Bioplastics are gaining interest as an alternative to fossil-based plastics. In addition, biodegradable bioplastics may yield biogas after their use, giving an additional benefit. However, the biodegradability time in international norms (35 days) far exceeds processing times in anaerobic digestion facilities (21 days). As the bioplastic packaging does not indicate the actual biodegradability, it is important to understand the time required to biodegrade bioplastic if it ends up in the anaerobic digestion facility along with other organic waste. For this work, cellulose bioplastic film and polylactic acid (PLA) coffee capsules were digested anaerobically at 55 ℃ for 21 days and 35 days, which are the retention times for industrial digestors and as set by international norms, respectively. Different sizes of bioplastics were examined for this work. Bioplastic film produced more biogas than bioplastic coffee capsules. The biodegradability of bioplastic was calculated based on theoretical biogas production. With an increase in retention time, biogas production, as well as biodegradability of bioplastic, increased. The biodegradability was less than 50% at the end of 35 days for both bioplastics, suggesting that complete degradation was not achieved, and thus, the bioplastic would not be suitable for use in biogas digesters currently in use.
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Currently the advances in the field of 3D printing are causing a revolution in the (bio-)medical field. With applications ranging from patient-specific anatomical models for surgical preparation to prosthetic limbs and even scaffolds for tissue engineering, the possibilities seem endless. Today, the most widely used method is FDM printing. However, there is still a limited range of biodegradable and biocompatible materials available. Moreover, printed implants like for instance cardiovascular stents require higher resolution than is possible to reach with FDM. High resolution is crucial to avoid e.g. bacterial growth and aid to mechanical strength of the implant. For this reason, it would be interesting to consider stereolithography as alternative to FDM for applications in the (bio-) medical field. Stereolithography uses photopolymerizable resins to make high resolution prints. Because the amount of commercially available resins is limited and hardly biocompatible, here we investigate the possibility of using acrylates and vinylesters in an effort to expand the existing arsenal of biocompatible resins. Mechanical properties are tailorable by varying the crosslink density and by varying the spacer length. To facilitate rapid production of high-resolution prints we use masked SLA (mSLA) as an alternative to conventional SLA. mSLA cures an entire layer at a time and therefore uses less time to complete a print than conventional SLA. Additionally, with mSLA it takes the same time to make 10 prints as it would to make only one. Several formulations were prepared and tested for printability and mechanical strength.
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In the housing market enormous challenges exist for the retrofitting of existing housing in combination with the ambition to realize new environmentally friendly and affordable dwellings. Bio-based building materials offer the possibility to use renewable resources in building and construction. The efficient use of bio-based building materials is desirable due to several potential advantages related to environmental and economic aspects e.g. CO2 fixation and additional value. The potential biodegradability of biomaterials however demands also in-novative solutions to avoid e.g. the use of environmental harmful substances. It is essential to use balanced technological solutions, which consider aspects like service life or technical per-formance as well as environmental aspects. Circular economy and biodiversity also play an im-portant role in these concepts and potential production chains. Other questions arise considering the interaction with other large biomass users e.g. food production. What will be the impact if we use more bio-based building materials with regard to biodiversity and resource availability? Does this create opportunities or risks for the increasing use of bio-based building materials or does intelligent use of biomass in building materials offer the possibility to apply still unused (bio) resources and use them as a carbon sink? Potential routes of intelligent usage of biomass as well as potential risks and disadvantages are highlighted and discussed in relation to resource efficiency and decoupling concept(s).
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Natural Deep Eutectic Solvents (NADES) represent a green chemistry alternative to utilization of common hazardous organic solvents. They were introduced by Abbott et al. [1], and were found to have a wide range of compositions and favorable properties. NADES are typically obtained by mixing hydrogen-bond acceptors (HBA), with hydrogen bond donors (HBD), leading to a significant depression of the melting point. The availability of components, simple preparation, biodegradability, safety, re usability and low cost are the significant advantages that call for research on their analytical applications. Three methods are most commonly used for preparing NADES: a) heating and stirring: the mixture until a clear liquid is formed; b) evaporating solvent from components solution with a rotatory evaporator; c) freeze drying of aqueous solutions.The common solvents for the extraction of anthocyanins are acidified mixtures of water with ethanol, methanol, or acetone. The anthocyanins extracts are susceptible to degradation due to high temperature, and the solvent properties (e.g. high pH) and the whole process can often be time-consuming. Extraction of anthocyanins from red cabbage by four NADES was investigated. It was demonstrated that NADES have comparable extraction efficiencies with conventional method with 0.1 M water solution of HCl. This indicates a possibility of utilization the Green chemistry extraction processes as a promising new green-extraction technology with low cost efficiency and environment friendly technology for production of safe food additives.
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Isolations of 3-chlorobenzoate (3CBA)-degrading aerobic bacteria under reduced O-2, partial pressures yielded organisms which metabolized 3CBA via the gentisate or the protocatechuate pathway rather than via the catechol route. The 3CBA metabolism of one of these isolates, L6, which,vas identified as an Alcaligenes species, was studied in more detail. Resting-cell suspensions of L6 pregrown on 3CBA oxidized all known aromatic intermediates of both the gentisate and the protocatechuate pathways. Neither growth th on nor respiration of catechol could be detected. Chloride production from 3CBA by L6 was strictly oxygen dependent. Cell-free extracts of 3CBA-grown L6 cells exhibited no catechol dioxygenase activity but possessed protocatechuate 3,4-dioxygenase, gentisate dioxygenase, and maleylpyruvate isomerase activities instead. In continuous culture with 3CBA as the sole growth substrate, strain L6 demonstrated an increased oxygen affinity with decreasing steady-state oxygen concentrations.
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Our planet’s ecology and society are on a collision course, which manifests due to a contradiction in the assumptions of unlimited material growth fueling the linear economic paradigm. Our closed planetary ecosystem imposes confined amounts of space and a finite extent of resources upon its inhabitants. However, practically all the economic perspectives have been defiantly neglecting these realities, as resources are extracted, used and disposed of reluctantly (Ellen MacArthur Foundation 2015). The circular economy attempts to reconcile the extraction, production and usage of goods and resources with the limited availability of those resources and nature’s regenerative capabilities This perspective entails a shift throughout the supply chain, from material science (e g non-toxic, regenerative biomaterials) to novel logistical systems (e g low-carbon reverse logistics). Because of this, the circular economy is often celebrated for its potential environmental benefits and its usefulness as a blueprint for sustainable development (Ellen MacArthur Foundation 2017). Unfortunately, the promise of the circular economy aiming at enhanced sustainability through restorative intent and design (McDonough & Braungart 2010), is often inhibited by institutional barriers posed by the current linear economy of take, make, use and waste (Ghisellini et al. 2016). Underlying those barriers our cultural paradigm celebrates consumerism, exponential growth and financial benefit instead of human values such as diversity, care and trust. Based on a mapping exercise of the circular economy discourse in the Netherlands and an overview of international (academic) literature (Van den Berg 2020) supplemented with collaborative co-creation sessions, visiting events, conferences, giving talks and classes, we have defined a gap leading to the focus of the Professorship. First, we highlight the importance of a process approach in studying the transition from a linear to a circular economy, which is why we use the verb ‘entrepreneuring’ as it indicates the movement we collectively need to make. The majority of work in the field is based on start-ups and only captures snapshots while longitudinal and transition perspectives - especially of larger companies - are missing (Merli et al. 2019; Geissdoerfer et al. 2018; Bocken et al. 2014). We specifically adopt an entrepreneurship-as-practice lens (Thompson, Verduijn & Gartner 2020), which allows us to trace the doings – as opposed to only the sayings - of organizations involved in circular innovation. Such an approach also enables us to study cross-sector and interfirm collaboration, which is crucial to achieve ecosystem circularity (Raworth 2019). As materials flow between actors in a system, traditional views of ‘a value chain’ slowly make way for an ecosystem or value web perspective on ‘organizing business’. We summarize this first theme as ‘entrepreneurship as social change’ broadening dominant views of what economic activity is and who the main actors are supposed to be (Barinaga 2013; Calás, Smircich & Bourne 2009; Steyaert & Hjorth 2008; Nicholls 2008). Second, within the Circular Business Professorship value is a big word in two ways. First of all, we believe that a transition to a circular economy is not just a transition of materials, nor technologies - it is most of all a transition of values We are interested in how people can explore their own agency in transitioning to a circular economy thereby aligning their personal values with the values of the organization and the larger system they are a part of Second, while circularity is a broad concept that can be approached through different lenses, the way in which things are valued and how value is created and extracted lies at the heart of the transition (Mazzucato 2018). If we don’t understand value as collectively crafted it will be very hard to change things, which is why we specifically focus on multiplicity and co-creation in the process of reclaiming value, originating from an ethics of care Third, sustainability efforts are often concerned with optimization of the current – linear – system by means of ecoefficient practices that are a bit ‘less bad’; using ’less resources’, causing ‘less pollution’ and ‘having less negative impact’. In contrast, eco-effective practices are inherently good, departing from the notion of abundance: circular thinking celebrates the abundance of nature’s regenerative capacities as well as the abundance of our imagination to envision new realities (Ellen MacArthur Foundation 2015). Instead of exploiting natural resources, we should look closely in order to learn how we can build resilient self-sustaining ecosystems like the ones we find in nature. We are in need of rediscovering our profound connection with and appreciation of nature, which requires us to move beyond the cognitive and employ an aesthetic perspective of sustainability This perspective informs our approach to innovating education: aesthetics can support deep sustainability learning (Ivanaj, Poldner & Shrivastava 2014) and contribute to facilitating the circular change makers of the future. The current linear economy has driven our planet’s ecology and society towards a collision course and it is really now or never: if we don’t alter the course towards a circular economy today, then when? When will it become urgent enough for us to take action? Which disaster is needed for us to wake up? We desperately need substitutes for the current neo-liberal paradigm, which underlies our linear society and prevents us from becoming an economy of well-being In Entrepreneuring a regenerative society I propose three research themes – ‘entrepreneurship as social change’, ‘reclaiming value’ and ‘the aesthetics of sustainability’ – as alternative ways of embracing, studying and co-creating such a novel reality. LinkedIn: https://www.linkedin.com/in/kim-poldner-a003473/
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Multi-layer cell constructs produced in vitro are an innovative treatment option to support the growing demand for therapy in regenerative medicine. Our research introduces a novel construct integrating organ-derived decellularised extracellular matrix (dECM) hydrogels and 3D-printed biodegradable polymer meshes composed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) to support and maintain multiple layers of different cell types. We achieved that by integrating the mechanical stability of PHBV+P34HB, commonly used in the food storage industry, with a dECM hydrogel, which replicates organ stiffness and supports cellular survival and function. The construct was customised by adjusting the fibre arrangement and pore sizes, making it a suitable candidate for a personalised design. We showed that the polymer is degradable after precoating it with PHB depolymerase (PhaZ), with complete degradation achieved in 3–5 days and delayed by adding the hydrogel to 10 days, enabling tuneable degradation for regenerative medicine applications. Finally, as a proof of concept, we composed a three-layered tissue in vitro; each layer represented a different tissue type: epidermal, vascular, and subcutaneous layers. Possible future applications include wound healing and diabetic ulcer paths, personalised drug delivery systems, and personalised tissue implants.
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Chemical preservation is an important process that prevents foods, personal care products, woods and household products, such as paints and coatings, from undesirable change or decomposition by microbial growth. To date, many different chemical preservatives are commercially available, but they are also associated with health threats and severe negative environmental impact. The demand for novel, safe, and green chemical preservatives is growing, and this process is further accelerated by the European Green Deal. It is expected that by the year of 2050 (or even as soon as 2035), all preservatives that do not meet the ‘safe-by-design’ and ‘biodegradability’ criteria are banned from production and use. To meet these European goals, there is a large need for the development of green, circular, and bio-degradable antimicrobial compounds that can serve as alternatives for the currently available biocidals/ preservatives. Anthocyanins, derived from fruits and flowers, meet these sustainability goals. Furthermore, preliminary research at the Hanze University of Applied Science has confirmed the antimicrobial efficacy of rose and tulip anthocyanin extracts against an array of microbial species. Therefore, these molecules have the potential to serve as novel, sustainable chemical preservatives. In the current project we develop a strategy consisting of fractionation and state-of-the-art characterization methods of individual anthocyanins and subsequent in vitro screening to identify anthocyanin-molecules with potent antimicrobial efficacy for application in paints, coatings and other products. To our knowledge this is the first attempt that combines in-depth chemical characterization of individual anthocyanins in relation to their antimicrobial efficacy. Once developed, this strategy will allow us to single out anthocyanin molecules with antimicrobial properties and give us insight in structure-activity relations of individual anthocyanins. Our approach is the first step towards the development of anthocyanin molecules as novel, circular and biodegradable non-toxic plant-based preservatives.
Overusing non-degradable plastics causes a series of environmental issues, inferring a switch to biodegradable plastics. Polyhydroxyalkanoates (PHAs) are promising biodegradable plastics that can be produced by many microbes using various substrates from waste feedstock. However, the cost of PHAs production is higher compared to fossil-based plastics, impeding further industrial production and applications. To provide a guideline for reducing costs, the potential cheap waste feedstock for PHAs production have been summarized in this work. Besides, to increase the competitiveness of PHAs in the mainstream plastics economy, the influencing parameters of PHAs production have been discussed. The PHAs degradation has been reviewed related to the type of bacteria, their metabolic pathways/enzymes, and environmental conditions. Finally, the applications of PHAs in different fields have been presented and discussed to induce comprehension on the practical potentials of PHAs.
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Increasingly, entrepreneurial growth is discussed in relation to business sustainability and the wider questions of ‘growth’ – economic, green, or sustainable. This chapter will discuss the challenges and opportunities of teaching circular economy and Cradle to Cradle (C2C) models of sustainable production. The course applying circular economy theory to corporate case studies at the liberal arts college in The Netherlands will be discussed. Students were given the assignment to advise an existing company how to make a transition from a linear to circular economy model. https://doi.org/10.1108/978-1-78714-501-620171028 LinkedIn: https://www.linkedin.com/in/helenkopnina/
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