pH dependent phosphorus release from waste activated sludge: contributions of phosphorus speciation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 267; pp. 260 - 265
• Main Authors: Xu, Yunfeng, Hu, Hui, Liu, Jianyong, Luo, Jinghuan, Qian, Guangren, Wang, Aijie
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2015
• Subjects: pH dependent; Phosphorus speciation; Release; SMT protocol; Waste activated sludge; Waste activated sludge; pH dependent; SMT protocol; Phosphorus speciation; Release
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2015.01.037

•P release and speciation study from WAS were performed at pH=2–11.•SMT protocol was used for P speciation release tests from WAS.•Release percentages of P fractions are made clear at different pHs.•MINTEQ was used to simulate the phosphate and metal ions release. For phosphorus (P) recovery from waste activated sludge (WAS), the most important step is to release P into the solution, which is greatly dependent on the pH of the solution. The contributions of different P speciation to P release amount from WAS as well as P release kinetics were investigated at different pHs, with the Standards Measurements and Testing (SMT) protocol being used for P fractions tests. The results showed that the total P in the solid (TP(s)) release percentages were 36.2% and 12.4% at pH=2.0 and pH=11.0, respectively. P speciation and fractions study made clear that the released P comes mainly from dissolving of inorganic P (IP) under acid condition, but from non-apatite inorganic P (NAIP) and organic P (OP) under alkaline condition. Simulation study using Visual MINTEQ indicated that the P release amount came from the experimental results is unanimous.