Abstract It is highly imperative to remove phosphorus from water bodies because the excessive phosphorus content can cause eutrophication of water bodies. In this work, we prepare a kind of environmentally friendly and low-cost adsorbent comprising lanthanum (La)-doped bentonite and chitosan, with a simple, facile and scalable method combining direct calcination and subsequent blending. The optimal adsorbent, La-doped bentonite/chitosan-5, La-BC-5 hereinafter, can rapidly reach equilibrium in 20 min and provide 93.2% adsorption efficiency (initial phosphate concentration, 50 mg/L); and as high as 99.7% could be removed in 5 min under low phosphate concentration (2 mg/L). Fitting result indicates the phosphate adsorption isotherm fits the Freundlich model, meanwhile the adsorptive kinetics follows a pseudo-second-order model. Anti-interference result for some typical anionic species including NO3−, SO42−, Cl−, indicates 97.5% removal efficiency could be achieved under coexisting phosphate concentration of 5 mg/L. Meanwhile, reusability experiment reveals that removal efficiency decreases to 89.1% after five regeneration cycles. Notably, practical water adsorption experiment manifests the La-BC-5 can efficiently reduce the phosphate concentration from 0.30 to 0.07 mg/L. The favorable properties with rapid adsorption, excellent anti-interference for coexisting anions and reusability foresee the enormous potentials for practical phosphate removal in water bodies.

中文翻译：

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La(III)-膨润土/壳聚糖复合材料：一种新型吸附剂，可快速去除水体中的磷酸盐

摘要 水体中磷含量过高会导致水体富营养化，因此对水体进行除磷迫在眉睫。在这项工作中，我们采用直接煅烧和后续共混相结合的简单、简便和可扩展的方法制备了一种包含镧 (La) 掺杂膨润土和壳聚糖的环保低成本吸附剂。最佳吸附剂La掺杂膨润土/壳聚糖5，以下简称La-BC-5，可在20分钟内迅速达到平衡，吸附效率为93.2%（初始磷酸盐浓度50mg/L）；在低磷酸盐浓度（2 mg/L）下，5 分钟内可去除高达 99.7%。拟合结果表明磷酸盐吸附等温线符合Freundlich模型，同时吸附动力学遵循准二级模型。一些典型的阴离子物质（包括 NO3-、SO42-、Cl-）的抗干扰结果表明，在 5mg/L 的共存磷酸盐浓度下可以实现 97.5% 的去除效率。同时，可重复使用性实验表明，经过 5 次再生循环后，去除效率降至 89.1%。值得注意的是，实际的水吸附实验表明，La-BC-5 可以有效地将磷酸盐浓度从 0.30 降低到 0.07 mg/L。具有快速吸附、对共存阴离子的优异抗干扰性和可重复使用性的有利特性预示着在水体中实际去除磷酸盐的巨大潜力。重复使用性实验表明，经过 5 次再生循环后，去除效率降至 89.1%。值得注意的是，实际的水吸附实验表明，La-BC-5 可以有效地将磷酸盐浓度从 0.30 降低到 0.07 mg/L。具有快速吸附、对共存阴离子的优异抗干扰性和可重复使用性的有利特性预示着在水体中实际去除磷酸盐的巨大潜力。重复使用性实验表明，经过 5 次再生循环后，去除效率降至 89.1%。值得注意的是，实际的水吸附实验表明，La-BC-5 可以有效地将磷酸盐浓度从 0.30 降低到 0.07 mg/L。具有快速吸附、对共存阴离子的优异抗干扰性和可重复使用性的有利特性预示着在水体中实际去除磷酸盐的巨大潜力。