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Comparative LCA of conventional and innovative wastewater treatment systems for the Norwegian context

Comparative LCA of conventional and innovative wastewater treatment systems for the Norwegian context

Kategori
Konferansebidrag og faglig presentasjon
Sammendrag
To fulfil the sustainable circular economy and sustainable development, WWTP plants have to assure the paradigm-shift from waste treatment to resource recovery. In order to perform research on that topic and help Norwegian actors to carry out that shift, the Norwegian Research Council has funded the project RECOVER. The latter is a three MEuro and five-year project conducted by the universities NTNU (Norwegian University of Science and Technology) and NMBU (Norwegian University of Life Sciences) and the research foundation SINTEF. The project also includes the companies Cambi, Doscon, Kemira, Krüger Kaldnes, Norconsult and Salsnes Filter as well at treatment plant owners. Within the RECOVER project several novel wastewater treatment configurations have been proposed with the aim to minimize energy input and CO2 emissions, maximize energy production and recovery of valuable nutrients, and meet the effluent discharge guidelines. These novel configurations and the reference systems used today in Norway have been compared based on holistic environmental profiles using life cycle assessment (LCA) as methodology. The treatment systems are classified into three categories, namely the reference designs which include: chemical precipitation, enhanced biological phosphorous removal (EBPR) using activated sludge (AS), biological nutrient removal using AS; the innovative designs which include EBPR in moving bed bioreactor (MBBR) and EBPR in membrane bioreactor (MBR), High rate MBBR and MBR; and possible future designs which include Forward osmosis (FO) with various pre-treatment. These systems have been first designed based on values derived from process calculations based on Norwegian standards. All design alternatives have been evaluated for a capacity of 1000 m3/hour and a typical wastewater composition defined according to a survey performed within the RECOVER project. Furthermore, mass balances for C, N and P have been calculated to assess the resource recovery potential for the different water treatment process alternatives. The main elements of energy use in the unit processes have been included e.g. energy for aeration of the biological reactors, pressurising dispersion water in dissolved air flotation (DAF) and energy use for fine sieves. These parameters have been used to populate the life cycle inventory of resources consumed and emissions produced in order to perform the comparative LCA. The outcome of this comparative LCA will be presented at the NORDIWA conference. As an example, Figure 1 displays a comparison performed on the wastewater treatment line where three configurations namely: Forward osmosis (FO), bio-P MBBR (BM) and MBR with bio-P (BR). The results clearly indicate that the configuration that includes FO would be the most beneficial with respect to the considered indicators. Indeed, that configuration has the smallest footprint and energy demand compared to the two other configurations while providing the largest potential for resource recovery.
Oppdragsgiver
  • Norges forskningsråd / 247612
Språk
Engelsk
Institusjon(er)
  • SINTEF Community / Infrastruktur
Presentert på
NORDIWA 2019
Sted
Clarion Hotel Helsinki
Dato
22.09.2019 - 24.09.2019
Arrangør
Finnish Water Utilities Association (FIWA)
År
2019