Cu2+对微生物燃料电池产电性能的影响及其迁移转化过程

Effect of Cu^(2+) on the Electricity Generation and Its Transformation Process in Anode of Microbial Fuel Cells

探讨了微生物燃料电池阳极中Cu^(2+)对其产电性能的影响以及Cu^(2+)的迁移转化过程。微生物燃料电池的阳极中加入质量浓度为5.54~88.64mg/L的Cu^(2+),使其最大功率密度增加到536.6mW/m2,此时Cu^(2+)去除率大于95%。大部分的Cu^(2+)(89.24%)被生物膜吸附或还原,6.15%的Cu^(2+)沉积在阳极室底部,3.12%的Cu^(2+)附着在石墨阳极表面,只有极少量Cu^(2+)(小于0.1%)迁移到了阴极,Cu^(2+)对微生物燃料电池的最低致毒质量浓度为22.16 mg/L。通过SEMEDS和XPS分析得出大部分Cu^(2+)(63.56%)在微生物燃料电池的生物膜表面被还原为Cu^+和Cu^0。这一发现将为去除和回收有机废水中的重金属提供新的思路。

The proper concentration of metal ions in anode of microbial fuel cells(MFCs)could promote the growth of microbes and increase the power generation ability.In order to understand the effect of Cu 2+in anode of MFC,the effects of Cu 2+concentration in anode on MFC operation,the removal capacity of Cu 2+,and the migration and transformation of Cu 2+were studied.The species and valence states of the material produced on the surface of the microorganism in anode of MFCs were also systematically analyzed.The migration and transformation of Cu 2+and its effect on electricity generation performance were investigated in anode of MFCs.The results showed that the maximum power density increased to 536.6 mW/m 2 by adding Cu 2+(5.54-88.64 mg/L)in anode of MFC.The removal rate of Cu 2+was more than 95%by adding Cu 2+(5.54-88.64 mg/L)in anode of MFCs.Most of the Cu 2+(89.24%)was adsorbed or reduced by biofilm,while 6.15%Cu 2+was deposited in the anode chamber bottom,3.12%Cu 2+was attached on the surface of the graphite anode,and only a very small amount of Cu 2+(less than 0.1%)was migrated to the cathode.The minimum toxic concentration(MTC)of Cu 2+for MFCs was 22.16 mg/L.The scanning electron microscope-energy dispersive spectrometer(SEM-EDS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)analysis showed that most of Cu 2+(63.56%)was reduced to Cu+and Cu 0 on the surface of biofilm in anode of MFCs.This discovery will provide a new concept for the removal and recovery of heavy metals from organic wastewater by MFCs.