Application of amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite in fixed-bed column for phosphate removal from water
Atin Nuryadin, T. Imai
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引用次数: 5
Abstract
BACKGROUND AND OBJECTIVES: Fixed-bed column has been considered an industrially feasible technique for phosphate removal from water. Besides the adsorption capacity, the effectiveness of an adsorbent is also determined by its reusability efficiency. In this study, phosphate removal by a synthesized amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite in a fixed-bed column system was examined. METHODS: The effects of flow rate, bed height, phosphate concentration, solution pH, and adsorbent particle size on the phosphate adsorption ability were examined through a series of continuous adsorption experiments. The appropriate breakthrough curve models, phosphate adsorption from real anaerobic sludge and synthetic seawater, column regeneration and reusability, and adsorption mechanism were also investigated for practical application feasibility. FINDINGS: The results showed that the increased bed height and phosphate concentration, and reduced flow rate, pH, and adsorbent particle size were found to increase the column adsorption capacity. The optimum adsorption capacity of 25.15 mg-P/g was obtained at pH 4. The coexistence of seawater ions had a positive effect on the phosphate adsorption capacity of the composite. Nearly complete phosphate desorption, with a desorption efficiency of 91.7%, could be effectively achieved by 0.1 N NaOH for an hour. Moreover, the initial adsorption capacity was maintained at approximately 83% even after eight adsorption-desorption cycles, indicating that the composite is economically feasible. The high phosphate adsorption capacity of the composite involves three main adsorption mechanisms, which are electrostatic attraction, inner-sphere complexation, and anion exchange, where the amorphous zirconium hydr(oxide) on the surface of the layered double hydroxides likely increased the number of active binding sites and surface area for adsorption. CONCLUSION: The amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite, with its high adsorption capacity and superior reusability, has the potential to be utilized as an adsorbent for phosphorus removal in practical wastewater treatment. This study provides insights into the design of amorphous zirconium (hydr)oxide/MgFe layered double hydroxides composite for phosphorus removal and recovery in a practical system. ==========================================================================================COPYRIGHTS©2021 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.==========================================================================================
无定形氧化锆/MgFe层状双氢氧化物复合材料在固定床柱中的应用
背景和目的:固定床柱被认为是一种工业上可行的去除水中磷酸盐的技术。除吸附能力外,吸附剂的有效性还取决于其重复使用效率。在本研究中,研究了在固定床柱系统中合成的无定形氧化锆/MgFe层状双氢氧化物复合物对磷酸盐的去除。方法:通过一系列连续吸附实验,考察流速、床高、磷酸盐浓度、溶液pH和吸附剂粒度对磷酸盐吸附能力的影响。研究了合适的穿透曲线模型、真实厌氧污泥和合成海水对磷酸盐的吸附、柱再生和重复使用以及吸附机理,以确定实际应用的可行性。结果表明,床层高度和磷酸盐浓度的增加,流速、pH值和吸附剂粒度的减小,都会增加柱的吸附能力。在pH值为4时,最佳吸附量为25.15mg-P/g。海水离子的共存对复合材料的磷酸盐吸附能力有积极影响。0.1N NaOH作用1小时,可有效地实现近完全的磷酸盐解吸,解吸效率为91.7%。此外,即使在8次吸附-解吸循环后,初始吸附容量仍保持在约83%,表明该复合材料在经济上是可行的。复合材料的高磷酸盐吸附能力涉及三种主要的吸附机制,即静电吸引、内层络合和阴离子交换,其中层状双氢氧化物表面的无定形氢氧化锆可能增加了活性结合位点的数量和吸附表面积。结论:无定形氧化锆/MgFe层状双氢氧化物复合材料具有较高的吸附能力和良好的重复使用性能,具有在实际废水处理中用作除磷吸附剂的潜力。本研究为在实际系统中设计用于磷去除和回收的无定形氧化锆/MgFe层状双氢氧化物复合材料提供了见解==========================================================================================版权所有©2021作者。这是一篇根据知识共享署名(CC BY 4.0)条款分发的开放获取文章,该条款允许在任何媒体上不受限制地使用、分发和复制,只要引用了原始作者和来源。不需要作者或出版商的许可==========================================================================================
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