engleski

Simultaneous nitrification and denitrification in horizontal rotating tubular bioreactor

In this investigation simultaneous nitrification and denitrification with bacterium Paracoccus denitrificans has been studied in horizontal rotating tubular bioreactor (HRTB). The interior of HRTB is characterized by O - ring shaped partition walls what together with bioreactor wall performed an area suitable for microbial biofilm development. After microbial biofilm development on the inner surfaces of HRTB conditions for simultaneous nitrification and denitrification as one step process were created. The main goal of this investigation was to study the effect of bioreactor process parameters [medium inflow rate (F = 0, 5 - 2, 5 L h^-1) and HRTB rotation speed (n = 5 - 30 min^-1)] on the dynamics of bioprocess in HRTB. In this investigation acetate consumption was in the range of 50, 0 - 96, 6 % by all combination of bioreactor process parameters (n, F). Nitrite, nitrogen (II) oxide and nitrogen (I) oxide were detected as intermediers of ammonium degradation during simultaneous nitrification and denitrification. pH gradient (cca 1 pH unit) along HRTB were observed only for medium inflow rate of 2, 5 L h^-1. Biofilm thickness and nitrit concentration were gradually reduced with increase of bioreactor rotation speed when medium inflow rate was in the range of 0, 5 - 1, 5 L h^-1. Further increase of medium inflow rate (2, 0 - 2, 5 L h^-1) did not have significant effect on the biofilm thickness and nitrit concentration along HRTB. On the bases of obtained results it can be concluded that simultaneous nitrification and denitrification can be successfully done in HRTB as one step process.

horizontal rotating tubular bioreactor; Paracoccus denitrificans; simultaneous nitrification and denitrification; biofilm

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