating the products from the admixture, and using the products to perform ion-exchanges with one or more group-1 or group-2 salts to precipitate carbonates, wherein obtaining the hydroxide comprises obtaining a group-1 or group-2 salt; mixing the salt with acid and water, acid and steam, or acid, water, and steam to produce a protonated brine solution; and electrolyzing the protonated brine solution to produce a hydroxide; and wherein mixing the hydroxide with the gas stream comprises altering the product equilibrium to favor the production of bicarbonate products.