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A chemical absorption−biofilm electrode reactor (CABER) integrated system was used for removal of nitrogen monoxide (NO) from flue gas. Effects of the electric current on NO removal efficiency, concentration of Fe(II)EDTA, and consumption rate of glucose in the stabilization phase were investigated. Results indicate that the optimum impressed current was 0.04 A [i.e., 66.7 A m −3 net cathodic compartment (NCC) of the current density]. Under this condition, the consumption rate of glucose was 0.462 g h −1 . Performance evaluation of this new approach was investigated under optimum conditions as well. It is noted that minimum residence time was only 20 s, maximum oxygen tolerability was 10%, and maximum elimination capacity of NO was 104.2 g of NO m −3 h −1 . The contribution of H 2 and glucose in reduction of Fe(III)EDTA was also studied. The results indicated that increasing the H 2 supply appropriately could reduce the consumption of glucose. This new approach showed a better performance on NO removal and a larger processing load than those of the chemical absorption−biological reduction (CABR) integrated system.

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A promising technique called chemical absorption-biological reduction (CABR) integrated approach has been developed recently for the nitrogen oxides (NO(x)) removal from flue gases. The major challenge for this approach is how to enhance the rate of the biological reduction step. To tackle the challenge, a three-dimensional biofilm-electrode reactor (3D-BER) was utilized. This reactor provides not only considerable amount of sites for biofilm, but also many electron donors for bioreduction. Factors affecting the performance of 3D-BER were optimized, including material of the third electrode (graphite), glucose concentration (1000 mg·L(-1)), and volume current density (30.53 A·m(-3) NCC). Experimental results clearly demonstrated that this method significantly promotes the bioreduction rate of Fe(II)EDTA-NO (0.313 mmol·L(-1)·h(-1)) and Fe(III)EDTA (0.564 mmol·L(-1)·h(-1)) simultaneously. Experiments on the mechanism showed that Fe(II)EDTA serves as the primary electron donor in the reduction of Fe(II)EDTA-NO, whereas the reduction of Fe(III)EDTA took advantage of both glucose and electrolysis-generated H(2) as electron donors. High concentration of Fe(II)EDTA-NO or Fe(III)EDTA interferes the bioreduction of the other one. The proposed methodology shows a promising prospect for NO(x) removal from flue gas.