Decolorization Of Azo Dye In A Bioelectrochemical Systemlmproved

Bioelectrochemical systems (BESs) including microbial fuel cells (MFCs) andmicrobial electrolysis cells (MECs), integrate three important wastewater treatmentoptions, namely, biological treatment, electrolytic dissociation and electrochemicaloxidation/reduction, and are regarded as a new sustainable and effective strategy fortreatment of these wastes.In this study, we have worked on three types bioelectrochemical system: cathodicdecolorization of MO, heterogeneous Bioelectrochemical Fenton system, thesingle-chamber bioelectrochemical system. Aimed to explore feasibiliaty of thedecolorization of MO and the MO decolorization efficiency was significantlyenhanced, when the BES was supplied with power.BES have emerged as a potentially interesting technology for wastewatertreatment with energy generation or save energy. Results suggested that we exploredthe use of a BES to abiotic cathodic decolorization of a model azo dye, methyl orange(MO), where the process was driven by microbial oxidation of glucose at the anode.The MO decolorization efficiency reached78.85%within10h and96.76%within25hours, with concomitant energy recovery. The maximum power density was3.403W/m~3, when MO concentration was100mg/L. The MO decolorization efficiency wassignificantly enhanced when the BES was supplied with power, reaching92.2%within10h, the BES had a low energy consumption of0.879kWh/molMO at acontrolled applied voltage0.7V.We used two types heterogeneous BES-Fenton:one is FeOOH added to cathodiccompartment,the other is the air cathode with FeOOH composite cathode. Weexplored the use of a heterogeneous BES-Fenton with FeOOH added to cathodiccompartment. The MO decolorization efficiency reached84.77%within10h, withconcomitant energy recovery. The maximum power density was3.96W/m~3, whenMO concentration was25mg/L. With the same conditions, the air cathode withFeOOH composite cathode. The MO decolorization rate was84.77%and themaximum power density was5.15W/m~3. The MO decolorization efficiency wassignificantly enhanced when the BES was supplied with power, reaching96.6% within10h.The experiment of single-chamber air-cathode BES suggested that when MOconcentration was100mg/L and the glucose concentration was2g/L, the MOdecolorization efficiency reached94.74%within6h, and the maximum power densitywas11.78W/m~3. When the glucose concentration was0g/L,the MO decolorizationefficiency reached86.72%within9h，and the maximum power density was6.56W/m~3,the average current density was13.82A/m~3. Results demonstrated that Add theglucose is helpful to the degradation.Results demonstrated that three types BES can generate electricity while treatingMO wastewater. With the same conditions, The order of decolorization rate of MO isthe single-chamber air-cathode BES>the heterogeneous BES-Fenton with the aircathode with FeOOH composite cathode> Cathode decolorazation BES. The MOdecolorization efficiency was significantly enhanced when the BES was supplied withpower.