高鐵酸鉀應用於重金屬去除之研究

Remove of Heavy Metal by ferrate (K2FeO4)

盧道詳(Dao-Xiang Lu)

指導教授 ： 羅煌木

朝陽科技大學/理工學院/環境工程與管理系/碩士(2013年)

摘要

摘要
高鐵酸鉀 (六價鐵) 具有高穩定性、強氧化能力及混凝作用，於處理污染物過程中高鐵酸鉀並不會產生任何誘變致癌的物質，且處理後所產生的副產物對環境較不會造成二次污染，故其為一種具氧化、吸附、混凝、助凝、殺菌及除臭功能為一體的新型綠色水處理藥劑。本研究主要以應用高鐵酸鉀去除重金屬並與零價鐵作比較及探討其於不同操作條件下之影響，另外也針對高鐵酸鉀去除BPA、氨氮、COD 作探討。
實驗結果顯示，(1) 高鐵酸鉀的去除率與其自身的穩定性有較密切的關係，當pH值 (pH 9) 於鹼性環境下，高鐵酸鉀其自身降解速率較慢，穩定性較佳，故可提供反應時間較長，故實驗於反應終時可達94%，此外，溫度也與高鐵酸鉀之降解率有關，當高鐵酸鉀於高溫 (60℃) 環境下，會產生劇烈的解離反應，進而影響其對於污染物的去除率，故調控溫度及pH值為影響高鐵酸鉀對於污染物其去除率的一大因素，另外，高鐵酸鉀與污染物之間的分子碰撞也與去除率有相關，當污染物初始濃度較高 (100 mg/L) 或高鐵酸鉀之加藥量較低(0.5 mg/L)時，皆會影響分子間接觸的機率，進而影響高鐵酸鉀與污染物反應的成效，於本實驗中，於反應終時其去除率分別為24% 及 12%。(2) 研究中另針對高鐵酸鉀處理污染物 : 重金屬、BPA，COD 及氨氮作探討，研究數據顯示，高鐵酸鉀對於重金屬、BPA，COD 及氨氮皆有不錯的效果92%、84% 及 72%，但發現高鐵酸鉀對於溶解性COD其去除效果較差，這可能是因為對於COD主要去除途徑為混凝作用，故對於溶解性COD而言，其去除效果較差。(3) 研究中，將高鐵酸鉀與零價鐵作比較，研究中發現，高鐵酸鉀對於8種金屬皆有不錯的去除效果Cu 79%、Hg 92%、Cd 87%、As 83%、Ni 82%、Cr 79%、Zn 67%、Pb 49%，反觀，奈米零價鐵對於部分金屬去除率較差，故高鐵酸鉀較適合應用於重金屬污染之去除。

關鍵字

化學需氧量 ； 雙酚A ； 重金屬 ； 零價鐵 ； 高鐵酸鉀 ； 氨氮 ； 混凝

並列摘要

Abstract
Potassium ferrate (VI) has high stability, strong oxidizing and coagulation ability. It will not generate any mutagenic carcinogens in the process of pollutants treatment. Besides, by-product generated after pollutants treatment will not cause secondary pollution to the environment. So, it is a kind of green water treatment agent with the novel properties of oxidization, absorption, coagulation, disinfection and deodorization. In this study, it is mainly to apply potassium ferrate for heavy metal removal, compare with Fe0 and investigate its influence under different operation conditions. In addition, removal of BPA, ammonia nitrogen and COD by potassium ferrate is also investigated.
The experimental result showed that the removal efficiency of potassium ferrate has closer relationship to its own stability. As pH value (pH 9) was in alkaline environment, the degradation rate of potassium ferrate was slower but with better stability. The reaction time was also found longer and in the end of the reaction, it could reach 94% removal efficiency. Furthermore, the temperature was also related to the degradation rate of potassium ferrate. When potassium ferrate was under high temperature (60℃), it will generate severe dissociation that will affect removal efficiency on pollutant, hence, to regulate temperature and pH value was a major factor that might affect the removal efficiency. Moreover, the molecular collision between potassium ferrate and pollutants was also related to the removal efficiency. As initial concentration of pollutants was higher (100 mg/L) or the addition dosage of potassium ferrate was lower (0.5 mg/L), they would affect the contact rates among molecules and further affected the reaction between potassium ferrate and pollutants. In this experiment, the removal efficiency was 24% and 12% respectively in the end ofthe reaction. Heavy metal, BPA, COD and ammonia nitrogen removal was also investigated. The data in the study showed, with regard to heavy metal, BPA, COD and ammonia nitrogen, potassium ferrate all had good removal efficiency reaching 92%、84% and 72% respectively. However, we found that the removal efficiency of soluble COD by potassium ferrate was not high. This was probably because that the removal mechanism of COD was mainly via coagulation. Comparing metals removal efficiency by potassium ferrate and Fe0, potassium ferrate was found better than Fe0 reaching Cu 79%, Hg 92%, Cd 87%, As 83%, Ni 82%, Cr 79%, Zn 67% and Pb 49% respectively.

並列關鍵字

Bisphenol A ； Heavy metals ； Potassium ferrate ； Fe0 ； Chemical Oxygen Demand ； Ammonia ； Coagulation

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