Chalmers Conferences, LCM 2013

Birgitte Sørensen, Ole Dall

Last modified: 2014-09-11


The Danish waste treatment plant for hazardous waste “Nordgroup a/s”
plans to recover phosphorus from waste water sludge. The presented LCAstudy
indicates that environmental impacts by phosphorous recovery in an
energy efficient process are at the same level or lower than through the reuse
of sewage sludge applied directly on farmland.
The recovery method is based on drying and thermal gasification of
activated sewage sludge followed by extraction of phosphorous from the
ashes. The obtained product can be used as a fertilizer replacing similar
products on the marked.
The conclusion is that the general rule according to waste hierarchy, where
re-use is preferable to material and energy recovery, is wrong in this case.


LCA; phosphorous; sludge; resource; gasification


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