| 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. |
