微波预处理污泥上清液为燃料的微生物燃料电池产电特性研究

Electricity Generation by the Microbial Fuel Cells Using the Supernatant Fluid of Microwave Pretreated Sludge as Fuel

采用经微波预处理的剩余污泥上清液作为接种体,成功地启动了空气阴极单室无膜微生物燃料电池(MFC),同时考察了不同微波时间和功率下MFC最大输出功率密度以及外接电阻对MFC的影响.结果表明,MFC整个产电周期长达600h,在同一微波功率(900W)下,MFC最大输出功率密度随辐射时间的延长而增大,在300s时达到210.07mW·m-2;当微波时间(300s)相同时,随着微波功率的增大,MFC最大输出功率在720W处出现一个峰值随后下降.长时间和较高功率(<900W)的微波处理能够有效地提高MFC的工作效率;在最佳微波处理条件(300s,720W)下,最大输出功率密度最高可达306.2mW·m-2;不同外接电阻(30、500、2000Ω)下,库仑效率依次为83.3%、79.0%、33.6%;通过扫描电镜观察到,当外接电阻较高(2000Ω)时,阳极表面附着的微生物以球菌为主,外接电阻较低(30Ω)时,形态较为复杂,主要是丝状菌、球菌和杆菌,表明外接电阻会对MFC库仑效率和阳极表面微生物的富集产生影响.

A single-chamber membrane-less microbial fuel cell（MFC） was successfully started up by using the filtrate of sludge pretreated by microwave as substrate.The effects of microwave power and time on the maximum output power density were investigated and the influences of external resistance on the performance of MFC were also analyzed.The results indicated that the electric cycle lasted for nearly 600 h.Under the same microwave power（900 W）,the maximum output power density ascend along with the radiation time,and was amount to 210.07 mW·m^-2 as the radiation time reached to 300 s.When radiation time kept constant（300 s）,the maximum output power density had a peak on the power of 720 W followed by a gradual decrease with the increase of microwave power.The performance of MFC could be effectively improved by the longer irradiation time and moderate higher microwave power（ 900 W）.On the optimal treatment conditions（300 s,720 W）,the maximum output power density could reach up to 306.2 mW·m^-2.When the external resistance was 30 Ω,500 Ω,2 000 Ω,the coulombic efficiency was 83.3%,79.0%,33.6% respectively.The SEM observation showed that the surface of anodic electrode was covered by spherical bacteria at higher external resistance of 2 000 Ω.As at lower external resistance of 30 Ω,it was covered by several other kinds of bacteria besides spherical bacteria,such as filamentous bacteria and bacilliform bacteria.The coulombic efficiency and microorganisms on the surface of anodic electrode were influenced by the external resistance.