CAJ | 학술논문

利用双室微生物电化学装置对微生物和半导体矿物协同作用下偶氮类染料废水的还原脱色降解进行了系统的实验研究.不同光照条件及不同阴极电极材料的对比实验结果显示,偶氮染料甲基橙(MO)可作为终端电子受体直接从固体电极上获得电子被还原脱色;各对比实验中,在微生物催化与半导体矿物光催化协同作用条件下,MO还原脱色效率最高.电化学交流阻抗谱(EIS)的拟合结果显示金红石涂布阴极电极光照下极化内阻(Rp)为443.4 Ω,较无光条件下的1378 Ω显著降低,证明光照下金红石阴极的电子转移过程受其光催化作用的驱动.不同初始浓度下MO的生物-半导体催化还原反应符合准一级动力学模型,其反应速率随MO初始浓度降低而增加.通过对脱色产物的进一步分析,推测该实验中MO的还原脱色反应机制为: 阳极初始电子供体在微生物的催化作用下将电子通过阳极电极和外电路传递给阴极半导体矿物电极,进而在半导体矿物的光催化作用下通过光生电子还原终端电子受体MO,使MO中的偶氮键断裂,生成无色的联氨类衍生物.
이용쌍실미생물전화학장치대미생물화반도체광물협동작용하우담류염료폐수적환원탈색강해진행료계통적실험연구.불동광조조건급불동음겁전겁재료적대비실험결과현시,우담염료갑기등(MO)가작위종단전자수체직접종고체전겁상획득전자피환원탈색;각대비실험중,재미생물최화여반도체광물광최화협동작용조건하,MO환원탈색효솔최고.전화학교류조항보(EIS)적의합결과현시금홍석도포음겁전겁광조하겁화내조(Rp)위443.4 Ω,교무광조건하적1378 Ω현저강저,증명광조하금홍석음겁적전자전이과정수기광최화작용적구동.불동초시농도하MO적생물-반도체최화환원반응부합준일급동역학모형,기반응속솔수MO초시농도강저이증가.통과대탈색산물적진일보분석,추측해실험중MO적환원탈색반응궤제위: 양겁초시전자공체재미생물적최화작용하장전자통과양겁전겁화외전로전체급음겁반도체광물전겁,진이재반도체광물적광최화작용하통과광생전자환원종단전자수체MO,사MO중적우담건단렬,생성무색적련안류연생물.
The reductive decolorization of azo dye wastewater was investigated by using a dual-chambered bioelectrochemical cell e-quipped with different cathode materials (graphite and rutile-coated graphite). The experimental data show the feasibility of electricity generation by utilizing the model azo dye of methyl orange (MO) as the cathodic electron acceptor along with the color removal. Compared with MO reduction in traditional microbial fuel cell (MFC), an increase of the efficiency for MO reduction as well as the electricity production was successfully achieved in the irradiated rutile-cathode system. Quantification of the internal resistance by fitting the electrochemical impedance spectra (EIS) data to an equivalent circuit showed that the polarization resistance (R_p) of rutile-cathode significantly decreased from 1 378 Ω(dark control) to 443.4 (light control)Ω. The results demonstrate that the cathodic electron transfer process in the irradiated rutile-cathode system is driven by the photocatalysis of rutile. The photoreduction of MO at different initial concentrations obeys the pseudo-first-order kinetics, and the reaction constant increases with the decrease of the initial concentration of the dye. Based on an analysis of decolorization products, the authors put forward a possible cathodic reaction mechanism for the photoreductive decolorization of MO, i. e., the azo bond of MO is cleaved by photoelectrons at the irradiated rutile-cathode, resulting in the formation of colorless hydrazine derivative.