title: Nitrate reduction with biotic and abiotic cathodes at various cell voltages in bioelectrochemical denitrification system.
abstract: Electrochemical treatment of nitrate ions was attempted using different catalysts on the cathode in bioelectrochemical denitrification systems. The carbon cathode coated by biofilm (biocathode) could remove 91 % of nitrate ions at 1.0 V, which was almost same as the Pt-coated electrode (90 %). The exchange current density of biocathode was 0.0083 A/m(2), which was almost 22 times higher than with an abiotic plain carbon cathode. The formation of intermediate products in nitrate reduction varied depending on the cell voltage. At 0.5 V, a large portion of nitrate was converted to ammonia, but at more increased cell voltage (0.7 and 1 V) a high amount of nitrite ions was found with little ammonia formation in cathodic solution. The maximum nitrate removal rate was 0.204 mg NO(3)-N/cm(2)d by biocathode, while plain carbon paper showed only 0.176 mg NO(3)-N/cm(2)d. Electrochemical analysis of chronoamperometry showed a higher stable current generation for biocathode (3.1 mA) and Pt-coated cathode (2.8 mA) as compared to plain carbon (0.6 mA) at 0.7 V of poised voltage.
authors: Department of Environmental Science and Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do, Republic of Korea.
authors: Sanath
authors: S
authors: Kondaveeti
authors: Booki
authors: B
authors: Min
mesh_terms: D000641:Ammonia / Q000737:chemistry / Q000378:metabolism*; D058440:Denitrification / Q000502:physiology*; D055664:Electrochemical Techniques; D004566:Electrodes; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D012722:Sewage / Q000382:microbiology*
chemical_list: D009566:Nitrates; D012722:Sewage; D000641:Ammonia