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The influence of operational conditions in sequencing batch reactors on removal of nitrogen and organics from municipal landfill leachateFaculty of Environmental Sciences and Fisheries, Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Polandklim{at}uwm.edu.pl
Faculty of Environmental Sciences and Fisheries, Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland The removal of nitrogen and organics from municipal landfill leachate in sequencing batch reactors (SBR) was investigated in the present study. The influence of hydraulic retention time (HRT), sludge age, manner of leachate dosage (short filling period of SBR and filling during the reaction period), and operational conditions with and without a mixing phase in the SBR cycle was explored. Four series were performed. In each series, the HRT used in the four SBRs was 12, 6, 3 and 2 days, respectively. Series 1 and 2 were characterized by a short leachate filling period, whereas series 3 and 4 were characterized by filling during the 4 h duration of the reaction in the SBR cycle. In series 13 SBR reactors worked with mixing and aeration phases, whereas in series 4 they worked only with an aeration phase. The effectiveness of the removal of organics increased with the extension of the HRT of leachate, particularly under operational conditions with the mixing and aeration phases in the SBR cycle. At 12 days HRT, the SBRs with the mixing and aeration phases in the cycle (series 13) showed better results than those with only an aeration phase (series 4). However, at 2 days HRT the operational conditions in SBR reactors with leachate filling over the reaction period (series 3 and 4) were more suitable. The highest efficiency of ammonium removal was obtained in series 1 with a short leachate filling period. In this series, at an HRT of 3 12 days, the ammonium concentration in the effluent did not exceed 1 mg NNH4 L1. Nitrogen removal proceeded mainly in the aeration phase as a result of ammonium losses and, to a lesser extent, dissimilative nitrate reduction over the mixing phase. The highest percentage of nitrogen removal as a result of ammonium losses was observed in series with a short filling period and long sludge age (series 1) and also in series without a mixing phase and filling over the aeration phase (series
Key Words: landfill leachate SBR organics removal dissimilative denitrification ammonium losses wmr 8776
Waste Management & Research, Vol. 23, No. 5,
429-438 (2005) |
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