SLUDGEFFECT: Life cycle effects from removing hazardous substances in sludge and plastic through thermal treatment

At this moment, someone you know is sitting on the toilet, deciding they want a new television. That same person is currently on painkillers due to a back prolapse or perhaps a painful shoulder? Simultaneously, this person is in the process of polluting the environment. The medications will pass though the body as metabolites and go through the sewer system to later end up either discharged into some river or coastline, or onto farms that use sewage sludge as fertilizer. The old television will release chemicals and microplastics in the environment from the moment it is crushed for recycling. Parts of the television will end up on a landfill, be recycled or incinerated for energy production. All which are processes where hazardous chemicals can be released into the environment. Sure, the impact of one person is not much, but this person is not unique. There are thousands, millions, like this person. And together this creates an undue burden of hazardous chemicals and plastics being released into the environment. The research project SLUDGEFFECT, financed by the Research Council of Norway, is identifying ways to best manage and reduce this burden. Currently the project has made a detailed mass flow analysis of sewage sludge and waste electronic and electrical equipment in Norway, and further mapped on to these mass flows the contribution of two major types of contaminants: organophosphate flame retardants in sludges and bisphenols in e-waste. Already by experimenting with alternative mass flows of sludge and e-waste, it is possible to draw conclusions on how to reduce emissions of contaminants based on changing waste management strategies. In the next phase, we will introduce results from initial experiments with a new pyrolysis technology that can remove many contaminants and even microplastic from sludge and e-waste. This new waste management strategy will be looked at as to how it can be optimized for energy efficiency or even be carbon negative. This may be possible by using biogas from the fermented sludge as a heat source for the pyrolysis to remove the contaminants within them. SLUDGEFFECT will continue to guide industry and regulators towards optimized environmental strategies for sustainable recycling of sludge and e-waste in a circular economy. It is a dirty job, but somebody must do it!

There is a scarcity of research and innovation initiatives regarding practical ways to mitigate the harmful presences of hazardous substances of sewage sludge and e-waste plastic within a circular economy. We will explore this in the context of addressing United Nation's Sustainability Goal (SDG) 12, in combination to synergies and trade-offs to other SDG. 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), we will 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. The project will be carried out by an interdisciplinary team of researchers from Norway (NGI, NTNU), Sweden (Chalmers) 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.