SLUDGEFFECT - mitigate hazardous substances

One of the greatest barriers to achieving a circular economy is the management of hazardous substances. The United Nations Sustainable Development Goal (SDG) 12.4 emphasizes the need for sound management of wastes and chemicals through their life cycles by 2020.

This issue especially comes to the fore with two types of wastes: sewage sludge and e-waste plastic. These hold tremendous circular potential for nutrient recycling, green energy and as a replacement source of raw materials. This potential, however, is not realized due to elevated levels of hazardous substances. Using raw sewage sludge as fertilizer is problematic due to exposure through food and water ways affected by agricultural run-off; recycling e-waste plastic is problematic due to recycling hazardous substances and environmental emissions during recycling.

SLUDGEFFECT will explore this in the context of addressing United Nation's Sustainability Development Goal (SDG) 12, in combination to synergies and trade-offs to other SDGs. By combining state-of-the-art knowledge and analysis of the presence of contaminants in sewage sludge fertilizers and e-waste plastic, with the literature and novel experimentation on how to remove hazardous substances through pyrolysis at high temperature (>700 C), the aim is to provide more than a proof-of-concept that hazardous substances risks can be mitigated through high temperature pyrolysis in Norwegian waste streams while making useful raw materials.

We will investigate how to integrate this risk mitigation within a circular economy and SDG analysis, how to optimize this process to achieve a better environment footprint, and further, how to advance such technology to develop products in the current regulatory and market situation within Norway. This novel research will be conducted in close collaboration with a user group from the national, regional and industrial sectors, grounding it firmly within the Norwegian regulatory and economic context.

Project organization

The project will be carried out by an interdisciplinary team of researchers from Norway (NGI, NTNU), Sweden (Chalmers University) and Spain (IDAEA-CSIC), employ two postdocs, and have a user group from the National level (Norwegian Food Safety Authority & Norwegian Environment Agency); relevant Industry sector (Lindum AS, Scanship AS, Norsirk), and Regional actors (VEAS IKS, Trondheim Kommune). This will firmly anchor the state-of-the-art research, applications and implications within the Norwegian regulatory and market context.

More information on this is found under Project management (see the menu line above).

Work packages (WP)

In order to achieve the primary objective of SLUDGEFFECT - Identify how thermal treatments can be optimized for removing hazardous substances in sludge and e-waste plastic for increasing recycling and sustainability, the project has been divided into four work packages (WP) with the following aims:

WP1 – Mass flow

Establish a mass flow of selected hazardous substances in sludge and e-waste plastic in Norway, considering environmental emissions from the status quo.

WP2 – Carbonization

Quantify how incineration, dry pyrolysis and HTC can remove selected hazardous substances from sludge and plastic; and characterize the hazards and innovation potential of resulting residues for reducing contaminant emissions.

WP3 – Life Cycle and SDG analysis

Establish a consistent framework for advanced environmental sustainability analysis of the waste treatment options using up-to-date life-cycle assessment approaches interpreted under a SDG context.

WP4 – Implementation in a circular economy

Integrate results with user feedback and regulatory considerations for innovation and societal recommendations.

Description of the different WPs are provided under Sub-projects (see the menu line above).

The Research Council of Norway - MILJØFORSK — Miljøforskning for en grønn samfunnsomstilling provide financial support for SLUDGEFFECT.

The project organization of SLUDGEFFECT is shown in the figure below:

Project Manager Hans Peter Arp
is a senior specialist at NGI (80%) and adjunct professor at NTNU (20%), and is a steering board member of Avfallsforsk (Norway's leading network for waste related R&D). He has recently developed a method for analysing microplastics, which will be used in this project. Also, he has worked extensively with understanding how combustion and pyrolysis methods impacts contaminants.

Researchers

• Hans Peter H. Arp,
• Norwegian Geotechnical Institute (NGI), Oslo, Norway and Norwegian University of Science and Technology (NTNU), Trondheim, Norway
• Heidi Knutsen, Norwegian Geotechnical Institute (NGI)
• Erlend Sørmo, Norwegian Geotechnical Institute (NGI)
• Alexandros Asimakopoulos, Norwegian University of Science and Technology (NTNU)
• Otavio Cavalett, Norwegian University of Science and Technology (NTNU)
• Francesco Cherubini, Norwegian University of Science and Technology (NTNU)
• Gregory Peters, Chalmers University of Technology, Gothenburg, Sweden
• Damia Barcelo, IDAEA-CSIC (Spanish National Research Council), Barcelona, Spain

Two postdoctoral researchers will be associated to the project:

• Postdoc 1 
  One postdoc with a PhD in organic contaminant analysis will be project employed. The postdoc will work with contaminant analysis experts and facilities at NTNU, NGI and CSIC. The postdoc will be mostly based at NTNU, though do exchanges at NGI for microplastics and CSIC. The postdoc will be co-supervised by the project manager Arp and Prof. Asimakopoulus (NTNU).
• Postdoc 2
  One postdoc with LCA experience will work on WP3. The main supervisors will be Prof. Cherubini and Dr. Cavalett (NTNU), with co-supervision and mobility stay by Prof. Peters (Chalmers).

User Group

The user group members represent the relevant national, regional and industrial stakeholders.

At the National level

• Norwegian Food Safety Authority (Mattilsynet) regulates the use of fertilizer products, including those derived from sewage sludge;
• Norwegian Environment Agency (Miljødirektoratet) overseas the regulations related to the management and environmental presence of hazardous substances, including in wastewater, sludge and e-waste, and as part of the transition towards a circular economy.

Industry and regional actors

• Lindum AS and Scanship AS have already have been very active in innovating pyrolysis technology for sustainable, economic opportunities.
• Norsirk manages 50% of the WEEE going through Norway, and are actively looking for sustainable solutions, particularly as export is now more difficult.
• VEAS IKS and Trondheim Kommune manage sludge/organic wastes for processing as fertilizer and biogas, are represented.
• Bio4Fuel, a Norwegian Centre for Environment-friendly Energy Research (SFME) that will develop innovative technology to convert biomass and organic residues to sustainable fuels and energy will join the reference group, to incorporate the inclusion of hazardous substances, allowing for potential cross-pollination research between Bio4Fuel and SLUDGEFFECT.

Stakeholders

The primary target audiences are the

• industrial, national and municipal actors who handle sewage sludge and e-waste plastic, such as wastewater treatment plants and recycling companies
• scientists that do research related to this field
• regulatory authorities from the municipal sector, state departments, such as Landbruks- og matdepartementet og Klima- og Miljøverndepartementet, and governmental agencies such as Miljødirektoratet and Mattilsynet. These authorities are specifically concerned with limiting the release of hazardous compounds to the environment to avoid possible effects on the environment or the population.
• the end-users, the general population, that consume agricultural products grown with sludge-based fertilizers and inhabit the environment into which hazardous substances are released through unsustainable practices.

References

referred to in the description of SLUDGEFFECT

1. A. Bianchini, L. Bonfiglioli, M. Pellegrini and C. Saccani, International Journal of Environment and Waste Management, 2016, 18, 226-238, Sewage sludge management in Europe: a critical analysis of data quality. https://www.researchgate.net/publication/311273547_Sewage_sludge_management_in_Europe_a_critical_analysis_of_data_quality
2. S. Heimersson, M. Svanström, C. Cederberg and G. Peters, Resources, Conservation and Recycling, 2017, 122, 126-134, Improved life cycle modelling of benefits from sewage sludge anaerobic digestion and land application. https://www.sciencedirect.com/science/article/pii/S0921344917300277
3. D. J. Barry, The University of Western Ontario, Electronic Thesis and Dissertation Repository. 5187, 2018, Pyrolysis as an Economical and Ecological Treatment Option for Solid Anaerobic Digestate and Municipal Sewage Sludge. https://ir.lib.uwo.ca/etd/5187
4. S. Khan, C. Chao, M. Waqas, H. P. H. Arp and Y.-G. Zhu, Environmental science & technology, 2013, 47, 8624-8632, Sewage sludge biochar influence upon rice (Oryza sativa L) yield, metal bioaccumulation and greenhouse gas emissions from acidic paddy soil. https://pubs.acs.org/doi/abs/10.1021/es400554x
5. S. Smith, Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 2009, 367, 4005-4041, Organic contaminants in sewage sludge (biosolids) and their significance for agricultural recycling. https://www.researchgate.net/publication/26795123_Organic_contaminants_in_sewage_sludge_biosolids_and_their_significance_for_agricultural_recycling
6. A. Mahon, B. O’Connell, M. Healy, I. O’Connor, R. Officer, R. Nash and L. Morrison, Environmental science & technology, 2016, 51, 810-818, Microplastics in Sewage Sludge: Effects of Treatment. https://pubmed.ncbi.nlm.nih.gov/27936648/
7. G. Okkenhaug, Å. Almås, N. Morin, S. Hale and H. Arp, Environmental Science: Processes & Impacts, 2015, 17, 1880-1891, The presence and leachability of antimony in different wastes and waste handling facilities in Norway. https://pubs.rsc.org/En/content/articlelanding/2015/em/c5em00210a#!divAbstract
8. N. A. Morin, P. L. Andersson, S. E. Hale and H. P. H. Arp, Journal of Environmental Sciences, 2017, 62, 115-132, The presence and partitioning behavior of flame retardants in waste, leachate, and air particles from Norwegian waste-handling facilities. https://www.sciencedirect.com/science/article/pii/S1001074217309932
9. W. J. Hall, N. Miskolczi, J. Onwudili and P. T. Williams, Energy & Fuels, 2008, 22, 1691-1697, Thermal Processing of Toxic Flame-Retarded Polymers Using a Waste Fluidized Catalytic Cracker (FCC) Catalyst. https://pubs.acs.org/doi/abs/10.1021/ef800043g
10. R. Wang and Z. Xu, Waste Management, 2014, 34, 1455-1469, Recycling of non-metallic fractions from waste electrical and electronic equipment (WEEE): A review. https://www.sciencedirect.com/science/article/pii/S0956053X14000944
11. Y. Shen, R. Zhao, J. Wang, X. Chen, X. Ge and M. Chen, Waste Management, 2016, 49, 287-303, Waste-to-energy: Dehalogenation of plastic-containing wastes. https://www.sciencedirect.com/science/article/pii/S0956053X15302579
12. K. Öberg, K. Warman and T. Öberg, Chemosphere, 2002, 48, 805-809, Distribution and levels of brominated flame retardants in sewage sludge. https://www.sciencedirect.com/science/article/pii/S0045653502001133
13. S. E. Hale, J. Lehmann, D. Rutherford, A. R. Zimmerman, R. T. Bachmann, V. Shitumbanuma, A. O’Toole, K. L. Sundqvist, H. P. H. Arp and G. Cornelissen, Environmental science & technology, 2012, 46, 2830-2838, Quantifying the Total and Bioavailable Polycyclic Aromatic Hydrocarbons and Dioxins in Biochars. https://pubs.acs.org/doi/10.1021/es203984k
14. H. P. H. Arp, N. A. Morin, S. E. Hale, G. Okkenhaug, K. Breivik and M. Sparrevik, Waste management, 2017, 60, 775-785, The mass flow and proposed management of bisphenol A in selected Norwegian waste streams. https://www.sciencedirect.com/science/article/pii/S0956053X17300028
15. E. F. Zama, B. J. Reid, H. P. H. Arp, G.-X. Sun, H.-Y. Yuan and Y.-G. Zhu, Journal of Soils and Sediments, 2018, 18, 2433-2450, Advances in research on the use of biochar in soil for remediation: a review. https://link.springer.com/article/10.1007/s11368-018-2000-9
16. S. Hellweg and L. M. i Canals, Science, 2014, 344, 1109-1113, Emerging approaches, challenges and opportunities in life cycle assessment. https://science.sciencemag.org/content/344/6188/1109.figures-only
17. J. Wang, Z. Xiong and Y. Kuzyakov, Gcb Bioenergy, 2016, 8, 512-523, Biochar stability in soil: meta‐analysis of decomposition and priming effects. https://onlinelibrary.wiley.com/doi/full/10.1111/gcbb.12266
18. G. Wernet, C. Bauer, B. Steubing, J. Reinhard, E. Moreno-Ruiz and B. Weidema, The International Journal of Life Cycle Assessment, 2016, 21, 1218-1230, The ecoinvent database version 3 (part I): overview and methodology. https://lca-net.com/publications/show/ecoinvent-database-version-3-part-overview-methodology/
19. R. Harder, G. M. Peters, S. Molander, N. J. Ashbolt and M. Svanström, The International Journal of Life Cycle Assessment, 2016, 21, 60-69, Including pathogen risk in life cycle assessment: the effect of modelling choices in the context of sewage sludge management. https://link.springer.com/article/10.1007/s11367-015-0996-2
20. G. M. Peters and H. V. Rowley, Environmental Science & Technology, Environmental comparison of biosolids management systems using life cycle assessment. Policy Analysis, 2009. 43 (8), pp 2674–2679. https://pubs.acs.org/doi/abs/10.1021/es802677t
21. A.-M. Boulay, J. Bare, L. Benini, M. Berger, M. J. Lathuillière, A. Manzardo, M. Margni, M. Motoshita, M. Núñez and A. V. Pastor, The International Journal of Life Cycle Assessment, 2018, 23, 368-378, The WULCA consensus characterization model for water scarcity footprints: assessing impacts of water consumption based on available water remaining (AWARE). https://link.springer.com/article/10.1007/s11367-017-1333-8
22. A. Kounina, M. Margni, J.-B. Bayart, A.-M. Boulay, M. Berger, C. Bulle, R. Frischknecht, A. Koehler, L. M. i Canals and M. Motoshita, The International Journal of Life Cycle Assessment, 2013, 18, 707-721, Review of methods addressing freshwater use in life cycle inventory and impact assessment. https://link.springer.com/article/10.1007/s11367-012-0519-3
23. O. Cavalett and F. Cherubini, Nature Sustainability, 2018, 1, 799, Contribution of jet fuel from forest residues to multiple Sustainable Development Goals. https://www.nature.com/articles/s41893-018-0181-2?proof=t
24. H. P. H. Arp, H. Knutsen, Ø. Lilleeng, A. Pettersen and M. T, Miljødirektoratet report M-976, 2018, Microplastics in sediments on the Norwegian Continental Shelf. https://www.miljodirektoratet.no/publikasjoner/2018/mars-2018/microplastics-in-sediments-on-the-norwegian-continental-shelf/

Background for SLUDGEFFECT

One of the greatest barriers to achieving a circular economy is the management of hazardous substances. The United Nations Sustainable Development Goal (SDG) 12.4 emphasizes the need for sound management of wastes and chemicals through their life cycles by 2020.

This issue especially comes to the fore with two types of wastes: sewage sludge and e-waste plastic. These hold tremendous circular potential for nutrient recycling, green energy and as a replacement source of raw materials. This potential, however, is not realized due to elevated levels of hazardous substances.

Waste with hazardous substances pose a dilemma in the circular economy. The presence of hazardous substances in waste material may render that waste unsuitable for recycling or the production of secondary raw materials of high quality.

Using raw sewage sludge as fertilizer is problematic due to exposure through food and water ways affected by agricultural run-off. Recycling e-waste plastic is problematic due to recycling hazardous substances and environmental emissions during recycling. There are thermal conversion technologies, such as dry pyrolysis and hydrothermal carbonization (HTC), which can eliminate or at least transform most of these hazardous substances within sewage sludge and e-waste plastic, while converting sludge and plastic to useful energy and raw materials. However, the efficacy and environmental trade-offs of implementing these technologies are not clear.

Sewage sludge
Sewage sludge is a nutrient rich, energy rich waste product that could be utilized as a local source of green energy and can be converted to a coal substitute or fertilizer. However, sewage sludge is also loaded with carcinogenic industrial chemicals, pathogens, persistent pharmaceuticals and microplastic. These hazards are a regulatory hindrance.

Management strategies for sewage sludge are highly variable. In Europe in 2011, the rates of sludge landfilling, incineration and various types of recycling (e.g. fertilizer, composting, building materials) were (ref.1).

• 9.5% landfilling
• 23.6% incineration
• 56% agriculture and other recycling
• 11% unknown.

The Norwegian Food Safety Authority (part of the SLUDGEFFECT user group) wants to increase use of sewage sludge as fertilizer, but at the same time have tighter control on pollutant/hazard levels. Various reviews on strategies to reuse sewage sludge generally conclude that undertaking some sort of recycling (either for energy recapture or material recapture, or both) is usually more beneficial than landfilling or incineration without energy gain (ref.2); though hazardous substances were not taken into account.

Recently, an LCA-economic study found that options of pyrolysing sewage sludge to biochar, which is not commonly done on a large scale, concluded that "pyrolysis of the sludge with the use of the biochar as a coal replacement was determined to have the greatest environmental" and economic benefit, compared to other options (ref.3).

Electronic-waste
An even larger problem for the circular economy is electronic-waste (e-waste) plastic. E-waste plastic is loaded with various hazardous substances, in particular flame retardants and metals, many of which have been banned or restricted by the time the e-waste is sent for recycling, such as via the RoHS regulation (ref.7, 8).

This has led to concerns about how to best manage them. For over a decade, there has been research on utilizing pyrolysis to convert e-waste plastic into fuel (ref.9, 10); however, the presence of toxic halogenated substances in the by-products has made this difficult to make viable fuels.

More recently, however, there is promise for the combination of pyrolyzing organic material (like sewage sludge) alongside e-waste, especially at high temperature, to increase conversion of hazardous waste to inorganic residues, removable fractions or to low-bioavailable fractions (ref. 11).