OPTIMAL ELECTRON DONOR SUPPLY PLAN FOR Fe(III)EDTA REDUCTION IN A CHEMICAL ADSORPTION-BIOFILM ELECTRODE REACTOR INTEGRATED SYSTEM FOR NOx REMOVAL

Both glucose and cathodes can be used as electron donor for Fe(III)EDTA reduction in a chemical adsorption-biofilm electrode reactor (CABER) integrated system. Moreover, glucose can also serve as organic carbon source and cathodes can provide carbon source through hydrogen autotrophy. Therefore, the interactions between these two electron donors is of great importance for improving NO x removal efficiency and optimizing power consumption. The results experimentally and kinetically confirmed that cathode electrons are the more efficient electron donor for Fe(III)EDTA reduction. However, glucose can inhibit hydrogen autotrophy and maximize utilization efficiency of cathode electrons. For example, under 0.04 A of impressed current, the Fe(III)EDTA reduction rate contributed by cathode electrons increased from 0.89 to 1.5 mmol h(-1) with the increase of glucose dosage from 0 to 50 mg L-1. And excess glucose provides little contribution for the Fe(III)EDTA reduction rate. The predicted model well described the experimental results and revealed that 0.06 A and 200 mg L-1 glucose was the optimal electron donor supply plan for Fe(III)EDTA reduction in the tested BER.