16 research outputs found

    Post-consumer plastic packaging waste in England: Assessing the yield of multiple collection-recycling schemes

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    The European Commission (EC) recently introduced a ‘Circular Economy Package’, setting ambitious recycling targets and identifying waste plastics as a priority sector where major improvements are necessary. Here, the authors explain how different collection modalities affect the quantity and quality of recycling, using recent empirical data on household (HH) post-consumer plastic packaging waste (PCPP) collected for recycling in the devolved administration of England over the quarterly period July-September 2014. Three main collection schemes, as currently implemented in England, were taken into account: (i) kerbside collection (KS), (ii) household waste recycling centres (HWRCs) (also known as ‘civic amenity sites’), and (iii) bring sites/banks (BSs). The results indicated that: (a) the contribution of KS collection scheme in recovering packaging plastics is higher than HWRCs and BBs, with respective percentages by weight (wt%) 90%, 9% and 1%; (b) alternate weekly collection (AWC) of plastic recyclables in wheeled bins, when collected commingled, demonstrated higher yield in KS collection; (c) only a small percentage (16%) of the total amount of post-consumer plastics collected in the examined period (141 kt) was finally sent to reprocessors (22 kt); (c) nearly a third of Local Authorities (LAs) reported insufficient or poor data; and (d) the most abundant fractions of plastics that finally reached the reprocessors were mixed plastic bottles and mixed plastics

    Designing Products for the Circular Economy

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    Until recent years, apparel product design has been undertaken with very little reference to environmental sustainability. However, the legislative framework has increasingly constrained design decisions relating to the use of hazardous chemicals, especially with the advent of REACH regulations within the EU. Most companies now recognise a large number of chemical substances that are prohibited in the dyeing and finishing of textiles. This dominates thinking about design for the environment. The increasing adoption of environmental management systems has expanded the vision for initiatives promoting sustainability, including laundering and care. Principles are recognised for product design and development that lead to more sustainable goods and services. In some industries, regulations require producer to take responsibility for the disposal of products companies release to the market. This obligation has triggered thinking about design for disassembly and design for disposal. This development has accelerated the adoption of circular economy concepts. The EU has not implemented producer responsibility in apparel, although some companies have voluntarily championed circular economy initiatives. However, the business models of most apparel companies have nothing to say about end-of-life issues. This chapter is concerned with new product development processes that incorporate Design for Environment and Design for Disassembly and Disposal. As there are numerous technical issues to address, a team-based product development process has many advantages, whereby garment designers work alongside specialists from other disciplines. This process requires culture change to be embraced by most brand owners, and a departure from the practice of separating the design process from the product development process. In most cases, changes of this nature bring disruption to a globalised industrial sector. Case studies will be considered that illustrate the concepts developed in this chapter. In particular, the French experience of adopting producer responsibility for apparel goods is considered. The accredited organisation ECO TLC exhibits strength in the promotion of sustainability projects, but there is a fundamental weakness in that culture change in the design process of brand owners is hard to discern

    Up-Cycling Waste Glass to Minimal Water Adsorption/Absorption Lightweight Aggregate by Rapid Low Temperature Sintering: Optimization by Dual Process-Mixture Response Surface Methodology

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    Mixed color waste glass extracted from municipal solid waste is either not recycled, in which case it is an environmental and financial liability, or it is used in relatively low value applications such as normal weight aggregate. Here, we report on converting it into a novel glass-ceramic lightweight aggregate (LWA), potentially suitable for high added value applications in structural concrete (upcycling). The artificial LWA particles were formed by rapidly sintering (<10 min) waste glass powder with clay mixes using sodium silicate as binder and borate salt as flux. Composition and processing were optimized using response surface methodology (RSM) modeling, and specifically (i) a combined process-mixture dual RSM, and (ii) multiobjective optimization functions. The optimization considered raw materials and energy costs. Mineralogical and physical transformations occur during sintering and a cellular vesicular glass-ceramic composite microstructure is formed, with strong correlations existing between bloating/shrinkage during sintering, density and water adsorption/absorption. The diametrical expansion could be effectively modeled via the RSM and controlled to meet a wide range of specifications; here we optimized for LWA structural concrete. The optimally designed LWA is sintered in comparatively low temperatures (825-835 °C), thus potentially saving costs and lowering emissions; it had exceptionally low water adsorption/absorption (6.1-7.2% w/wd; optimization target: 1.5-7.5% w/wd); while remaining substantially lightweight (density: 1.24-1.28 g.cm-3; target: 0.9-1.3 g.cm-3). This is a considerable advancement for designing effective environmentally friendly lightweight concrete constructions, and boosting resource efficiency of waste glass flows

    Oil-Based Mud Cutting as an Additional Raw Material in Clinker Production

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    Oil-Based Mud (OBM) cutting is a hazardous by-product generated during oil-well drilling. Its chemical composition suggests that it might be suitable as a raw material in cement manufacturing. It is rich in calcium oxide, silica, and aluminium oxide, which are the major oxides in raw materials for cement manufacturing. In this research, OBM cutting is used as a constituent of the raw meal for cement clinker production. Raw meal mixtures were prepared by mixing different ratios of raw materials increasing OBM content. The impact of the addition of OBM cutting on the resulting clinker has been investigated. The results demonstrate that OBM cutting could be recycled in the manufacturing of Portland cement clinker. Clinker prepared using OBM cutting had very similar properties to that prepared from limestone. This result could represent an opportunity for solving an environmental problem. The addition of OBM cutting lowers the calcination temperature, and increases the rate of carbonate dissociation. However, it also leads to a higher free lime in clinker, which is a result of the presence of trace elements, such as barium. Overall, its use as a raw material in cement production could provide a cost-effective, environment-friendly route for the management of OBM cutting

    An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling

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    Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised the demand for plastic materials that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as “additives”) contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclates. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times

    Metrics for optimising the multi-dimensional value of resources recovered from waste in a circular economy: A critical review

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    © 2017 The Authors - Established assessment methods focusing on resource recovery from waste within a circular economy context consider few or even a single domain/s of value, i.e. environmental, economic, social and technical domains. This partial approach often delivers misleading messages for policy- and decision-makers. It fails to accurately represent systems complexity, and obscures impacts, trade-offs and problem shifting that resource recovery processes or systems intended to promote circular economy may cause. Here, we challenge such partial approaches by critically reviewing the existing suite of environmental, economic, social and technical metrics that have been regularly observed and used in waste management and resource recovery systems' assessment studies, upstream and downstream of the point where waste is generated. We assess the potential of those metrics to evaluate ‘complex value’ of materials, components and products, i.e., the holistic sum of their environmental, economic, social and technical benefits and impacts across the system. Findings suggest that the way resource recovery systems are assessed and evaluated require simplicity, yet must retain a suitable minimum level of detail across all domains of value, which is pivotal for enabling sound decision-making processes. Criteria for defining a suitable set of metrics for assessing resource recovery from waste require them to be simple, transparent and easy to measure, and be both system- and stakeholder-specific. Future developments must focus on providing a framework for the selection of metrics that accurately describe (or at least reliably proxy for) benefits and impacts across all domains of value, enabling effective and transparent analysis of resource recovery form waste in circular economy systems.We gratefully acknowledge support of the UK Natural Environ-ment Research Council (NERC) and the UK Economic and SocialResearch Council (ESRC) who funded this work in the context of‘Complex Value Optimisation for Resource Recovery’(CVORR)project (Grant No. NE/L014149/1)

    Summary ouput data - Wasteaware Cities Benchmark Indicators - WABI 2023 - Global data analytics - Machine learning vs. Non-linear Regression

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    This is the output dataset for the research publication "Socio-economic development drives solid waste management performance in cities: A global analysis using machine learning". It features Metadata info used by R codes Summary of results for two modelling approaches (machine learning: Conditional random-forest and non-linear regression) The independent variables dataset analysed here refer to specific indicators of the WABI methodology (https://www.sciencedirect.com/science/article/pii/S0956053X14004905) that generates solid waste management and resource recovery profiles for cities. It was applied here for 40 cities around the world. The data input are available here: 10.5281/zenodo.7570174We are grateful to UN-Habitat for funding the work on the initial version of the indicators, including 20 city profiles, and GIZ through their 'Operator Models' project which funded an intermediate version of the indicators and a further 5 city profiles. We acknowledge all the profilers of the individual cities – many are named in Table S2, and others in reference (Scheinberg et al. 2010). We thank past MSc students under the authors' supervision for offering preliminary partial data clearing and commentary: Henry Hickman (MSc dissertation at University of Leeds, supervised by C.A.V and D.C.W.) and Margaux Fargier (Final year MEng dissertation at Imperial College London, supervised by S.M.G, D.C.W and C.A.V.). We are grateful to Dr Josh Cottom and Mr Ed Cook at the University of Leeds for input on the GDP version selection. We acknowledge the support of Dr Ljiljana Rodic for contributing in data quality control

    Medical and healthcare waste generation, storage, treatment and disposal: a systematic scoping review of risks to occupational and public health

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    Systems to safely store, handle, treat and dispose of medical (healthcare) waste are well developed in the 21st century. Yet, across many parts of the Global South (low-income and middle-income countries) such systems, resources and knowhow are lacking; to the extent that medical waste could pose a serious threat to the health, safety and lives of millions of healthcare workers and waste handlers who frequently interact with this category of materials. We present here a novel scope and dimension to investigating specifically the risks and hazards to people who come into contact with medical waste, focusing on activity types and established medical practice. A systematic scoping review of evidence (PRISMA-Scr) was used to critically analyze, compare and summarize data. Prevalent combinations of hazards, exposure and risk are semi-quantitatively scored and ranked. Our results signpost three core topics posing a major risk to human health: (1) Open, uncontrolled burning and rudimentary incineration of medical waste by waste handlers who have to make difficult choices between burning or discarding on land (e.g. in dumpsites) from where it risks pathogen infection; (2) A small but non-negligible trade in reused medical equipment (e.g. hypodermic needles), proliferated by a cohort of waste reclamation specialists (sub-group of waste pickers); and (3) The mismanagement of medical sharps at the point of generation, handling and storage in the Global North and South. A combination of immediate action and further research are recommended to address and inform on these topics which threaten the health and mortality of millions. </p
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