The Technology On Remediation Of Nitrate Pollution In Groundwater By Using Fuel Cells

In this paper,it introduced the source,harm and treatment methods of nitratepollution in Groundwater. It introduced the mechanism of fuel cell and the latestresearch process,too.On this basis,according to the results of small trial,thetwo-chambered non-biological steel fuel cells （SFC） and microbial fuel cell （MFC）of pilot tests were constructed with continuous inflow and outflow, to repair thesimulation of nitrate pollution of groundwater.Constructed the small trial of MFC and SFC,studies the influence ofelimination effect about various variables （Cathode material, different pH of thecathode chamber, different nitrate concentrations and add microbe in the cathodechamber and so on）. The results show that:（1） These small trial of SFC/MFC divices can promote the denitrificationreaction effectively were verified.The SFC and MFC’s degeneration efficiency tonitrate were equally62.0%and67.04%, the average degeneration speed of nitrate is6.58mgNO₃^-/L d and7.11mgNO₃^-/L d approximately.（2） Chemical PbO₂deposition on stainless steel plate as cathode material ismore beneficial than stainless steel plate and ordinary carbon cloth to thedegradation of nitrate.A appropriate concentration of nitrate solution which close toneutral is more favorable for the degradation of nitrate, and adding microbial to thecathode chamber can improve the degradation greatly.（3） The output voltage of SFC/MFC divices was related to the degradation rateof cathode chamber, the higher the output voltage, the faster the degradation rateof nitrate.According to the results of small trial,the pilot tests of SFC and MFC wereconstructed with continuous inflow and outflow.The results show that:（1） At room temperature,the pilot tests of SFC and MFC’s removal efficienciesfor nitrate were89.58%and65.46%respectively, the average degradation rate ofnitrate is about11.036mgNO₃^-/L d and6.337mg NO₃^-/L d respectively. It indicatedthat SFC/MFC is a highly effective way to remove nitrate.（2） At room temperature,the pilot tests of MFC had the effective removalefficiencies for COD_Crand TOC. The removal efficiencies of MFC for COD_CrandTOC were higher than the anaerobic control device about26%and21%respectively. （3） The hydraulic retention time of MFC were30days and60daysrespectively, and the nitrite degradation rate were65.46%and74.87%respectively.It showed that the longer hydraulic retention time is helpful todegradation of nitrate.In this paper, the results show that SFC and MFC can be designed to enhanceddenitrification for nitrate pollution in groundwater, and can output power at thesame time. As a new technology of in-situ remediation for nitrate pollution,SFC/MFC have the great potential for the development and application.