- 學位論文
以氫氧化鑭改質磁鐵除磷
Phosphate removal performance of magnetic Carbon-shelled Magnetite functionalized with Lanthanum (MFC@La(OH)3)
摘要
磷酸鹽是以PO43-的形式存在於自然界中，而且它是地球上所有已知生命的關鍵元素以及它是由核酸與三磷酸腺苷(ATP)所組成。磷酸鹽在人的日常生活中也得到了廣泛的應用，以目前蓬勃發展的人口階段中，磷酸鹽主要用於製成肥料(磷肥)，目的為增加所需作物和糧食的數量。由於磷酸鹽受到大量的使用，因此磷酸鹽時常被人們排入水中，因此必須能夠快速處理磷酸鹽的方法。吸附作用被認為是去除磷酸鹽最合適的方法，另一種方式則是採用Fe3O4，主要是因為其具有磁性、低毒性及經濟性的合成方法。在此研究中，已經成功的製作了將具有氫氧化鋼magnetic Fe3O4 Carbon-shell (MFC)官能基摻入鑭中做為奈米複合材料。奈米複合材料早已被證明相容於擬二階化學動力學模式Pseudo-second-order kinetic model以及Freundlich等溫吸附模型，因此表示各式各樣表層具有多線性吸附機制。通過各種實驗後，該材料具有30.85mg P/g的高吸附能力，可以去除89％的磷酸鹽，其效率僅以13％的達到watermelon Biochar的性能，最大吸附量為1.1 mg P/g。此外，MFC@La(OH)3在連續5次的使用和再生過程中也表現出了穩定的可再用性，儘管去除效率緩慢降低至48％。此材料在鹼性環境下連續使用5次後依然呈現穩定的狀態。
並列摘要
Phosphate naturally exists in form of PO43-, is a crucial element for all known forms of life on Earth with enormous application in humans daily, where it mostly being utilized for Phosphate fertilizer, where possible run-off to the aquatic environment is no longer a fresh finding. Adsorption had been considered to be the best and most suitable method when it comes to Phosphate removal, and Fe3O4 is a potential candidate for its natural magnetism, low toxicity and economic synthesis procedure. In this study, magnetic Fe3O4 Carbon-shell (MFC) functionalization with Lanthanum had been successfully produced with various weight ratio between Fe and La utilizing facile procedure and is compared with another well-known adsorbent, which is Biochar derived from watermelon. The nano-composite is proven to be Pseudo-second-order kinetic model and Freundlich isotherm model compatible, thus indicating its heterogeneous surface layer with multi-linearity adsorption mechanism. 89% of Phosphate can be removed thanks to its high adsorption capacity of 30.85 mg P/g, which is superior to the performance of watermelon Biochar at only nearly 13% efficiency with 1.1 mg P/g maximum capacity. Moreover, MFC@La(OH)3 had also expressed its stable reusability throughout 5 continuously usages and regeneration, albeit slowly decrease in removal efficiency to 48%.