Aiming at the development of a filter material that can be used for livestock wastewater treatment, a sintered filter was manufactured by combining recycled carbon with ceramics. We investigated the possibility of applying this filter to the decolorization treatment of the color-causing substances contained in wastewater. Humic acid was used as a model of the color-causing substances. The possibility of regenerating a carbon-ceramic sintered filter after the adsorption treatment by heat treatment and repeated use was examined. When an aqueous solution of sodium humic acid was poured into the sintered carbon-ceramic filter, it was found that it has a high adsorption capacity for humic acid. However, when the aqueous solution was continuously poured, the adsorption rate of humic acid decreased. When the sintered carbon-ceramic body used in the adsorption experiment was heat-treated in an air atmosphere, the adsorption capacity was restored through the heat treatment at 400 °C to 500 °C. From the above, it was shown that a sintered carbon-ceramic body can be an effective adsorbent for humic acid, which is a coloring substance for livestock wastewater and can be repeatedly used for heat treatment.