Nucleation in the formation of struvite: state of art

ABSTRACT Recent estimation for the duration of global phosphate reserves does not exceed 400 years and the production of nitrogen fertilizers is energetically unsustainable. Nowadays, wastewater treatment plants have been seen as resource recovery facilities (water, energy and nutrients) instead of “end-of-pipe” utilities. Thus, nutrient-recovery technologies should be prioritized over the removal ones. Struvite (phosphate of ammonium and magnesium) is a crystal, produced from sewage, with a higher agricultural efficiency when compared to conventional fertilizers. Despite the crystallization is a topic extensively studied worldwide and highly technologically developed, its use in sanitary engineering is still not common, especially in Brazil. As the aspects related to struvite nucleation have been insufficiently studied, this paper presents a critical and updated literature review, and shows the gaps in the current knowledge about this topic.

摘要
近期估算结果显示，全球磷酸盐（phosphate）储量的可使用年限不超过400年，且氮肥的生产在能源层面难以持续。如今，污水处理厂已被定位为可回收水资源、能源与营养物质的资源回收设施，而非单纯的"末端治理"设施。因此，营养物质回收技术应优先于营养脱除技术得到发展。鸟粪石（Struvite，即磷酸铵镁）是一种由污水生成的晶体，其农业利用效率高于传统化肥。尽管结晶技术这一主题在全球范围内已得到广泛研究且技术高度成熟，但其在卫生工程领域的应用仍不普及，在巴西尤为如此。鉴于与鸟粪石成核相关的诸多方面尚未得到充分研究，本文开展了一项批判性且更新及时的文献综述，并梳理了当前该领域研究存在的知识空白。