Abstract: A fixing carrier for fixing an activated sludge employed in a sewage or waste-water treatment in whicha clay, containing kaolinite minerals, of from 10 to 40 parts by weight and a foaming agent of from 5 to 20 parts by weight are blended with a granulated blast furnace slag of from 60 to 90 parts by weight in the presence of water to prepare a wet mixture which is kneaded and shaped into a shaped mixture; andsaid shaped mixture is baked at a baking temperature of less than 950.degree. C. at maximum, with the proviso that each of a heat-up time required of said shaped mixture to reach said baking temperature for producing a baked product and a heat-down time required of said baked product to reach a temperature of up to 100.degree. C. is about one hour.

Abstract: A fixing carrier for fixing an activated sludge employed in a sewage or waste-water treatment in which:a clay, containing kaolinite minerals, of from 10 to 40 parts by weight and a foaming agent of from 5 to 20 parts by weight are blended with a granulated blast furnace slag of from 60 to 90 parts by weight in the presence of water to prepare a wet mixture which is kneaded and shaped into a shaped mixture; andsaid shaped mixture is baked at a baking temperature of less than 950.degree. C. at maximum, with the proviso that each of a heat-up time required of said shaped mixture to reach said baking temperature for producing a baked product and a heat-down time required of said baked product to reach a temperature of up to 100.degree. C. is about one hour.