Host: Japan Society of Material Cycles and Waste Management
Investigation of phosphorus recovering conditions from carbonized sewage sludge was carried out using sodium hydroxide. Carbonized sewage sludge was mixed with an aqueous solution of sodium hydroxide, and treated at 120degree. After this treatment, phosphorus was extracted by a hot-water extraction processes and cooled to 5degree for crystallization of sodium phosphate. In order to concentrate the phosphorus in the extracted water, introduction of the low S/L ratio-extraction method was investigated. The phosphorus recovery rate was estimated to be about 63% to 70%. Recovered phosphorus was considered Na3PO4, from X-Ray analysis. NaOH remaining in the processes water was identified to be reused as alkali of phosphorus extraction.
