As a promising phosphorus source, phosphorus recovery from sewage sludge ash is necessary to ensure sustainable phosphorus cycle and management. To achieve these targets, a novel strategy including phosphorus capture by acid-resistant adsorbent from acid-extract of sewage sludge ash and repeated enrichment in eluent was first proposed in this study. Over 93% of phosphorus was extracted by H₂SO₄ acidification at pH of 2.0, and a tailored acid-resistant adsorbent recovered almost all the extracted phosphorus in acid-extract of sewage sludge ash. The fitting results of multiple models showed that the rate-limiting step for phosphorus recovery was chemical reaction, and the maximum recovery capacity of acid-resistant adsorbent was 41.7–44.0 mg/g. Characterization results of X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Zeta potential suggested that the recovery mechanism of acid-resistant adsorbent for phosphorus included ligand exchange, inner-sphere complexation and electrostatic attraction. After 8 cycles of recovery-repeated enrichment, the phosphorus in eluent was enriched about 6.7 times. Over 99% of phosphorus in eluent was recovered as struvite by adding external magnesium and ammonium at pH of 8.5. The content of heavy metals in recovered struvite were far below the utilization standard of plant fertilizer, indicating that the phosphorus in sewage sludge ash could be recovered in the form of high-quality phosphorus fertilizer.

作为一种有前途的磷源，从污水污泥灰分中回收磷对于确保可持续的磷循环和管理是必要的。为了实现这些目标，本研究首次提出了一种新的策略，包括从污水污泥灰的酸提取物中通过耐酸吸附剂捕获磷并在淋洗液中重复富集。超过 93% 的磷被 H ₂ SO ₄萃取在 pH 值为 2.0 时进行酸化，特制的耐酸吸附剂回收了污水污泥灰分酸提取物中几乎所有提取的磷。多模型拟合结果表明，磷回收的限速步骤是化学反应，耐酸吸附剂的最大回收量为41.7~44.0 mg/g。X射线光电子能谱、傅里叶变换红外光谱和Zeta电位表征结果表明，耐酸磷吸附剂的回收机制包括配体交换、球内络合和静电引力。经过8个循环的回收-重复富集，淋洗液中的磷富集约6.7倍。通过在 8.5 的 pH 值下添加外部镁和铵，洗脱液中超过 99% 的磷以鸟粪石的形式被回收。