The potential of the formation of anammox-hydroxyapatite (HAP) granule composites as a cost-effective approach to removing nitrogen and phosphorus in the treatment of wastewater has been recently reported. Before these annamox granules, which consist of an anammox biofilm layer and an HAP crystallizing layer, can be used in applications, the formation mechanism of hydroxyapatite (HAP) encapsulation in the granules needs to be further studied. In this work, the role of extracellular polymeric substance (EPS) secreted by microorganisms and HAP core in Ca and P removal in anammox-HAP coupled granular sludge was investigated. According to the Lamer model, it is possible that the nucleation time of the granules becomes shorter as the crystal seeds. The enhanced buffering capacity of the granules was 0.08 mmol-H⁺ SS-g⁻¹ with the pH kept above 6.5 for a comfortable environment for anammox. The results of this study show that ion competition and exchange, mainly between cations of Ca²⁺ and Mg²⁺ and between anions of PO₄³⁻ and CO₃²⁻, affects the precipitation process. The results of this study indicate that the addition of granule crystal seeds can be used as a strategy to hasten the anammox process, and therefore accelerate the overall process.

最近已经报道了形成厌氧羟基-羟基磷灰石（HAP）颗粒复合物作为在废水处理中去除氮和磷的经济有效方法的潜力。在由厌氧菌生物膜层和HAP结晶层组成的这些annamox颗粒可用于应用之前，需要进一步研究羟基磷灰石（HAP）包封在颗粒中的形成机理。在这项工作中，研究了微生物和HAP核心分泌的细胞外聚合物（EPS）在厌氧-HAP耦合颗粒污泥中去除Ca和P的作用。根据Lamer模型，颗粒的成核时间可能随着晶种变短。颗粒的增强缓冲能力为0.08 mmol-H ⁺pH保持在6.5以上的SS-g ^-1为厌氧氨氧化提供了舒适的环境。研究结果表明，离子的竞争和交换主要影响Ca ²⁺和Mg ^2+的阳离子之间以及PO ₄ ³⁻和CO ₃ ^2−的阴离子之间的竞争和交换，从而影响沉淀过程。这项研究的结果表明，添加颗粒状晶种可以用作加速厌氧氨氧化过程的策略，从而加快整个过程。