Abstract：
Wet-chemically recovering phosphorus (P) from sewage sludge incineration ash (SSIA) has already become a global initiative to address P deficit, but effectively isolating P from these accompanying metals (AMs) through adsorption in a SSIA-derived extract remains elusive. Here, we devised a hydrothermal stimulus-motivated thermodynamic and kinetic enhancement to gain anionic ethylenediaminetetraacetic acid (EDTA) molecular interfaces for AM enclosure to resolve this conundrum. A new dosage rule based on the EDTA coordination ratio with AMs was established for the first time. Upon hydrothermal extraction at 140 °C for 1 h, the P extraction efficiency reached 96.7% or higher for these obtained SSIA samples, and then exceptional P sequestration from these EDTA-chelated AMs was realized by the peculiar lanthanum (La)-based nanoadsorbent (having 188.86 mg P/g adsorbent at pH ∼ 3.0). Relevant theoretical calculations unraveled that these delocalized electrons of tetravalent EDTA molecules boosted the enclosure of liberated AMs, thereby entailing a substantially increased negative adsorption energy (-408.7 kcal/mol) of P in the form of H2PO4- through intruding lattice-edged carbonates to coordinate La with monodentate mononuclear over LaCO5(1 0 1). This work highlights the prospect of molecular adaptation of these common extractants in wet-chemical P recovery from various P-included wastes, further sustaining global P circularity.
摘要：
从污水污泥焚烧灰（SSIA）中湿法化学回收磷（P）已经成为解决磷短缺的全球倡议，但是通过在SSIA衍生的提取物中吸附有效地从这些伴随的金属（AM）中分离P仍然难以捉摸。这里,我们设计了水热刺激驱动的热力学和动力学增强，以获得用于AM外壳的阴离子乙二胺四乙酸（EDTA）分子界面，以解决这一难题。首次建立了基于EDTA与AMs配合比的新剂量规则。在140°C水热萃取1小时后，这些获得的SSIA样品的P提取效率达到96.7%或更高，然后通过特殊的镧（La）基纳米吸附剂（在pH〜3.0时具有188.86mgP/g吸附剂）实现了这些EDTA螯合AMs的特殊P螯合。相关的理论计算揭示了四价EDTA分子的这些离域电子促进了释放的AM的封闭，因此，通过侵入晶格边缘的碳酸盐以将La与LaCO5（101）上的单齿单核配位，从而导致H2PO4-形式的P的负吸附能（-408.7kcal/mol）大大增加。这项工作突出了这些常见萃取剂在从各种含磷废物中回收湿化学磷的分子适应前景。进一步维持全球P循环。
