MnO_2为阴极催化剂的微生物燃料电池处理淀粉废水研究

Starch Processing Wastewater Treatment Using a Continuous Microbial Fuel Cell with MnO_2 Cathodic Catalyst

以淀粉废水为接种液和基质,MnO2为阴极氧还原催化剂,构建双室连续流微生物燃料电池(MFC),通过在线监测MFC输出电压和分析废水相应指标等方法研究电池产电性能及废水处理效果(化学需氧量、氨氮).结果表明,与阴极未负载催化剂的MFC相比,阴极负载MnO2催化剂的MFC输出功率密度可提高约4.2倍,化学需氧量(COD)和氨氮(NH+4-N)去除率分别提高8.3%和7.0%.进一步优化实验表明,淀粉废水初始COD浓度、pH值及电导率等参数对电池产电和废水处理性能都有一定影响.其中,当淀粉废水COD浓度为2426.0mg/L、pH值为7.0且NaC l浓度达到2.0g/L时电池的性能最优.此时,最大输出功率密度为30.8W/m3,对应电流密度为121.0A/m3,COD和NH4+-N去除率分别为92.7%和86.5%.本试验利用廉价MnO2为催化剂,显著提高了MFC处理淀粉废水和产电的效果,并有利于MFC的工程化应用.

This study constructed a tubular two-chamber microbial fuel cell(MFC) using MnO2 as cathodic catalyst for treating starch processing wastewater under a continuous-flow mode.The MFC performance of power generation and wastewater treatment was evaluated by measuring the voltage output,removal efficiencies of chemical oxygen demand(COD) and ammonium-nitrogen(NH+4-N).Compared with the MFC without MnO2 loading,the maximum power density of the MnO2-catalyzed MFC was increased by 4.2 times,and the removals of COD and NH+4-N were enhanced by 8.3% and 7.0%,respectively.The effects of initial COD concentration,pH and conductivity on the MFC performance were further studied for optimization.The results showed that the optimum conditions for MFC operation were:initial COD concentration of 2426.0mg/L,pH of 7.0,and NaCl concentration of 2.0g/L.Under the optimum condition,the MFC approached a maximum power density of 30.8W/m3 at a current density of 121.0A/m3,and the highest COD removal of 92.7% and NH+4-N removal of 86.5%.The study suggested that the inexpensive catalyst of MnO2 is very promising for MFC application as an approach to simultaneous power generation and wastewater treatment.