College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China.
College of Environmental Science and Engineering, Beijing Key Lab for Source Control Technology of Water Pollution, Beijing Forestry University, Beijing 100083, China.
J Environ Sci (China). 2022 Mar;113:26-39. doi: 10.1016/j.jes.2021.05.041. Epub 2021 Jun 14.
Cationic hydrogels have received great attention to control eutrophication and recycle phosphate. In this study, a type of La(OH) loaded magnetic MAPTAC-based cationic hydrogel (La(OH)@MMCH) was developed as a potential adsorbent for enhanced phosphate removal from aqueous environment. La(OH)@MMCH exhibited high adsorption capacity of 105.72±5.99 mg P/g, and reached equilibrium within 2 hr. La(OH)@MMCH could perform effectively in a wide pH range from 3.0 to 9.0 and in the presence of coexisting ions (including SO, Cl, NO, HCO, SiO and HA). The adsorption-desorption experiment indicated that La(OH)@MMCH could be easily regenerated by using NaOH-NaCl as the desorption agent, and 73.3% adsorption capacity remained after five cycles. Moreover, La(OH)@MMCH was employed to treat surface water with phosphate concentration of 1.90 mg/L and showed great removal efficiency of 95.21%. Actually, MMCH showed high surface charge density of 34.38-59.38 meq/kg in the pH range from 3.0 to 11.0 and great swelling ratio of 3014.57% within 24 h, indicating that MMCH could produce the enhanced Donnan membrane effect to pre-permeate phosphate. Furthermore, the bifunctional structure of La(OH)@MMCH enabled it to capture phosphate through electrostatic attraction and ligand exchange. All the results prove that La(OH)@MMCH is a promising adsorbent for eutrophication control and phosphate recovery.
阳离子水凝胶在控制富营养化和回收磷酸盐方面受到了广泛关注。本研究开发了一种负载 La(OH) 的磁性 MAPTAC 基阳离子水凝胶（La(OH)@MMCH），作为一种潜在的吸附剂，用于增强从水环境中去除磷酸盐。La(OH)@MMCH 表现出 105.72±5.99 mg P/g 的高吸附容量，并且在 2 小时内达到平衡。La(OH)@MMCH 可以在 pH 值为 3.0 至 9.0 的宽范围内有效运行，并且在共存离子（包括 SO、Cl、NO、HCO、SiO 和 HA）存在下也能有效运行。吸附-解吸实验表明，La(OH)@MMCH 可以使用 NaOH-NaCl 作为解吸剂轻松再生，并且在经过五次循环后仍保留 73.3%的吸附容量。此外，La(OH)@MMCH 被用于处理磷酸盐浓度为 1.90 mg/L 的地表水，表现出高达 95.21%的去除效率。实际上，MMCH 在 pH 值为 3.0 至 11.0 的范围内表现出 34.38-59.38 meq/kg 的高表面电荷密度和 24 小时内 3014.57%的高溶胀比，表明 MMCH 可以产生增强的 Donnan 膜效应来预过滤磷酸盐。此外，La(OH)@MMCH 的双功能结构使其能够通过静电吸引和配体交换来捕获磷酸盐。所有结果均表明，La(OH)@MMCH 是一种用于富营养化控制和磷酸盐回收的有前途的吸附剂。
