Lanthanum (La) adsorbents are highly effective for phosphorus removal but are constrained by their high reagent cost because of their La content. By exploiting the similarity in ionic sizes between Ca²⁺ and La³⁺, we develop a low-cost composite adsorbent LCCa-5@Dia by doping La₂(CO₃)₃·8H₂O with Ca²⁺. Our results indicate that the slow addition of NaHCO₃ during the synthetic process facilitates the incorporation of Ca²⁺ into the La₂(CO₃)₃·8H₂O lattice, leading to an adsorption behavior nearly identical to that of the undoped adsorbents. LCCa-5@Dia demonstrates a maximum adsorption capacity of 60.04 mg P/g, with stable performance across a pH range of 3 to 11. Its adsorption property also exhibits excellent stability under the interference of solution pH and competing ions. Materials characterization reveals that the adsorption occurs through electrostatic attraction and ligand exchange. In continuous column-adsorption experiments, the LCCa-5@Dia adsorbent treats up to 4000 bed volumes of simulated low concentration wastewater (1.7–2.7 mg P/L). This translates to a treatment cost as low as $0.0211/m³. Meanwhile, the adsorbent also maintains over 80 % of the adsorption capacity after three regeneration cycles. The excellent performance and low treatment cost of the calcium-doped lanthanum carbonate adsorbents highlight its practical potential in treating low concentration wastewater.

中文翻译：

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通过掺钙碳酸镧吸附剂从低浓度废水中连续除磷


镧 （La） 吸附剂对除磷非常有效，但由于其 La 含量，其试剂成本高而受到限制。通过利用 Ca²⁺ 和 La³⁺ 之间离子尺寸的相似性，我们通过将 La₂（CO₃）₃·8H₂O 与 Ca²⁺ 掺杂开发了一种低成本的复合吸附剂 LCCa-5@Dia。我们的结果表明，在合成过程中缓慢添加 NaHCO₃ 有助于 Ca²⁺ 掺入 La₂（CO₃）₃·8H₂O 晶格中，导致吸附行为与未掺杂吸附剂几乎相同。LCCa-5@Dia 的最大吸附容量为 60.04 mg P/g，在 3 至 11 的 pH 范围内具有稳定的性能。其吸附性能在溶液 pH 值和竞争离子的干扰下也表现出优异的稳定性。材料表征表明，吸附是通过静电吸引和配体交换发生的。在连续柱吸附实验中，LCCa-5@Dia 吸附剂可处理多达 4000 床体积的模拟低浓度废水 （1.7–2.7 mg P/L）。这意味着处理成本低至 0.0211 USD/m³。同时，吸附剂在三个再生循环后仍能保持 80% 以上的吸附容量。掺钙碳酸镧吸附剂的优异性能和低处理成本凸显了其在处理低浓度废水方面的实际潜力。