The influence of various process parameters on dissolution kinetics and mechanism of struvite seed crystals
MetadataShow full item record
The basic understanding of struvite dissolution chemistry is essential to designers and operators for anticipating struvite problem and remediating existing struvite damage in a wastewater treatment. The dissolution kinetic of struvite seed crystals is very important parameters to determine a solid substance entering in solvent to yield a solution. In this study the dissolution kinetics of struvite crystals (MgNH4PO4·6H2O) in deionized water was investigated in a batch crystallizer. The effects of stirrer speeds, temperature and seed crystals size on the dissolution rate were determined. The results showed that an increase of struvite dissolution rate with increasing stirring speed. Struvite dissolution occurred via a diffusion-controlled mechanism in the range of stirrer speeds 120–400 rpm but became interfacial-reaction-controlling at over 400 rpm. The influence of temperature on dissolution kinetic of struvite crystals was also investigated at stirrer speeds of 200 and 500 rpm. The dissolution rates increased with an increase in the temperature for both stirrer speeds. The change in activation energies at different stirrer speeds confirmed that the change of dissolution mechanism from a diffusion-controlled mechanism at low stirrer speeds to an interfacial-reaction-controlled mechanism at higher stirrer speeds. The dissolution rate of struvite crystals increased with smaller crystal sizes.
© The Institution of Engineers (India) 2017
Showing items related by title, author, creator and subject.
Liew, Emily Wan Teng (2011)Mixing plays a substantial role in determining the overall performance of a bioreactor. Well mixing in bioreactor, especially for ethanolic fermentation process is important for the homogenization of miscible and immiscible ...
The influence of various physico-chemical process parameters on kinetics and growth mechanism of struvite crystallisationAriyanto, Eko; Sen, Tushar; Ang, Ha Ming (2014)In response to struvite formation problems in wastewater treatment plants (WWTP), this mechanistic growth kinetic study of struvite crystal (MgNH4PO4.6H2O) was undertaken to determine the cause of preferential accumulation ...
Mechanism and kinetics of pseudomorphic mineral replacement reactions: A case study of the replacement of pentlandite by violariteXia, F.; Brugger, J.; Chen, G.; Ngothai, Y.; O'Neill, B.; Putnis, Andrew; Pring, A. (2009)Although pseudomorphic mineral replacement reactions are common in all geological environments, and have long been considered important to many geological processes such as metamorphism, metasomatism, diagenesis, and ...