Stendahl K, Jäfverström S
Feralco AB, Industrigatan 126, SE-252 32 Helsingborg, Sweden. info@feralco,com
Water Sci Technol. 2003;48(1):185-90.
Supercritical Water Oxidation (SCWO) is an innovative and effective destruction method for organics in sewage sludge. The SCWO process leaves a slurry of inorganic ash in a pure water phase free from organic contaminants, which opens possibilities for a simple process to recover components like phosphates from the sewage sludge. In a continuous pilot plant for the SCWO process digested sludge has been treated. The ash has been extracted in lab scale with both caustic and acids in order to recover phosphates. By leaching the ash with caustic, 90% of the phosphorus could be separated as a sodium phosphate solution. By treating the sodium phosphate solution with lime, calcium phosphate was precipitated and caustic recovered and circulated back to the leaching process.
超临界水氧化（SCWO）是一种用于处理污水污泥中有机物的创新且有效的销毁方法。超临界水氧化过程会在纯净的水相中留下无机灰分的淤浆，且该水相不含有机污染物，这为从污水污泥中回收磷酸盐等成分的简单工艺开辟了可能性。在一个用于超临界水氧化过程的连续中试装置中，已对消化污泥进行了处理。为了回收磷酸盐，已在实验室规模下用苛性碱和酸对灰分进行了提取。通过用苛性碱浸出灰分，90%的磷可作为磷酸钠溶液分离出来。通过用石灰处理磷酸钠溶液，磷酸钙沉淀析出，苛性碱得以回收并循环回到浸出过程。
