Chemical denitrification for nitrogen removal from landfill leachate
2005 (English)In: Water Science and Technology, ISSN 0273-1223, Vol. 52, no 10-11, 509-516 p.Article in journal (Refereed) Published
A new system that removes nitrogen from landfill leachate and other waste waters with similar properties has been proposed with nitritation (i.e. oxidation of ammonium to nitrite) of half of the influent ammonium followed by chemical denitrification with a reaction between equal amounts of ammonium and nitrite to form nitrogen gas. Chemical denitrification occurs at high concentrations and the reactions were studied in combination with a concentration step. Studied concentration methods were freezing/thawing and evaporation/drying. Chemical denitrification is well-known in inorganic chemistry and has been observed in natural systems. Studies in laboratory were focused on chemical denitrification and showed that nearly complete removal of soluble nitrogen can be obtained in evaporation/drying of water solutions or leachate with equal amounts of ammonium and nitrite. Freezing/drying was less efficient with a removal of about 50-60% at high initial concentrations. Chemical denitrification is much influenced by concentration, pH-value, temperature and some compounds in leachate have an inhibiting effect on the reaction. Factors as safety (ammonium nitrite as a salt is explosive above 60 degrees C) and possible side-reactions as formation of ammonia and nitrogen oxides must be carefully evaluated before use in full-scale. Conductivity is a suitable parameter to follow-up the chemical denitrification process.
Place, publisher, year, edition, pages
2005. Vol. 52, no 10-11, 509-516 p.
chemical denitrification, evaporation, freezing, leachate
Oceanography, Hydrology, Water Resources
IdentifiersURN: urn:nbn:se:kth:diva-42669ISI: 000234617700058ScopusID: 2-s2.0-31844436347OAI: oai:DiVA.org:kth-42669DiVA: diva2:447374
QC 20111011. 4th World Water Congress of the International-Water-Association. Marrakesh, MOROCCO. SEP 19-24, 2004 2011-10-112011-10-112011-10-11Bibliographically approved