The Feasibility Study on Dewatering and Recoveringg Organic Solids From Sewage Sludge Using Reduced Pressure Distillation Process With Oil

• Main Authors: Ching-Yun Chang, 張景雲
• Other Authors: Kuen-Sheng Wang
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/85528935193145762885

碩士 === 國立中央大學 === 環境工程研究所 === 87 === With the fast economic growth, and the increase in the population served by sewer system, the volume of sewage sludge generated by the pipe end treatment plants is constantly increasing, calling for proper treatment, disposal, and resource recovery. The sewage sludge contains various organic and inorganic substances, and is re-valuated as valuable resources rather than wastes. The organic rich solid in the sludge can be recovered for various uses such as the amendment for fertilizer. This study investigated the feasibility of dewatering and recovering organic solids from the sewage sludge cake without any destruction of the its organic, by applying a reduced-pressure-distillation process which uses oil as a heat conducting medium. The results indicate that, in general, the process is fundamentally governed by the heating temperature and the degree of reduced pressure. The recovery efficiency increases with the increasing heating temperature, operation time, the degree of reduced pressure, and the oil-sludge ratio. The properly processed sludge contains less than 5% residual oil, and moisture, respectively. This recovered organic solids, being low in electrical conductivity (0.71 ms/cm), and in heavy metal concentrations of the TCLP leachate, is stable, nutritious and suitable for the use as fertilizer amendment.