Verfahren zum Rückgewinnen von Phosphat aus Schlamm und System dafür

摘要

A method for recovering phosphate from sludge includes the processes of treating sludge drawn from a water treatment system at a sewage treatment plant in an anaerobic condition to release polyphosphate accumulated in the sludge into solution, and recovering phosphate in the solution using a seed crystal material. A system for recovering phosphate from sludge includes a phosphorus-releasing means for treating sludge drawn from a water treatment system at a sewage treatment plant in an anaerobic condition to release phosphate into the bulk liquid, a dewatering and separating means for separating the sludge containing the solution including the released phosphate into dewatering effluent and dewatered sludge, a calcium ion concentration-adjusting means for adjusting the calcium ion concentration in the dewatering effluent, a pH-adjusting means for adjusting the pH of the dewatering effluent, and a crystallizing means for recovering phosphate from the calcium ion concentration-adjusted, pH-adjusted effluent of dewatering apparatus.