Research Article Open Access

Nitrifying, Denitrifying and Heterotrophic Biomass Present in Moving Bed-Reactor

Andreliza Carolina Del Grossi Oliveira1, Camila Zoe Correa2, Kátia Valéria Marques Cardoso Prates2 and Deize Dias Lopes1
  • 1 State University of Londrina, Brazil
  • 2 Federal Technological University of Parana, Brazil

Abstract

This study was carried out to evaluate the main bacterial communities related to the removal of nitrogen in a moving bed-reactor treating landfill leachate, relating the physico-chemical parameters with the existence of these organisms in the mixed liquor (non-attached microorganisms) and Support Material (SM). The system was operated in two phases: Phase I (without effluent recirculation) and II (with recirculation, at a flow rate of 3 times the inlet flow). To monitor the system, physico-chemical analyzes were determined in the influent and effluent: pH, alkalinity, temperature, nitrogen species, Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD). To determine the concentration of nitrifying bacteria (Ammonia Oxidizing Bacteria-AOB and Nitrite Oxidizing Bacteria-NOB) and denitrifiers, the most probable number was estimated per 100 mL (MPN.100 mL-1). The concentration of heterotrophic bacteria was estimated by determination of colony forming unit per mL (CFU.mL-1). The reactor showed a high percentage of NH4+-N removal in both phases of operation, reaching 80% removal efficiency in Phase I and 83% in II. At pH close to 5.4 NOB activity was practically ceased, with nitrite accumulation in the system. Although the oxygen concentration in the mixed liquor was above 2.0 mg.L-1 the concentration of denitrifying bacteria was not affected. The concentration of heterotrophic bacteria was above 109 CFU.mL-1, but COD removal in the system was low due to low BOD/COD ratio in the mixed liquor. Analyzing the physico-chemical results and correlating them with the microbiological, it is verified that the MPN.100 mL-1 of the nitrifying organisms were strongly affected by the effluent conditions, being necessary for an effective nitrification process the control of these parameters, mainly pH.

American Journal of Environmental Sciences
Volume 13 No. 1, 2017, 47-57

DOI: https://doi.org/10.3844/ajessp.2017.47.57

Submitted On: 13 August 2016 Published On: 25 January 2017

How to Cite: Oliveira, A. C. D. G., Correa, C. Z., Prates, K. V. M. C. & Lopes, D. D. (2017). Nitrifying, Denitrifying and Heterotrophic Biomass Present in Moving Bed-Reactor. American Journal of Environmental Sciences, 13(1), 47-57. https://doi.org/10.3844/ajessp.2017.47.57

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Keywords

  • Leachate
  • Support Material
  • Biofilm