Investigating the crystallization pathways of struvite using in-situ liquid-phase and cryogenic transmission electron microscopy

磷的天然供应在世界范围内正在枯竭，岩磷被认为是一种关键资源。这种情况促使人们探索从替代来源提取磷的新方法。一种这样丰富的磷酸盐资源是在城市和工业废水中，其中磷是丰富的，并且可以通过矿物鸟粪石（磷酸铵镁）的结晶来提取。鸟粪石可以直接用于肥料，从而有助于保护有限的磷资源。然而，这种回收过程的效率取决于鸟粪石结晶机制和途径的更好的理解。只有掌握了这些知识，才能有效地从废水中回收磷酸盐，并减少磷对水环境的影响和对磷资源的需求。以前曾研究过从水介质中形成鸟粪石，但大多是通过非直接方法，这些方法已被证明存在各种人为因素。因此，仍然缺乏对该过程的有效和简单的机械理解。我建议在这里使用的组合，在原位液相和低温透射电子显微镜遵循在真实的时间鸟粪石从初始离子到最终固体的所有结晶阶段。这两种技术的最新进展提高了我们在成核和生长方面的知识，但以前从未将它们应用于同一系统。液相和低温透射电子显微镜可以一起用于通过成像和显微光谱分析过程的展开来获得高度动态（在高时间和空间分辨率下）的信息。通过这个科学网络，我的目标是汇集液体电池和冷冻技术和工艺方面的世界级专家，并应用他们更好地了解鸟粪石的结晶途径。

Natural supplies of phosphorus are depleting worldwide and rock phosphorous is considered a critical resource. This situation has led to the exploration of new methods to extract phosphorus from alternative sources. One such abundant resource of phosphate is in municipal and industrial wastewaters where phosphorous is abundant and can be extracted via crystallization of the mineral struvite (magnesium ammonium phosphate). Struvite can then directly be used in fertilizers, thus helping to conserve finite phosphorus resources. However, the efficiency of this recovery process depends on an improved understanding of struvite crystallisation mechanisms and pathways. Only with such knowledge will the recovery of phosphate from wastewater be efficient and the environmental impact of phosphorous on the aquatic environment and the demand on phosphorus resources be reduced.The formation of struvite from aqueous media has been studied before, but mostly via non-direct methods which have been proven to suffer from various artefacts. Thus an efficient and simple mechanistic understanding of the process is still lacking. I propose here to use a combination of in-situ liquid-phase and cryogenic transmission electron microscopy to follow in real time all the crystallisation stages of struvite from initial ions to final solids. Recent advances in both techniques have improved our knowledge in nucleation and growth, but never before have they been applied to the same system. Together, liquid-phase and cryogenic transmission electron microscopy can be used to derive highly dynamic (both at high temporal and spatial resolution) information through imaging and micro-spectroscopic analyses of a process as it unfolds. With this science network I aim to bring together world class experts in liquid-cell and cryo technologies and processes and apply them to gain a better understanding of the crystallisation pathways of struvite.