Study On Treating Chromium Wasterwater In Porous Medium Microbial Fuel Cell

This paper introduced the development of Microbial Fuel Cell (MFC),principal and the latest research process.A tow-chamber porous medium MFC wasestablished to treat chromium wastewater.The effects of Cr (VI) removal andelectricity generation were investigated.Factors about open and closed circuit, CODconcentration, Cr (VI) concentration, pH of catholyte, external resistance, ambienttemperature, and so on.On the basis of this MFC, a MFC with phenol as the anodesubstrate had been successfully constructed.The effects of Cr (VI) and phenolremoval and electricity generation were investigated.Factors about open and closedcircuit, kind of anode substrate, phenol concentration.The experiment was to studymechanism and the optimum operating condition of treating Cr (VI) wastewater. Atthe same time, the experiment was to explore the feasibility of its application insitu bioremediation of Cr (VI) wastewater in the groundwater environment.Themain conclusions are as follows:1. In closed circuit, the degradation rate of Cr (VI) was increased20.7%, the averagereduction rate was increased0.12mg·L-1·h-1, the removal rate of COD was slightly higherthan that in open circuit. It explained that electrochemical system had promoting effect inthe degradation of Cr (VI) and COD. It is feasible to use MFC to treat Cr (VI) wastewater.2. The tow-chamber MFC can treat Cr (VI) wastewater at the cathode, and the outputvoltage can be obtained simultaneously. Through a series of experiments, the best operatingconditions of this MFC can be obtained. It is1000mg/L COD(initial anode concentration),pH=2(catholyte),1000(external resistance),25℃(ambient temperature).3. Through treating simulated Cr (VI) wastewater, it concluded that the MFC can beoperated steady in ambient temperature of groundwater. But the higher treatment effect andelectricity generation can be obtained when the catholyte was high concentration acidic Cr(VI) wastewater. So in actual application, this MFC is more suitable for the treatment ofacidic Cr (VI) wastewater in relatively high concentrations.4. In closed circuit, the removal rates of Cr (VI) and phenol were increased by20.3%and20.3%respectively. It explained that electrochemical system can promote thedegradation of phenol. So it is feasible to use MFC to treat Cr (VI) and phenol wastewatersimultaneously.5. With419mg/L phenol as carbon source, MFC can obtain continuous electricity production. Within168h, the maximum output voltage was205mV. It proved that thisMFC can treat phenol wastewater and obtain output voltage meanwhile. But the outputvoltage was much lower than the same condition with sodium acetate as carbon source. Itexplained that the production performance of the MFC which used single easily degradablematerials as carbon source. So it needs further research to promote the productionperformance of this MFC.The research results showed that using porous medium microbial fuel cell totreat Cr (VI) and phenol wastewater is feasible. MFC can degradate Cr (VI) and phenol,and obtain the output voltage. As a new type of MFC, porous medium microbial fuel cellshave good prospects and development potential in situ repairmen of the groundwaterpollution.