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- Pelkonen, Markku, et al.
(författare)
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Biological nitrogen removal from landfill leachate : A pilot-scale study
- 1999
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Ingår i: Waste Management & Research. - : Wiley. - 0734-242X .- 1096-3669 .- 1399-3070. ; 17:6, s. 493-497
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Tidskriftsartikel (refereegranskat)abstract
- A pilot-scale two-stage process including an anaerobic pretreatment (up-flow anaerobic sludge blanket, UASB) unit and a pre-denitrification activated sludge process was studied for treating leachates from a municipal landfill (waste aged 4 to 5 years, area 2.5 ha) and from a windrow composting area (1 ha). A single-stage pilot process was used for nitrification studies. The leachate characteristics were as follows: COD 740 to 2400 mg l-1 (chemical oxygen demand), BOD7 (biochemical oxygen demand) approximately 1000 mg l-1, N(tot) 40 to 120 mg l-1 and the temperature was between 2 and 21°C. The results show that 45 to 50 COD removal could be achieved in the UASB reactor even at temperatures below 10°C. The activated sludge process was operated with a 1.1 to 2.2 d hydraulic retention time and at between 8 and 21°C. The removal efficiencies were 80 to 90 for COD, over 98 for BOD7, over 90 for NH4-N and over 70 for N(tot). The dependence of denitrification efficiency on leachate biodegradable COD fraction and COD to N ratio was evaluated. Overall treatment efficiencies were good and applicable for design purposes. The total costs were estimated for a full scale pre-denitrification process at FIM 10 to 20 m-3 and FIM 50 to 90 (kg N removed)-1 (3.5 to 7 DM m-3 and 17 to 30 DM [kg N removed]-1) for a landfill representing circumstances in Southern Finland with an annual average flow of 50 m3 d-1.
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