A Comparative Life Cycle Assessment of Advanced Processes for the Removal of Pharmaceutical Residues in Wastewater A Detailed Analysis Based on a Pre-study by Gryaab at Rya Wastewater Treatment Plant
Ladda ner
Typ
Examensarbete för masterexamen
Program
Industrial ecology (MPTSE), MSc
Publicerad
2022
Författare
Andersson, Sara
Karlsson, Maria
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
There are no requirements for wastewater treatment plants to treat pharmaceutical residues
today. However, the Swedish Environmental Protection Agency has distributed grants to
investigate solutions for improving the aquatic environment. Gryaab received grants in 2019 to
examine processes for the removal of pharmaceutical residues. A pre-study including a
multicriteria-analysis was conducted where three processes were investigated: ozonation,
Pulverized Activated Carbon (PAC), and Granular Activated Carbon (GAC). The result showed
the importance of further studies on the processes’ environmental impact, leading to this life
cycle assessment (LCA) study.
This LCA study analysed the processes from five midpoint impact categories: global warming
potential, fossil depletion, energy use, eutrophication potential, and acidification potential. The
aim was to provide Gryaab with useful data regarding which of the three processes is the
environmentally preferable choice and regarding the major environmental impacts of each
advanced process. Furthermore, several sensitivity analyses were made to depict what parts of
the advanced processes are most crucial for the total environmental impact.
This study included two functional units to enable comparisons with both the pre-study and
with other LCA studies. They were: the treatment of Gryaab’s wastewater for the removal of
pharmaceutical residues for one year; and the treatment of one m3 of wastewater to this end.
The calculations in this LCA were made in the software GaBi 9.2.1 Education, where the three
processes and the existing sludge treatment were modelled separately. All flows were added in
GaBi per m3 of wastewater and then scaled up for the yearly functional unit.
According to the results, ozonation with wind power and the GAC process with renewable
GAC, wind power, the largest possible bed volumes, and a regeneration plant at Rya wastewater
treatment plant were considered the two most preferable alternatives in terms of environmental
impact. Ozonation contributed the most to the midpoint impact category energy use. The PAC
process contributed the most to global warming and acidification, while global warming was
most significant for the GAC process. The value of using renewable alternatives where it is
possible was thus strengthened. However, the environmental benefit of advanced wastewater
treatment in comparison to its environmental burden must be further analysed to conclude if an
implementation is environmentally advantageous.
Beskrivning
Ämne/nyckelord
Gryaab , Rya , WWTP , Advanced wastewater treatment , Life Cycle Assessment , Ozonation , PAC , GAC