Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/27587
標題: 利用層狀雙氫氧化物 (LiAl2(OH)6Cl•xH¬2O)自水中移除磷
Removal of phosphate from water using Li/Al layered double hydroxide
作者: 鄭佳怡
Cheng, Chia-Yi
關鍵字: sorption;吸附;anion exchange;phosphate;layered double hydroxide;eutrophication;離子交換;磷酸根離子;層狀雙氫氧化物;優養化
出版社: 土壤環境科學系所
摘要: 
Phosphorus has been recognized as one of the main nutrients that cause eutrophication in surface water, so many technologies have been developed for phosphate removal from water. Adsorption is one of the major strategies for removing contaminants from water. In order to provide a cost-effective method for phosphate removal, it is essential to have a sorbent that can effectively immobilize phosphate. In this study, the sorption of orthophosphates was investigated for LiAl2(OH)6Cl•xH2O (Li/Al-LDH) which has high surface area and high anion exchange capacity (~4.5 mmol g-1). Sorption experiments were conducted at pH 4.5 and 9.5, at which the predominant species of phosphate are H2PO4- and HPO42-, respectively.In addition, the influence of pH, ion strength and competition ions on phosphate sorption was also investigated. The results showed that phosphates were sorbed by Li/Al LDH mainly through anion exchange at pH 4.5 and 9.5; under acidic condition (pH 4.5), the formations of surface complexes or surface precipitation of phosphate were also revealed by the results of 31P NMR. Competing anions strongly affected the adsorption behavior of phosphate with phosphate adsorption decreasing in the order: SO42->Cl- >Br->NO3- at pH 4.5. However, monovalent competing anions (Cl-、NO3- and Br-) had less influence on phosphate adsorption at pH 9.5.

人類經濟與休閒活動,產生了許多含磷的廢水,這些廢水被排放至表面水體將造成藻類過量增生,並進一步導致水體的優養化。對於水體中的磷的移除,吸附法為最有效的方法之ㄧ。本研究使用的鋰/鋁-層狀雙氫氧化物(Li/Al Layered double hydroxide, Li/Al LDH)由於具有很高的比表面積與陰離子吸附容量(~4.5 mmol g-1),具有去除環境中磷的潛力。在本研究中將探討水體中的環境因子,包括pH、離子強度與水體中其他競爭陰離子,對Li/Al LDH吸附磷的影響,並結合X光繞射、傅立葉轉換紅外光譜與固態磷-31核磁共振等儀器的輔助,了解Li/Al LDH與磷溶液反應過後其結構所產生的變化,並探討主要的吸附機制。結果發現,在pH 4.5與pH 9.5的環境下,都是以離子交換為主要的反應機制,但是在pH 4.5的環境下還有表面錯合和沉澱反應的發生。在pH 4.5的環境下,競爭離子的親和力大小為SO42->Cl- >Br->NO3-,但是在pH 9.5的環境下,除了SO42-對磷吸附有顯著的抑制外,其於單價競爭陰離子的影響程度皆較小。
URI: http://hdl.handle.net/11455/27587
Appears in Collections:土壤環境科學系

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