HAOXiao-di,GUOXiao-yuan,SHIChen,et al.Advances in the Ash Dec Process for Phosphorus Recovery from Sludge Incineration Ash[J].China Water & Wastewater,2022,38(14):17-24.
Advances in the Ash Dec Process for Phosphorus Recovery from Sludge Incineration Ash
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第14期
Page:
17-24
Column:
Date of publication:
2022-07-17
- Keywords:
- excess sludge; incineration ash; thermochemical method; Ash Dec process; phosphorus recovery; heavy metals
- Abstract:
- The era of phosphorus crisis has appeared on the earth, and thus exploiting “the second phosphate mine” could effectively inhibit the rate of phosphorus scarcity. The incinerated ash of excess sludge is the phosphorus sink of wastewater and is also the best site for phosphorus recovery. Due to the high content of heavy metals in the ash, separation of heavy metals should be performed from the ash prior to phosphorus recovery. Otherwise, the recovered phosphorus is difficult to compete with mined phosphate. After comparing various phosphorus recovery methods from the ash, the Ash Dec process (thermochemical method) is defined as an effective one, as it can apply metal chlorides to achieve heavy metal volatilization and separation. Moreover, heavy metal recovery could be realized in the exhaust gas purification system. A phosphorus?rich phase with high bioavailability then could be obtained. In this work, discussion on Ash Dec process were performed as following: ① The principles of the Ash Dec process are first introduced. ② Factors limiting heavy metal volatilization is then discussed. ③ Engineering cases applied in Europe is listed. ④ Current directives/laws on recovered phosphorus applications is mentioned. ⑤ The potential of the ash used as a raw material for phosphate fertilizer production is elucidated. ⑥ The state?of?art research for recovering heavy metals from the exhaust gas purification system is stated.
Last Update:
2022-07-17