A solid material prepared from concrete sludge, PAdeCS (R), an industrial waste consisting of surplus concrete from concrete product industries and construction sites, was applied to a phosphorus recovery process with a packed-bed flow system. Sieved particles of PAdeCS were packed in a plastic column, and a model wastewater of pH 7 containing 100 mg-P/L of potassium dihydrogen phosphate (KH2PO4) was fed into the column. The concentration of phosphorus in the effluent solution remained as low as about 0.1 mg-P/L before the breakthrough time and increased rapidly there-after. The amount of model wastewater that can be treated by the present system was found to increase with the height of the packed layer. The removal of phosphorus is thought to occur by the formation of hydroxyapatite (HAP) from calcium ions and hydroxyl ions dissolved from the hydrated cement components in PAdeCS and phosphorus ions in the model wastewater. The formation of HAP occurred at the surface of the packed layer of PAdeCS as well as the formation of HAP crystals in the bulk solution phase. The ratio of HAP formation, which is equivalent to the phosphorous recovery ratio, was found to depend on the height of the PAdeCS layer and the flow rate of the model wastewater.