Preliminary investigation into factors affecting controlled struvite crystallization at the bench scale. Issue 3 (1st May 2004)

• Record Type: Journal Article
• Authors: Adnan, Ali; Dastur, Mazareen; Mavinic, Donald S; Koch, Frederic A
• Is Part Of: Journal of environmental engineering and science. Volume 3:Issue 3(2004)
• Page Start: 195
• Page End: 202
• Publication Date: 2004-05-01
• Subjects: environment; Environmental engineering -- Periodicals; Sanitary engineering -- Periodicals; Environmental engineering -- Canada -- Periodicals; Environnement, Technique de l' -- Périodiques; Technique sanitaire -- Périodiques; Environnement, Technique de l' -- Canada -- Périodiques; Environmental engineering; Sanitary engineering; Canada; Electronic journals; Computer network resources; Periodicals; 628.05
• DOI: 10.1139/s03-082
• Languages: English
• ISSNs: 1496-2551

Abstract

Abstract : A preliminary investigation of factors affecting controlled struvite crystallization was conducted in bench-scale studies using a new crystallization reactor design, operating under a range of reactor and feed strength conditions. In 21 different experiments, it was found that the bench-scale reactor functioned well in terms of achieving good particle classification, although its performance was somewhat restricted in terms of P removal. Reactor operation was generally somewhat compromised because of scale effects. As a preliminary to further (ongoing) pilot-scale investigations, it was found that, for a given set of operating and feed strength conditions, there was a specific value of pH (pHlim ) beyond which the reactor would not operate effectively. The pH value is an important operating parameter in struvite crystallization, and the mode of pH operation plays a major role in determining struvite crystal quality. When operated at pH values exceeding pHlim, poor quality (i.e., dendritic) crystals were produced and reactor plugging often occurred. A qualitative assessment of temperature effects on crystallization reactions suggested that low temperatures may indeed favour struvite crystal growth. Reactor seeding was not found to be a factor of any particular importance since, once struvite crystallization reactions were underway, the reactor appeared to be "self-seeding". Key words : Crystallization, phosphorus removal, struvite, environmental sustainability, bench-scale studies, phosphorus recovery.