微生物燃料电池对去除稻田硫离子的影响

Removal of Sulfide in the Rice Field Using Microbial Fuel Cells

在模拟水稻田中构建微生物燃料电池(Microbial fuel cells,MFCs)并设置对照组,研究MFCs运行对水稻田的水和土壤中S2-浓度、pH、ORP(Oxidation-reduction potential,氧化还原电位)以及水稻生长情况的影响。结果表明,水稻种植期间,稻田MFCs的水和土壤(深2.5mm和5.0mm)中S2-浓度分别为(4.70±1.51)mg·L-1、(6.97±1.36)mg·L-1和(8.33±1.76)mg·L-1,在对照组相应各层中S2-浓度为(7.77±1.99)mg·L-1、(12.9±3.06)mg·L-1和(16.5±4.63)mg·L-1。稻田MFCs的水和土壤(深2.5mm和5.0mm)中的ORP值分别为(106±7.7)mV、(-142±30)mV和(-209±9)mV,在对照组相应各层中的ORP分别为(119±11.5)mV、(-209±9)mV和(-386±2)mV。稻田MFCs和对照组中水稻干重分别为(0.548±0.005)g和(0.442±0.003)g。在水稻田中构建MFCs可以降低水和各土壤层中S2-浓度,增高各土壤层中ORP值,且能明显促进水稻的生长。

We develop the rice microbial fuel cells（MFCs） in a lab-scale rice field and control reactors to evaluate the effect of MFCs on the sulfide concentration, pH, oxidation-reduction potential（ORP） in water and soil as well as the growth of rice. During the rice growing period the sulfide concentrations in water, 2.5 mm soil layer, 5.0 mm soil layer in the rice field with MFCs are（4.70±1.51）mg·L ^-1,（6.97±1.36）mg·L ^-1 and（8.33±1.76）mg·L ^-1 respectively, the sulfide concentrations in control reactors are（7.77±1.99）mg·L ^-1,（12.9±3.06）mg·L ^-1 and（16.5±4.63）mg·L ^-1 respectively. The ORP values in water, 2.5 mm soil layer, 5.0 mm soil layer in the rice field with MFCs are（106±7.7）mV,（-142±30）mV and（-209±9）mV. The ORP values in control reactors are（119±11.5）mV,（-209±9）mV and（-386±2）mV respectively. The dry weights of rice in MFCs and control reactors are（0.548±0.005）g and（0.442±0.003）g respectively. The results show that the sulfide concentrations are lower and the ORP values are higher in the water and soil of the rice MFCs than that of the control reactors. The dry weights of rice in the rice MFCs are much higher than that in control reactors. It illustrates that sulfide is oxidized in the anode of the rice MFCs and that the growth of rice is promoted in the lab-scale rice fields.