Abstract
Abstract The efficiency of different leachate treatment methods for the removal of refractory organic compounds and ammonium-nitrogen was investigated. The methods evaluated were nitrification, denitrification, adsorption onto activated carbon, precipitation by ferric chloride or aluminum sulphate and oxidation by ozone or Fenton´s reagent. Furthermore, analyses were performed on leachates from municipal landfills of different kinds (a biocell deposit, a conventional mixed landfill containing household and industrial waste, and an ash deposit) in order to study the leachate composition in regard to various hydrophobic organic compounds as a function of the type of waste deposited.
The results suggested that, in order to achieve a satisfactory removal of both ammonium-nitrogen and organic substances, the treatment of methanogenic leachates should be performed through a process combining biological and physical or chemical stages. When the biological treatment was not combined with a physical or a chemical process a COD removal of only 20-30% was achieved, wheras the toxicity of the leachate was significantl reduced. In contrast, a combination of nitrification and either adsorption onto activated carbon or oxidation using Fenton´s reagent resulted in a COD removal of about 80%, although certain specific organic compounds, such as phthalates, were unaffected by the treatment. A combination of nitrification, precipitation by ferric chloride and adsorption onto activated carbon removed 96% of the TOC.
The analyses of leachates from municipal landfills of different types showed the leachate from the ash deposit to contain more C4-substituted phenols than the other leachates and to likewise contain alkanes,which the others did not.
The results suggested that, in order to achieve a satisfactory removal of both ammonium-nitrogen and organic substances, the treatment of methanogenic leachates should be performed through a process combining biological and physical or chemical stages. When the biological treatment was not combined with a physical or a chemical process a COD removal of only 20-30% was achieved, wheras the toxicity of the leachate was significantl reduced. In contrast, a combination of nitrification and either adsorption onto activated carbon or oxidation using Fenton´s reagent resulted in a COD removal of about 80%, although certain specific organic compounds, such as phthalates, were unaffected by the treatment. A combination of nitrification, precipitation by ferric chloride and adsorption onto activated carbon removed 96% of the TOC.
The analyses of leachates from municipal landfills of different types showed the leachate from the ash deposit to contain more C4-substituted phenols than the other leachates and to likewise contain alkanes,which the others did not.
Original language | English |
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Qualification | Doctor |
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Award date | 1998 Apr 24 |
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Publication status | Published - 1998 |
Bibliographical note
Defence detailsDate: 1998-04-24
Time: 10:15
Place: Chemical Center, Sölveg. 39 Hörsal B
External reviewer(s)
Name: Ek, Mats
Title: Tekn. Lic
Affiliation: The Swedish Environmental Research Institute, Stockholm
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Article: I. Welander U. (1997) Identification by Gas Chromatography of Organic Constituents in Leachates from Sanitary Landfills. Resource and Environmental Biotechnology 1:283-296.
Article: II. Welander U., Henrysson T. and Welander T. (1997) Nitrification of Landfill Leachate using Suspended-Carrier Biofilm Technology. Water Research 31: 2351-2355.
Article: III. Welander U., Henrysson T. and Welander T. (1998) Biological Nitrogen Removal from Municipal Landfill Leachate in a Pilot-scale, Suspended Carrier Biofilm process (in press Water Research).
Article: IV. Welander U. and Henrysson T. (1998) Degradation of Organic Compounds in a Municipal Landfill Leachate Treated in a Suspended Carrier Biofilm Process (in press Water Environment Research).
Article: V. Welander U. and Henrysson T. (1998) Physical and Chemical Treatment of Nitrified Leachate from a Municipal Landfill (in press Environmental Technology).
Subject classification (UKÄ)
- Industrial Biotechnology
Free keywords
- physical/chemical treatment
- biological treatment
- characterization
- organic substances
- leachate treatment
- municipal landfill
- Biotechnology
- Bioteknik