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The effect of HRT, current density, and packing ratio on nitrate nitrogen removal efficiency and current efficiency in BRM-BER  

Whang, Gye-Dae (경희대학교)
Lee, Sang-Keun (경희대학교)
Sung, Hae-Chang (경희대학교)
Publication Information
Journal of Korean Society of Water and Wastewater / v.24, no.4, 2010 , pp. 433-442 More about this Journal
Abstract
BER at different packing ratios of bio-ring media(BRM) was tested to investigate the effect of varying hydraulic retention time (HRT) and current density on the nitrate removal and current efficiency. In the preliminary batch mode experiment of BERs, current density was applied at 2.0 A/$m^2$, 4.0 A/$m^2$, 4.8 A/$m^2$, which correspond to the designation of reactor #1, #2, #3, respectively. The reactor #2 showed a highest nitrate removal rate of 162.0 mg $NO_3{^-}$-N/L/d, and the kinetics of nitrate removal rate was defined as the Zero order reaction. In the primary experiment of BERs, four BERs packed with BRM were operated in varying HRT and current, and the packing ratios of reactor #1, #2, #3 and #4 were 0%, 8%, 16%, 24%. respectively. This results of the experiments indicated that the nitrate removal rate and current efficiency were increased significantly cause of growing of autotrophic denitrification microorganisms on the surface of cathode and media by increasing of the current density and decreasing of HRT. However, The decreasing of nitrate removal rate and current efficiencies were observed in the condition of HRT of 5.25 hr and 4.8 A/$m^2$ of current density. With more increasing current density and decreasing of HRT, the hydrogen inhibition occurred at the surface of cathode. Moreover, nitrate removal rate by autotrophic denitrification microorganisms attached on the media surface was observed to be limited by no longer increasing dissolved hydrogen concentration of each reactor. In conclusion, the highest nitrate nitrogen removal and current efficiency could be achieved when the BER was operated at the conditions of 7 hr HRT, current density of 4.0 A/$m^2$, and 16% packing ratio. And it was found that the amount of nitrate removal by microorganisms attached on the surface of cathode and media (BRM) was 178.2 mg/L and 52.2 mg/L respectively. and the amount of nitrate removal per MLVSS was 0.435 g $NO_3{^-}$-N/g $MLVSS{\cdot}d$ and 0.336 $NO_3{^-}$-N/g $MLVSS{\cdot}d$.
Keywords
Hydrogen utilization denitrification; Biofilm Electrode reactors (BER); Current density;
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1 Kurt M. Dunn U., Bourne J. R. (1987) Biological denitrification of drinking water using autotrophic organisms with H2 in a fluidized-bed biofilm reactor, Biotechnol. Bioeng., 29, pp. 493-501.   DOI   ScienceOn
2 Lee K. C., and Rittmann B. E. (2002) Applying a novel autohydrogenotrophic hollow-fiber membrane biofilm reactor for denitrification o drinking water, Wat. res., 36, pp. 2040-2052.   DOI   ScienceOn
3 Sakakibara, Y., Kuroda, M. (1993) Electric prompting and control of denitrification, Biotechnol. Bioeng., 42, 535-537.   DOI   ScienceOn
4 Vasiliadou, I. A., S. Siozios, I. T. Papadas, K. Bourtzis, S. Pavlou, D.V. Vayenas (2006) Kinetics of Pure Cultures of Hydrogen-Oxidizing Denitrifying Bacteria and Modeling of the Interactions Among Them in Mixed Cultures, Biotechnology and Bioengineering, 95(3), pp. 513-525.   DOI   ScienceOn
5 Ghafari, S., Masitah Hasan, Mohamed Kheireddine Aroua (2009) Effect of carbon dioxide and bicarbonate as inorganic carbon sources on growthand adaptation of autohydrogenotrophic denitrifying bacteria, Journal of Hazardous Materials, 162, pp. 1507-1513.   DOI   ScienceOn
6 Islam, S., Suidan, M.T. (1998) Electrolytic denitrification: long term performance and effect of current intensity, Water Res. 32(2), pp. 528-536.   DOI   ScienceOn
7 Kikuchi K., Yoshinori Tanaka , Yasuhiro Saihara, Miho Maeda, Masaaki Kawamura ,Zempachi Ogumi (2006) Concentration of hydrogen nanobubbles in electrolyzed water, Journal of Colloid and Interface Science, 298, pp. 914-919.   DOI   ScienceOn
8 Feleke Z, Araki K, Sakakibara Y, Watanabe T, Kuroda M. (1998) Selective reduction of nitrate to nitrogen gas in a biofilm-electrode reactor, Water Res., 32(9), pp. 2728-2734.   DOI   ScienceOn
9 APHA, AWWA, and WEF (2005) Standard methods, Washington D.C: APHA