本文選題：電化學(xué)還原　切入點：吸附　出處：《湖南大學(xué)》2015年碩士論文

【摘要】：電化學(xué)還原技術(shù)通常依靠電極電子得失發(fā)揮還原作用,該技術(shù)無需添加額外還原試劑、污泥產(chǎn)量相對較少的潔凈處理過程使其對生態(tài)環(huán)境的影響較小,因而已逐漸發(fā)展成為具有強大競爭力和應(yīng)用前景的水處理方法之一。電化學(xué)還原技術(shù)也可應(yīng)用于含Cr(Ⅵ)廢水的處理過程,但其還原過程較慢的反應(yīng)動力響應(yīng)、較高的電流效率和能耗問題等均大大限制了該方法在廢水處理方面的實際應(yīng)用和推廣。因此,采取有效手段在Cr(Ⅵ)的電化學(xué)還原過程中提高其相應(yīng)的還原動力學(xué)反應(yīng)速率以改善上述問題至關(guān)重要。本研究以通過電化學(xué)聚合法制備的硫酸-甘氨酸共摻雜聚苯胺修飾的網(wǎng)狀玻璃碳(RVC/PANI-SA-GLY)電極作為電解槽陰極,成功構(gòu)建了一個新穎的吸附-電化學(xué)還原體系以加快Cr(Ⅵ)的去除過程。本研究首先通過響應(yīng)面法探尋了新型摻雜劑甘氨酸存在條件下的最優(yōu)化聚苯胺聚合條件組成;之后在以硫酸摻雜聚苯胺修飾的網(wǎng)狀玻璃碳(RVC/PANI-SA)電極、RVC電極為對比實驗組的基礎(chǔ)上,探究了電勢、Cr(Ⅵ)初始濃度、初始p H和電流密度對RVC/PANI-SA-GLY電極電化學(xué)還原Cr(Ⅵ)過程的影響規(guī)律;通過傅里葉紅外光譜及能譜分析技術(shù)對RVC/PANI-SA-GLY電極去除Cr(Ⅵ)的吸附-還原機理進行了驗證和闡述;最后本研究對RVC/PANI-SA-GLY電極的電化學(xué)穩(wěn)定性及可循環(huán)利用性能進行了評估。實驗結(jié)果表明:最優(yōu)化劑量甘氨酸的加入不僅能最大程度提高共摻雜聚苯胺的電化學(xué)聚合速度,同時在理論及實際過程中均一定程度上實現(xiàn)了甘氨酸對Cr(Ⅵ)陰離子吸附作用的最大化利用而提高了Cr(Ⅵ)的最終去除效率,CCD優(yōu)化設(shè)計獲得的最優(yōu)化聚合條件為苯胺、硫酸、甘氨酸濃度分別為0.2 mol/L、0.85mol/L、0.93 mol/L;RVC/PANI-SA-GLY電極在Cr(Ⅵ)的電化學(xué)還原過程中展現(xiàn)出比RVC/PANI-SA電極和RVC電極更快的還原反應(yīng)速率,而在與RVC/PANI-SA電極相比時RVC/PANI-SA-GLY電極上所摻雜甘氨酸的吸附作用更得以凸顯,該作用對Cr(Ⅵ)去除效率的提高在更負電勢、較低Cr(Ⅵ)初始濃度(5 mg/L、10mg/L)、非極酸溶液中(初始p H=2、3)及更高電流密度條件下尤為明顯,最佳情況下(E=-0.8 V,C0=10 mg/L,p H=2,t=900 s)可取得高出RVC/PANI-SA電極7.84%的Cr(Ⅵ)去除效率并實現(xiàn)廢水中Cr(Ⅵ)的完全去除;在較負的應(yīng)用電勢下(-0.6 V、-0.8 V),RVC/PANI-SA-GLY電極可相對大幅地提高Cr(Ⅵ)電化學(xué)還原過程的電流效率;傅里葉紅外光譜及能譜分析結(jié)果揭示了RVC/PANI-SA-GLY電極潛在的吸附-還原機理,該機理可能與電極上甘氨酸質(zhì)子化的氨基集團對HCrO_4~-的吸附作用有關(guān),是導(dǎo)致更快還原反應(yīng)速率產(chǎn)生的主要原因;RVC/PANI-SA-GLY電極的電化學(xué)穩(wěn)定性相對令人滿意,將其進行重復(fù)利用具有較高的可行性。RVC/PANI-SA-GLY電極處理廢水過程的治理時間短、電流效率高等優(yōu)勢使其在含Cr(Ⅵ)廢水尤其是低濃度含Cr(Ⅵ)廢水處理方面具有良好的應(yīng)用前景,是一種極具潛力的新型修飾電極。
[Abstract]:Electrochemical reduction techniques usually rely on electronic gain reduction electrode play, the technology without the need to add additional reagents, clean process less sludge production because of its smaller impact on the ecological environment, which has gradually become one of the water treatment method has strong competitiveness and application prospect. The electrochemical reduction technology can also be applied to Cr (VI) treatment process of wastewater, but the reaction dynamic process of slow response, application and promotion of high current efficiency and energy consumption are greatly limits the method in wastewater treatment. Therefore, taking effective measures in the Cr (VI) to improve the corresponding reduction reaction rate to improve the above problems is the electrochemical reduction process. In this study, through the mesh glass prepared by electrochemical polymerization sulfuric acid doped polyaniline modified glycine Carbon (RVC/PANI-SA-GLY) electrode as cathode, successfully constructed a novel adsorption electrochemical reduction system to speed up the process of removing Cr (VI). In this study, through the response surface method explores new doping agent under the condition of the existence of glycine optimization of polyaniline polymerization condition; after the reticulated vitreous carbon doped sulfate polyaniline modified electrode (RVC/PANI-SA), RVC based electrode as the comparison group, to explore the potential of Cr (VI) initial concentration, the initial P H and current density on the reduction of Cr (VI) RVC/PANI-SA-GLY electrode electrochemical process were studied by spectral analysis; the removal of Cr on RVC/PANI-SA-GLY electrode technique and Fourier transform infrared spectroscopy (to VI) reduction mechanism of adsorption was verified and discussed; finally the electrochemical stability of RVC/PANI-SA-GLY electrode and recycling performance was evaluated. The experimental results Show that the optimization can not only improve the total dose of glycine doped polyaniline electrochemical polymerization velocity maximum, while achieving a glycine on Cr in the theory and practical process are to a certain extent (VI) increased Cr maximum use of anion adsorption (VI) the final removal efficiency of CCD, optimization design for the polymerization conditions for aniline, sulfuric acid, glycine concentration were 0.2 mol/L, 0.93 0.85mol/L, mol/L; RVC/PANI-SA-GLY electrode in Cr (VI) show a faster reaction rate than the RVC/PANI-SA and RVC electrodes on the electrochemical reduction process, and the adsorption of RVC/PANI-SA-GLY in comparison with RVC/PANI-SA electrode electrode doped glycine is more prominent and the effect on Cr (VI) removal efficiency in a more negative potential, low initial concentration of Cr (VI) (5 mg/L, 10mg/L), non polar acid solution (initial P H=2, 3) and higher current density condition is particularly evident, the best condition (E=-0.8 V, C0=10 mg/L, P H=2, t=900 s) can achieve higher RVC/PANI-SA 7.84% electrode Cr (VI) and the removal efficiency of Cr in wastewater (VI) were completely removed; in the application of potential more negative (under -0.6 V -0.8, V, Cr) RVC/PANI-SA-GLY electrode can improve the relative greatly (VI) the current efficiency of electrochemical reduction process; spectrum analysis results reveal the mechanism of reduction of adsorption and RVC/PANI-SA-GLY electrode potential and Fourier transform infrared spectroscopy, the mechanism may be related to the adsorption on the electrode and the amino group of glycine proton HCrO_4~-, is the leading the reason for the faster reaction rate generated; electrochemical stability of RVC/PANI-SA-GLY electrode is relatively satisfactory, the repeated use of.RVC/PANI-SA-GLY has the high feasibility of wastewater treatment process of electrode treatment time is short, electric The advantages of high flow efficiency make it have good application prospects in the treatment of wastewater containing Cr (VI), especially low concentration of Cr (VI), and it is a potential new modified electrode.

【學(xué)位授予單位】：湖南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X703

【參考文獻】

相關(guān)期刊論文 前4條

1 李莉娜;董廣霞;唐桂剛;景立新;王業(yè)耀;;中國含六價鉻工業(yè)廢水排放的行業(yè)貢獻與空間分布特征分析[J];環(huán)境污染與防治;2013年12期

2 謝翼飛;李旭東;李福德;;生物硫鐵復(fù)合材料處理含鉻廢水及鉻資源化研究[J];中國環(huán)境科學(xué);2009年12期

3 求淵;施勇琪;張相陽;李德勝;況武;;脈沖電絮凝處理電鍍含鉻廢水的實驗研究[J];環(huán)境工程學(xué)報;2009年06期

4 瞿建國,申如香,徐伯興,李福德;微生物法處理含鉻(Ⅵ)廢水的研究[J];化工環(huán)保;2005年01期

相關(guān)博士學(xué)位論文 前1條

1 徐衛(wèi)華;微生物還原Cr（Ⅵ）的特性與機理研究[D];湖南大學(xué);2007年

相關(guān)碩士學(xué)位論文 前2條

1 陳超;二氧化鈦/石墨烯復(fù)合物的制備及其高效光催化還原Cr(VI)的研究[D];華中科技大學(xué);2011年

2 劉恢;改性活性污泥處理含鉻廢水的研究[D];中南大學(xué);2004年

，

本文編號：1676041