Time-Resolved Dynamics of Struvite Crystallization: Insights from the Macroscopic to Molecular Scale

Doyoung Kim, Chara Olympiou, Colin McCoy, Nicola Irwin, Jeffrey Rimer

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)
376 Downloads (Pure)


The crystallization of magnesium ammonium phosphate hexahydrate (struvite) often occurs under conditions of fluid flow, yet the dynamics of struvite growth under these relevant environments has not been previously reported. In this study, we use a microfluidic device to evaluate the anisotropic growth of struvite crystals at variable flow rates and solution supersaturation. We show that bulk crystallization under quiescent conditions yields irreproducible data owing to the propensity of struvite to adopt defects in its crystal lattice, as well as fluctuations in pH that markedly impact crystal growth rates. Studies in microfluidic channels allow for time‐resolved analysis of seeded growth. Having first identified flow rates that differentiate diffusion and reaction limited growth regimes, we operated solely in the latter regime to extract the kinetic rates of struvite growth along all principle crystallographic directions. In situ atomic force microscopy was used to obtain molecular level details of surface growth mechanisms. Our findings reveal a classical pathway of crystallization by monomer addition with the expected transition from growth by screw dislocations at low supersaturation to that of 2‐dimensional layer generation and spreading at high supersaturation. Collectively, these studies present a platform for assessing struvite crystallization under flow conditions and demonstrate how this approach is superior to measurements under quiescent conditions.
Original languageEnglish
Pages (from-to)3555
JournalChemistry - A European Journal
Issue number16
Publication statusPublished - 19 Nov 2019


Dive into the research topics of 'Time-Resolved Dynamics of Struvite Crystallization: Insights from the Macroscopic to Molecular Scale'. Together they form a unique fingerprint.

Cite this