4.1. Circular PP Practices
Integrating CE principles as criteria or technical specifications into PP processes appears to be one of the most discussed CE strategies in research so far. Indeed, 19 out of 34 publications examined or mentioned the importance of integrating and identifying CE principles in the processes of GPP and SPP. Ten publications indicated in total about 50 PP good practice cases that have CE-related characteristics. These good practice cases featured in both the academic and non-academic publications demonstrate that integrating CE principles into PP processes is a growing interest and a practice that presents great potential in the frame of GPP and SPP. Some of the cases mentioned were cited as examples by several publications. For instance, the case of Herning Municipality in Denmark was mentioned twice; the municipality purchased working clothes and uniforms in 2013 with the creation of technical specifications and leasing contract performance clauses related to maintenance, repair, and recycling, which enabled it to extend the lifespan of the uniforms [66
The literature seemed to divide circular PP efforts between those introducing CE technical specifications for the product itself and those introducing criteria promoting circularity in the process of procurement [71
]. As shown in Table 3
, product-focused specifications seem to be most applied and researched for remanufactured products and for recycled content in products purchased, with 12 and 13 good practice cases identified respectively. Conversely, requirements for recyclability and the disassembly of products appear to be less widespread in the literature, with only four cases identified for these categories altogether. A reason for this result might be that certain circular criteria are more easily incorporated in current PP processes. Moreover, highlighted in six studies, new considerations in the procurement processes are taken into account to help with the sustainable use of resources in PSOs [70
]. Examples are found in the food and catering sector, where new approaches to the handling, processing, and delivery of products are presented. The sizes of the lots ordered, seasonal food opportunities, local production and cooperation, logistics, experiments, and innovative recipes are considered as criteria for procurement [66
Furthermore, the procurement of services instead of the products seems to be an increasing practice, designated in seven publications. Indeed, Milios [5
] and Öhgren et al. [63
] highlighted the potential of product–service systems solutions to promote circularity and also recognized the challenges of overcoming “a web of technical, institutional and regulatory barriers [that] can impede such solutions and that extensive work in change management is required in order for such procurement to progress” [63
] (p. 155). On the other hand, business models such as sharing services or alternative waste management systems tend to be less present in the literature. However, another article linking CE and sharing economy in the public sector stated that “many public agencies have already begun to change procurement practices focusing on peer rental” [81
] (p. 81). Another example of integrating CE criteria through business model change was mentioned in the EMF report on a toolkit for policy-makers where publicly owned hospitals in Denmark could adopt performance-based business models in procurement for imaging/radiation equipment and choose access over ownership business models for a broad range of products, thus becoming leaders in recycling and waste reduction [24
Those PP practices recognized in the selected literature cover a wide range of sectors. The most generally identified is the construction and infrastructure sector, with several cases requiring the use of recycled material in the construction of public buildings. This result was consistent with the current literature on CE stating that “the construction industry is the biggest buyer of resources, and has become a leading greening industry: the reuse of materials instead of disposal is today the preferred option in most new infrastructure projects” [59
] (p. 43). Thereafter, Table 4
highlights that the sectors of furniture and transportation seem to be significant circular PP sectors. Requirements for remanufactured furniture, for the possibility of disassembly of furniture, as well as for the leasing of furniture were the specifications identified in the selected papers. Procurement of buses fueled with biowaste [66
] as well as the procurement of car-sharing services for public administration employees [70
] were mentioned in multiple studies as prevalent practices. One of the reasons that those sectors are prominent in this review might be because they are some of the major product categories of EU’s GPP voluntary instrument [70
Additionally, extending the lifetime of Information and Communications Technology (ICT) products such as computers through the procurement of remanufactured and/or reused electronic equipment and the use of related ecolabelling of such devices in PP was researched by Crafoord et al. [64
] and Gåvertsson et al. [65
]. The use of the European Ecolabel in particular was also pointed out as a useful environmental criterion in GPP to promote its implementation on products in a study assessing the growing acceptance of the EU Ecolabel in the European Union and Spain [76
]. This mention of the EU Ecolabel is linked to CE because the label identifies products that have a reduced environmental impact throughout their lifecycle [90
] and also because it is supported by the most prominent common market and consistently updated with ecological criteria in line with CE [76
]. One of the analyzed works highlighted also the potential of introducing labels indicating the amount of recycled or reused material and components in products to advance CE practices, although there is a need for circularity metrics to assess such performances [61
]. Ecolabels are considered a key tool informing the public procurers in the design of public tenders where ecolabelled products represent a guarantee that the product has the associated environmental or circular requirements [44
]. These results confirmed observations made in previous studies on environmental labelling acknowledging that public agencies are encouraged to use environmental and social labels in their acquisition processes to improve their sustainability profile [13
]. Similar to the use of ecolabels, the use of Life Cycle Assessment (LCA) and life cycle costing were demonstrated as key decision-making criteria for the selection of bidding companies for a change of public outdoor lighting to LED technology [69
]. That study proposed a novel multi-criteria model where aspects of environmental impacts generated in the manufacturing processes of LED luminaires evaluated by LCA techniques were considered in the decision to opt for LED developments in public lighting, in addition to economic and technical aspects. Although the use of life cycle thinking tools such as LCA does not guarantee the circularity of products, it is a useful tool that contributes to CE by evaluating products and services, thus enabling criteria setting and helping procurers understand the amount of emissions and impacts, produced and embedded [44
The waste management and sewage treatment sector was also highlighted, with the recycling and reuse of nutrients in the treatment of sewage sludge as a PP criterion and the procurement of waste separation systems as a CE purchasing practice [66
]. The purchasing of sustainable food or catering services, of textiles promoting the reuse, repair, and disposal of working clothes [73
], as well as specifications for recycled and recyclable cleaning products and paper were also highlighted in the sampled literature [70
]. All these sectors were consistent with the major sectors relevant to procurement by the public administration sector, as indicated in a Joint Research Centre (JRC) report that identified the best environmental management practices in this sector [48
In addition to the circular PP practices mentioned, other studies highlighted the importance and potential of implementing CE principles in PP processes as a driving force in accelerating the transition towards CE and sustainability, for instance, to promote CE in cities [74
], to boost the plastic waste recycling industry by introducing requirements of recycled plastic in products [75
], and to allow innovative product–service system solutions to enter the market by implementing PP for innovation [5
]. Moreover, Marrucci et al. [62
] linked GPP as a Sustainable Consumption and Production (SCP) tool to CE in the consumption phase by advocating that integrating CE principles into PP processes can help buyers take a more holistic approach to sustainability and help GPP to move beyond the classic process of procuring only, with the goal of reduced environmental impact but also considering closed energy and material loops within entire supply chains.
Interestingly, all the publications from the literature sample examining the integration of CE into PP pointed out that, despite the identified efforts to start the incorporation of CE in PP processes as seen through these 50 cases in practice, there is still a slow implementation of such practices generally. The complexities, challenges, and barriers highlighted by these authors refer to issues regarding the lack of knowledge, competence, experience, and skills, and thus a lack of training [5
]. In this context, several authors highlighted the need for investments in education and training initiatives to enable procurers to identify more easily opportunities for circularity in PP and emphasized the need for more cooperation, dialogue, and exchange of experiences among public authorities to spread best practice and to scale up the successful achievements in the development of procurement criteria and contracting conditions [63
]. Furthermore, Dahl Sönnichsen and Clement [44
] concluded from a literature review that key in implementing circular PP are organizational aspects such as top-managers and cross-departmental management having a leadership and strategic perspective; individual behavioral aspects such as human agency, motivation, and beliefs; and operational tools such as ecolabels, LCA, and life-cycle costing. Most importantly, the main conclusion consistently highlighted was that awareness and knowledge are clear success factors, which “through education, training and clear political goals are all crucial to enhance circular public procurement and to support effectiveness in the tender process” [44
] (p. 9) via initiatives such as best practice training, workshops, and monitoring.
Studies also referred to the lack of interaction with markets and companies as a key reason for the slow transition to circular PP [66
], hence stressing that collaboration with suppliers and other organizations is crucial to successfully implementing CE principles in PP. Witjes and Lozano [67
] demonstrated that collaboration entails a change of focus from the technical specifications set up by the procurer to a more collaborative discussion of the definition of the proposed technical and non-technical specifications between the supplier and procurer, thus enabling parties to gain experience. Rainville [73
] showed how innovative cooperation mechanisms, specifically, how the role of consultations with external groups, of intermediaries between buyers and suppliers during the pre-procurement phase, of articulating and defining the appropriate demand with ambitious criteria play a critical role in the success of ensuring procurement and its market impacts. Furthermore, the United Nations Environment Programme (UNEP) report on circular PP [71
] emphasized the similar point that engaging market dialogue already in the design and definition of specifications phases is critical to ensure embedded circularity, to enable co-creation of circular solutions, and to trigger innovation. These results indicate a need for a redefinition of the current PP rules and processes and for a redesign of the way PSOs are setting up contracts [63
]. In fact, this redefinition is argued to be a matter of changing the collaboration dynamics that are currently in place in conventional PP processes. Integrating CE principles into PP also means incorporating different ways of doing procurement, different ways of collaborating between stakeholders. Collaboration is one of the guiding principles of CE, according to the British Standards Institution (BSI) framework for CE [23
The high proportion of studies related to PP and CE in the literature sample reflects the importance and potential of PP as a leverage point for the CE transition that is pointed out in the general CE literature. Introducing CE-related criteria in PP processes is one of the unique tools related to organizational sustainability, which also has a considerable impact on the market, companies, and supply chains [72
]. Considering the public sector, its ministries, agencies, and departments as buyers of resources that have the duty to purchase responsibly is one of the main roles that PSOs must shift from linear to circular thinking.
4.2. CE Practices and Strategies in Internal Processes and Operations
When considering PSOs as consumers and users of resources, their internal processes and operations are an important area of action where CE practices and strategies have the potential to contribute to sustainability. In total, seven publications were found with CE practices and strategies pertaining to this area of PSOs, such as the collection and recycling of used work uniforms, the recovery of heat from data centers [77
], the provision of reusable mugs, the implementation of a marketplace online platform for the reuse of products and furniture by staff, as well as circular approaches to lighting and heating in buildings, to water management such as automated taps and smart flushing in toilets, and approaches to waste management by providing recycling facilities [79
Four out of the seven works investigated the implementation of CE in Higher Education Institutions (HEIs) [10
]. These publications highlighted a good level of engagement in CE practices from this type of PSO, although they concluded that the majority of initiatives are oriented towards energy and resource efficiency, product-life extension, waste reduction, and recycling, as well as emissions reduction [78
]. In one of the works, a participatory method was used to show that the four most valued strategies to start the implementation of CE in a HEI are to (1) encourage refurbishment and leasing of remanufactured furniture, (2) offer the choice of reusable mugs and food containers with take-back systems, (3) establish pay-per-use systems for appliances, and (4) pay-per-lux systems for the provision and maintenance of lighting equipment [78
]. Similarly, the EC report presenting best practices to implement CE with an EMAS gave the example of a German university certified with an EMAS as a PSO case study. It highlighted CE initiatives according to four categories: (1) initiatives related to the procurement of sustainable products; (2) initiatives optimizing the use of resources such as for events and with the installation of separated waste-collection systems; (3) initiatives improving the design of products and processes with digitization of administration processes, online meetings, and e-learning programs; and (4) initiatives aiming at the minimization of waste by promoting, for instance, the use of reusable dishes, bottles, and cups, as well as sharing platforms for various goods and services [10
]. Moreover, in the other study undertaken by Mendoza et al. [79
], a background analysis was done to get an overview of a university’s engagement in CE by analyzing their main resource and sustainability policies against the EMF’s ReSOLVE checklist. The results showed that most of the sustainability strategies belonged to the Optimize action area of the ReSOLVE checklist, with initiatives related mainly to reducing the greenhouse gas (GHG) emissions from the energy, travel, construction, and purchasing sectors [79
]. Additionally, the EMF’s report indicated public administration and defense as economic sectors in their analysis and evaluated that the areas of Share and Virtualize have the highest priority and relevance [24
]. This coincided with the results from the previously mentioned papers on the HEI’s increased interest and acknowledged opportunity of adopting performance-based models for lighting, heating, and the use of appliances, and of having sharing initiatives enabling the reuse of products and other services.
A number of practices related to the sharing economy for PSOs were examined by Ganapati and Reddick [81
], who argue that public agencies have the potential to become users of the sharing economy. Digital government platforms to share and use the in-house equipment at capacity, or the use of ride-hailing and car-sharing services by employees to make trips on demand, or even the use of coworking practices such as teleworking or desk-sharing, for instance, enhance the scope of sharing underutilized assets within large government agencies and between different government agencies. PSOs can thus use assets at capacity for both realizing internal organizational efficiencies and enhancing external public services [81
Although the CE practices and strategies highlighted above were valued by the authors as a valid starting point and evidence of CE implementation within PSOs, they have also been characterized as incremental and limited to the scope of tackling resource efficiency and waste reduction rather than promoting the rethinking of current unsustainable processes [80
]. Consequently, the results of these studies suggest that the implementation of further CE-related initiatives encourage the development of eco-effective mindsets and behaviors, resulting in long-term organizational sustainability [80
]. CE and sustainability training and complementary education of students, employees, and leaders are recommended to tackle the lack of understanding on the practical application of CE and the lack of leadership support and exemplary pro-environmental behavior by leaders that would help motivate employees to be more aware and act in a more sustainable way thereafter [78
These studies also emphasized the need to promote more radical changes by calling for the creation of dedicated working groups, for new governance dynamics, and for increased collaboration with other universities, local businesses, and other relevant stakeholders on CE-related topics to co-create solutions for shared benefits and mutual support for all parties involved [79
]. Another challenge identified in the literature is the lack of appropriate assessment-based decision-support frameworks, data collection, reporting systems, and circularity performance indicators to further embed CE thinking in PSOs [78
]. This observation was also made by Migliore et al. [61
] regarding the development of reuse and recycled content labels on products available for procurement.
Furthermore, it is critical to mention that several studies in this section, such as Mendoza et al. [79
], identified the importance of organizations to decide on the strategic value that CE would bring to the organizational sustainability management and the need to adequately embed those values in the policies, goals, and priorities of the organization so that the development of CE practices and strategies have the potential to go beyond incremental improvements and radically challenge current activities.
While investigating the organizational environmental performance of three wastewater treatment plants as a type of PSO, Seifert et al. [28
] also observed that there is a strong focus on end-of-pipe solutions that do not consider upstream activities and other relevant stakeholders influencing the environmental impacts of wastewater. In order to change this traditional paradigm, which is concentrated mostly on downstream practices such as those related to energy and resource efficiency, as previously mentioned in other articles [78
], this study highlighted the need to reduce this focus by acting on upstream activities and rethinking current practices in a whole sector. The authors suggested that this could be done through information exchange with other organizations in the sector, through active involvement of local and national associations that could contribute to changes of current potentially unsustainable activities, and through increased stakeholder dialogue in addition to improvement of the organizational environmental performance of the wastewater treatment plant public service organizations.
This section analyzed the few publications related to the integration of CE into the internal operations part of PSOs, with the main focus on HEI. Consequently, there is a need for complementary empirical studies on how the integration of CE ideas is taking place in other types of PSOs and for more conceptual approaches and frameworks to assist and ensure that the implementation of CE is providing authentic sustainability benefits.
4.3. CE Practices and Strategies in Public Service Delivery
Eight studies were found that identify opportunities and suggest new practices using CE principles to help public services contribute to a more sustainable management and performance of the public sector. Grohmann et al. [82
] explored the potential reuse of pruning waste collected on public land as a material source to create panels for thermal insulation, and thereby contribute to the sustainable management of public urban areas. Another work also examined the practice of reuse in the context of heritage buildings such as monasteries, proposing an integrated evaluation model to support the choice of the best alternative reuse of these types of buildings, thus optimizing the use of public spaces and public buildings [85
]. Moreover, the public transport sector was also highlighted with a study examining the use of buses fueled with renewable energy in the form of biogas as an innovation that reuses biowaste from the treatment of sewage, food waste from households, and manure to deliver the service of public transport [68
]. The presence of these studies in the literature sample indicated that there is a focus on the practice of reuse to implement CE in the public service delivery area of PSOs.
The sharing economy was also emphasized as having the potential to enhance traditional public services by providing access to the services on demand anywhere and anytime, according to Ganapati and Reddick [81
]. Linking the sharing economy to the smart cities concept, PSOs can leverage the power of information technology to deliver public services by efficiently using resources through peer-to-peer renting.
In the waste management sector, Santos et al. [87
] examined the use of CE-related measurement tools such as social LCAs to help improve municipal services with the management of illegal waste dumping sites on public areas in a more sustainable way, thus highlighting the importance of CE-related assessment and performance measurement tools such as LCAs in the implementation of circularity within public service delivery. This result was consistent with the sustainability management literature that acknowledged the importance of assessment methods to support decision-making processes in PSOs and to improve the management of resources and mitigate their impacts on the environment, society, and the economy [91
Furthermore, Lewandowski [83
] introduced the concept of the Public Sector Business Model (PSBM), where a business model framework is applied to PSOs. Lewandowski pointed out the benefits of business model innovation for PSOs for the delivery and capture of CE value [86
]. A PSBM is a multiple-value creation system of public services with a co-creation delivery-capturing process involving the active participation of stakeholders and various forms of cooperation. In other words, the author proposed a conceptual model of how PSOs have the potential to co-produce more circular public services together with companies and civil society. Referring to the CE as defined by the ReSOLVE action areas, the study argued that design is the entry point to incorporate circularity in PSBM, involving the active participation of citizens and companies in the creation and delivery processes of the public services [84
]. As an example of this engagement process contributing to CE, the author gave the example of the implementation of under-the-pavement wireless charges for electric public buses in the city of Tel-Aviv in Israel. The installation of these wireless charges is seen as a CE practice through the application of advanced technology replacing older solutions, referring to the ReSOLVE action of Exchange from the EMF checklist of actions. This initiative shows that, in its design and testing phase on a portion of a specific bus route, the public sector worked together with a company to design and deliver a public service in an alternative way in line with CE principles, which has the potential to benefit all parties financially, politically, and in terms of citizen satisfaction.
Three studies focused their research on the benefits of Public-Private Partnerships (PPPs) as a valuable strategy to improve the sustainability and circularity of public service delivery. PPPs are beneficial strategies contributing to CE when they improve public services through the involvement of the private sector in the application of CE principles. Qi et al. [88
] examined, for instance, a PPP in the context of an industrial solid waste exchange case in China, where the private sector is working with the public sector and educational organizations to design a collaborative program of material exchange undertaken by manufacturers rather than by local government facilities. This example of PPP is considered a CE public service because an industrial symbiosis network was viewed by the authors as an environmental protection service. Similarly, Gorbatchev and Zenchanka [89
] demonstrated how three examples of PPPs helped to improve the municipal waste management system in Belarus through the incorporation of the private sector to collect waste and recover recyclables or to install a degassing process reducing the amount of greenhouse gas (GHG) emissions from the landfills. Additionally, the paper by Bao et al. [86
] presented a case where the development of a PPP is used as an innovative procurement model for the public sector to recycle their construction and demolition waste. Procuring and using a recycling service from the private sector to manage and close the material loop in the public sector through the recycling of waste emanating from the construction and demolition of public buildings is another example of collaborating and using synergies from both the private and public sectors to change public service delivery towards more circularity.
Similar to the previous sections, the results of this section also highlighted that collaboration and stakeholder engagement are crucial aspects and values to incorporate in PSOs so that CE is appropriately implemented. This observation might be due to the fact that the implementation of CE depends on the context and circumstances in which the practices and strategies are implemented. This aspect was pointed out by previous literature arguing that some practices and strategies pertaining to CE might not be appropriate and sustainable in a given case and thus calling for “a broader and much more comprehensive look at the design of radically alternative solutions, over the entire life cycle of any process as well as at the interaction between the process and the environment and the economy in which it is embedded” [92
] (p. 12).