SLUDGE TREATING METHOD, AND METHOD AND APPARATUS FOR TREATING ORGANIC WASTE WATER USING THE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a sludge treating method by which phosphorus is easily reused and the discharging amount of the phosphorus component is reduced by separating/recovering the phosphorus component as polyphosphoric acid with a high rate by using a simplified system in a method for treating organic wastewater. SOLUTION: This sludge treating method comprises a heating step to heat the sludge to be treated at 60-90 deg.C for 10-120 minutes for releasing the phosphorus component into the liquid phase, a liquid temperature adjusting step to adjust the liquid temperature of the treated liquid after the phosphorus component is released to 70 deg.C or lower, a solid-liquid separation step to separate the treated liquid after the liquid temperature is adjusted into treated water and sludge and a phosphorus flocculating step to precipitate the phosphorus in the treated water, which is obtained by the solid-liquid separation, from the liquid phase at reaction temperature of 20-70 deg.C by adding a flocculant. Further, there are provided a method for treating organic waste water containing the above steps, and an apparatus therefore.