Allocation approaches to deal with the cascading use of resources along a water treatment chain : the case of the resource footprint of sewage sludge valorisation in The Netherlands

The paradigm shift from a linear to a circular economy has consequences on the way the sustainability of products and waste production/processing needs to be assessed. Some methodological approaches commonly used today to conduct Life Cycle Assessment (LCA) of such products become questionable when it comes to comparing (partially) recycled products with virgin material-based products. If waste streams are considered as a resource and not as a waste, it implies that part of the upstream environmental burdens should be allocated to the downstream products to allow a fair comparison with the equivalent products obtained from raw materials. This means that the “zero burden” assumption usually followed when evaluating the impact of resource recovery from waste in LCA studies (Ekvall et al., 2007) is becoming more and more questionable and allocation approaches should be applied to allocate part of the upstream environmental burdens to the recovered products. This presentation presents the application of different approaches to allocate the environmental burdens of upstream processes (in this case consumer goods, food and drinks consumed by households) to products obtained from household wastewater, through sewage sludge valorisation. These approaches are based on allocation formulas previously proposed to deal with the cascading use of materials (Allacker et al., 2017) but so far never applied in the wastewater treatment sector. They are applied to the case study of the processing of sewage sludge from the wastewater treatment plant of Eindhoven (The Netherlands) to produce fuels, chemicals and building materials. The resource footprint of these products is presented and the consequences of applying five allocation approaches is discussed

A framework for using the handprint concept in attributional life cycle (sustainability) assessment

Handprint refers to the good society does for the environment, but this definition gives room for different interpretations. While in life cycle (sustainability) assessment (LC(S)A) its use is still at infancy, the effective communication potential of Handprint terminology gives room for increasing its application in the future. The objective of this article is to propose a framework to distinguish and classify various types of handprint, when they are intended to be used in LC(S)A studies. Building on the current structure of LC(S)A regarding the cause-effect chain, from flows to impacts, a framework to allow understanding the beneficial, adverse and net effects various flows can cause to different actors is created. Based on that, three handprint types are proposed, i.e., Direct, Indirect and Relative. These types can be subdivided into more specific/complex types of handprint, e.g., Indirect Relative Handprint (adverse). Illustrations with case studies (fictive and from literature) are used to suggest some guidance. With this proposal, a first step to consistently introduce the handprint concept into LC(S)A is achieved, but future challenges still exist (e.g., development of quantitative methods for beneficial impacts from product’s functionality, in footprint-consistent units)

Toward a Framework for Resource Efficiency Evaluation in Industry: Recommendations for Research and Innovation Projects

The world is facing a tremendous resource supply challenge. One strategy of regions and nations to address this issue is to encourage research and innovation through funding programs. Most of the time, these programs require that research and innovation projects quantify potential increases in resource efficiency achieved by the projects. However, no consensus exists on how to calculate resource efficiency; therefore, a wide range of approaches is followed. As a result, resource efficiency results are not comparable between projects, and because no rules or guidelines exist to help project developers, the approach followed is not always appropriate. This paper aims to discuss the existing approaches and methods used to evaluate resource efficiency. In this context, resource efficiency is defined as the ratio between the benefits obtained from resources and the impact or amount of resources used. The most challenging step is the determination of this ratio’s denominator because a wide range of methods to quantify resource consumption exist and are being used. They can be classified as gate-to-gate or life cycle based methods and can be subdivided into accounting methods and impact assessment methods. Each method considers different aspects of resources; thus, no single method aims to answer the same research questions. Therefore, project developers must make a well informed choice about which method to use. This paper provides recommendations to support this choice, as well as the overall evaluation and the valorization of the resource efficiency ratio in the framework of research and innovation programs

Improving the resource footprint evaluation of products recovered from wastewater : a discussion on appropriate allocation in the context of circular economy

Shifting from a linear to a circular economy has consequences on how the sustainability of products is assessed. This is the case for products recovered from resources such as sewage sludge. The "zero-burden" assumption is commonly used in Life Cycle Assessment and considers that waste streams are burden-free, which becomes debatable when comparing waste-based with virgin material-based products in the context of the growing circular economy. If waste streams are considered as resources rather than waste, upstream burdens should be partly allocated to all products to allow a fair comparison with their virgin material-based equivalents. In this paper, five allocation approaches are applied to allocate the resource use of upstream processes (consumer goods production) to products recovered from the processing of sewage sludge in the Netherlands, which produces biogas, (phosphorus-based) chemicals and building materials. Except for the approach which allocates 100% of the impact from resource recovery processes to the preceding consumer goods, the allocation approaches show a resource use 27 to 80% higher than with the "zero-burden" assumption. In this particular case, using these allocation approaches is likely to find little support from recyclers. The producers of household products, recyclers and policy makers should find a consensus to consider the shift from a linear to a circular economy in sustainability assessment studies while avoiding discouraging the implementation of recovery technologies. This paper suggests starting the discussion with the approach which allocates the impacts from upstream processes degressively to the downstream products as it best translates the industrial ecology principles

Improving the resource footprint evaluation of products recovered from wastewater : a discussion on appropriate allocation in the context of circular economy

Shifting from a linear to a circular economy has consequences on how the sustainability of products is assessed. This is the case for products recovered from resources such as sewage sludge. The "zero-burden" assumption is commonly used in Life Cycle Assessment and considers that waste streams are burden-free, which becomes debatable when comparing waste-based with virgin material-based products in the context of the growing circular economy. If waste streams are considered as resources rather than waste, upstream burdens should be partly allocated to all products to allow a fair comparison with their virgin material-based equivalents. In this paper, five allocation approaches are applied to allocate the resource use of upstream processes (consumer goods production) to products recovered from the processing of sewage sludge in the Netherlands, which produces biogas, (phosphorus-based) chemicals and building materials. Except for the approach which allocates 100% of the impact from resource recovery processes to the preceding consumer goods, the allocation approaches show a resource use 27 to 80% higher than with the "zero-burden" assumption. In this particular case, using these allocation approaches is likely to find little support from recyclers. The producers of household products, recyclers and policy makers should find a consensus to consider the shift from a linear to a circular economy in sustainability assessment studies while avoiding discouraging the implementation of recovery technologies. This paper suggests starting the discussion with the approach which allocates the impacts from upstream processes degressively to the downstream products as it best translates the industrial ecology principles