Phosphorus recovery from wastewater is an important approach for sustainable phosphorus use. In this work, a process combining anammox and hydroxyapatite (HAP) precipitation in an expanded bed reactor for simultaneous nitrogen removal and phosphorus recovery was developed by applying specific Ca/P ratio and pH control. A high phosphorus removal rate (0.14 ± 0.01 kg-P/m³/d) was obtained while a stable nitrogen removal efficiency (87.4 ± 2.9%) maintained with an effluent recirculation system applied. Average 13.4% phosphorus (30.7% in P₂O₅) accumulation in the dry sludge and a Ca/P ratio very close to HAP was observed by quantitative elemental analysis. In this work, different analysis revealed the two layers structure with anammox biofilm attached to inorganic core of the granules. Different spectral analysis determined the major phase of the inorganic content as hydroxyapatite. With proper Ca/P ratio and pH control, anammox expanded bed reactor was transformed into an efficient process to simultaneously remove nitrogen and recover phosphorus.

从废水中回收磷是可持续利用磷的重要方法。在这项工作中，通过应用特定的Ca / P比和pH值控制，开发了一种在膨胀床反应器中将厌氧氨氧化和羟基磷灰石（HAP）沉淀相结合的工艺，以同时去除氮和回收磷。在采用废水再循环系统的情况下，获得了较高的除磷率（0.14±0.01 kg-P / m ³ / d），同时保持了稳定的除氮效率（87.4±2.9％）。平均磷13.4％（P ₂ O _5为30.7％通过定量元素分析观察到干污泥中的累积和Ca / P比非常接近HAP。在这项工作中，不同的分析揭示了两层结构，其厌氧菌生物膜附着在颗粒的无机核上。不同的光谱分析确定了无机成分的主要相为羟基磷灰石。在适当的Ca / P比和pH值控制的条件下，厌氧氨氧化膨胀床反应器已转化为高效的工艺，可同时去除氮并回收磷。