Nitrogen removal from landfill leachate using a compact constructed wetland and the effect of chemical pretreatment
2005 (English)In: Journal of Environmental Science and Health. Part A: Toxic/Hazardous Substances and Environmental Engineering, ISSN 1093-4529, E-ISSN 1532-4117, Vol. 40, no 07-jun, 1493-1506 p.Article in journal (Refereed) Published
Onsite treatment of leachate was implemented at the Tveta Landfill, adjacent to the city of Sodertalje, Sweden. The system consists of leachate collection in a pond, precipitation of metals with chemicals, a constructed wetland, and forest irrigation. This article describes the constructed wetland and its effectiveness at removing ammonia in the system. Pulsed-discharge hydrology and wetland ecology formed the basis for the development of a compact constructed wetland (CCW). The system presented here has most design similarities with vertical sub-surface flow wetlands, though this system is run in batch mode. Chemically purified leachate and untreated leachate were applied to separate sections of the CCW using a filling and emptying schedule. A leachate treatment cycle of about 14 days duration was used, involving a 7 day submerged phase followed by a 7 day drained period. The removal efficiency varied between 40 and 75% on a mass basis. A maximum mass removal rate of up to 5.1 g m(-1) d(-1) was achieved in wetlands receiving leachate after chemical pretreatment. In wetlands receiving non-treated leachate a net release of up to 18 g m(-2) N occurred in the form of nitrate. This indicated a considerable nitrification but limited denitrification in those systems. It was unclear whether the chemical treatment enhanced the nitrogen removal efficiency because of lower toxicity and/or content of fewer competing cations, or other mechanisms. Mechanisms responsible for the NH4-N removal in the CCW system have to be further investigated.
Place, publisher, year, edition, pages
2005. Vol. 40, no 07-jun, 1493-1506 p.
chemically treated leachate, constructed wetlands, hydroperiod, inorganic nitrogen, onsite treatment, removal rates, waste-water, soil
IdentifiersURN: urn:nbn:se:kth:diva-14767DOI: 10.1081/ESE-200055899ISI: 000229287500030ScopusID: 2-s2.0-18744373872OAI: oai:DiVA.org:kth-14767DiVA: diva2:332808
QC 20100525 QC 201110112010-08-052010-08-052012-02-08Bibliographically approved