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Featured researches published by Costas A. Velis.


Waste Management & Research | 2012

An analytical framework and tool (‘InteRa’) for integrating the informal recycling sector in waste and resource management systems in developing countries

Costas A. Velis; David C. Wilson; Ondina Rocca; Stephen R. Smith; Antonis Mavropoulos; C.R. Cheeseman

In low- and middle-income developing countries, the informal (collection and) recycling sector (here abbreviated IRS) is an important, but often unrecognised, part of a city’s solid waste and resources management system. Recent evidence shows recycling rates of 20–30% achieved by IRS systems, reducing collection and disposal costs. They play a vital role in the value chain by reprocessing waste into secondary raw materials, providing a livelihood to around 0.5% of urban populations. However, persisting factual and perceived problems are associated with IRS (waste-picking): occupational and public health and safety (H&S), child labour, uncontrolled pollution, untaxed activities, crime and political collusion. Increasingly, incorporating IRS as a legitimate stakeholder and functional part of solid waste management (SWM) is attempted, further building recycling rates in an affordable way while also addressing the negatives. Based on a literature review and a practitioner’s workshop, here we develop a systematic framework—or typology—for classifying and analysing possible interventions to promote the integration of IRS in a city’s SWM system. Three primary interfaces are identified: between the IRS and the SWM system, the materials and value chain, and society as a whole; underlain by a fourth, which is focused on organisation and empowerment. To maximise the potential for success, IRS integration/inclusion/formalisation initiatives should consider all four categories in a balanced way and pay increased attention to their interdependencies, which are central to success, including specific actions, such as the IRS having access to source separated waste. A novel rapid evaluation and visualisation tool is presented—integration radar (diagram) or InterRa—aimed at illustrating the degree to which a planned or existing intervention considers each of the four categories. The tool is further demonstrated by application to 10 cases around the world, including a step-by-step guide.


Waste Management | 2015

'Wasteaware' benchmark indicators for integrated sustainable waste management in cities

David C. Wilson; Ljiljana Rodic; Michael J. Cowing; Costas A. Velis; Andrew Whiteman; Anne Scheinberg; Recaredo Vilches; Darragh Masterson; Joachim Stretz; Barbara Oelz

This paper addresses a major problem in international solid waste management, which is twofold: a lack of data, and a lack of consistent data to allow comparison between cities. The paper presents an indicator set for integrated sustainable waste management (ISWM) in cities both North and South, to allow benchmarking of a citys performance, comparing cities and monitoring developments over time. It builds on pioneering work for UN-Habitats solid waste management in the Worlds cities. The comprehensive analytical framework of a citys solid waste management system is divided into two overlapping triangles - one comprising the three physical components, i.e. collection, recycling, and disposal, and the other comprising three governance aspects, i.e. inclusivity; financial sustainability; and sound institutions and proactive policies. The indicator set includes essential quantitative indicators as well as qualitative composite indicators. This updated and revised Wasteaware set of ISWM benchmark indicators is the cumulative result of testing various prototypes in more than 50 cities around the world. This experience confirms the utility of indicators in allowing comprehensive performance measurement and comparison of both hard physical components and soft governance aspects; and in prioritising next steps in developing a citys solid waste management system, by identifying both local strengths that can be built on and weak points to be addressed. The Wasteaware ISWM indicators are applicable to a broad range of cities with very different levels of income and solid waste management practices. Their wide application as a standard methodology will help to fill the historical data gap.


Journal of Hazardous Materials | 2018

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

John N. Hahladakis; Costas A. Velis; Roland Weber; Eleni Iacovidou; Phil Purnell

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.


Waste Management & Research | 2013

Waste management and recycling in the former Soviet Union: The City of Bishkek, Kyrgyz Republic (Kyrgyzstan)

Natasha M Sim; David C. Wilson; Costas A. Velis; Stephen R. Smith

The UN-Habitat Integrated Sustainable Waste Management (ISWM) benchmarking methodology was applied to profile the physical and governance features of municipal solid waste (MSW) management in the former Soviet Union city of Bishkek, capital of the Kyrgyz Republic. Most of the ISWM indicators were in the expected range for a low-income city when compared with 20 reference cities. Approximately 240,000 t yr-1 of MSW is generated in Bishkek (equivalent to 200 kg capita-1 yr-1); collection coverage is over 80% and 90% of waste disposed goes to semi-controlled sites operating with minimal environmental standards. The waste composition was a distinctive feature, with relatively high paper content (20–27% wt.) and intermediate organic content (30–40% wt.). The study provides the first quantitative estimates of informal sector recycling, which is currently unrecognised by the city authorities. Approximately 18% wt. of generated MSW is recycled, representing an estimated annual saving to the city authorities of US


Royal Society Open Science | 2017

Challenges and opportunities associated with waste management in India

Sunil Kumar; Stephen R. Smith; Geoff Fowler; Costas A. Velis; S. Jyoti Kumar; Shashi Kiran Arya; Rena; Rakesh Kumar; Christopher R. Cheeseman

0.7–1.1 million in avoided collection/disposal costs. The waste management system is controlled by a centralised municipal waste enterprise (Tazalyk); therefore, institutional coherence is high relative to lower-middle and low-income cities. However, performance on other governance factors, such as inclusivity and financial sustainability, is variable. Future priorities in Bishkek include extending collection to unserved communities; improving landfill standards; increasing recycling rates through informal sector cooperation; improving data availability; and engaging all stakeholders in waste management strategy decisions. Extending the scope and flexibility of the ISWM protocol is recommended to better represent the variation in conditions that occur in waste management systems in practice.


Science of The Total Environment | 2018

Fully integrated modelling for sustainability assessment of resource recovery from waste

Joel Millward-Hopkins; Jonathan Busch; Phil Purnell; Oliver Zwirner; Costas A. Velis; Andy Brown; John N. Hahladakis; Eleni Iacovidou

India faces major environmental challenges associated with waste generation and inadequate waste collection, transport, treatment and disposal. Current systems in India cannot cope with the volumes of waste generated by an increasing urban population, and this impacts on the environment and public health. The challenges and barriers are significant, but so are the opportunities. This paper reports on an international seminar on ‘Sustainable solid waste management for cities: opportunities in South Asian Association for Regional Cooperation (SAARC) countries’ organized by the Council of Scientific and Industrial Research-National Environmental Engineering Research Institute and the Royal Society. A priority is to move from reliance on waste dumps that offer no environmental protection, to waste management systems that retain useful resources within the economy. Waste segregation at source and use of specialized waste processing facilities to separate recyclable materials has a key role. Disposal of residual waste after extraction of material resources needs engineered landfill sites and/or investment in waste-to-energy facilities. The potential for energy generation from landfill via methane extraction or thermal treatment is a major opportunity, but a key barrier is the shortage of qualified engineers and environmental professionals with the experience to deliver improved waste management systems in India.


Waste Management | 2017

Technical properties of biomass and solid recovered fuel (SRF) co-fired with coal: Impact on multi-dimensional resource recovery value

Eleni Iacovidou; John N. Hahladakis; Innes Deans; Costas A. Velis; Phil Purnell

This paper presents an integrated modelling approach for value assessments, focusing on resource recovery from waste. The method tracks and forecasts a range of values across environmental, social, economic and technical domains by attaching these to material-flows, thus building upon and integrating unidimensional models such as material flow analysis (MFA) and lifecycle assessment (LCA). We argue that the usual classification of metrics into these separate domains is useful for interpreting the outputs of multidimensional assessments, but unnecessary for modelling. We thus suggest that multidimensional assessments can be better performed by integrating the calculation methods of unidimensional models rather than their outputs. To achieve this, we propose a new metric typology that forms the foundation of a multidimensional model. This enables dynamic simulations to be performed with material-flows (or values in any domain) driven by changes in value in other domains. We then apply the model in an illustrative case highlighting links between the UK coal-based electricity-production and concrete/cement industries, investigating potential impacts that may follow the increased use of low-carbon fuels (biomass and solid recovered fuels; SRF) in the former. We explore synergies and trade-offs in value across domains and regions, e.g. how changes in carbon emissions in one part of the system may affect mortality elsewhere. This highlights the advantages of recognising complex system dynamics and making high-level inferences of their effects, even when rigorous analysis is not possible. We also indicate how changes in social, environmental and economic values can be understood as being driven by changes in the technical value of resources. Our work thus emphasises the advantages of building fully integrated models to inform conventional sustainability assessments, rather than applying hybrid approaches that integrate outputs from parallel models. The approach we present demonstrates that this is feasible and lays the foundations for such an integrated model.


Waste Management | 2018

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

John N. Hahladakis; Phil Purnell; Eleni Iacovidou; Costas A. Velis; Maryann Atseyinku

The power plant sector is adopting the co-firing of biomass and solid recovered fuel (SRF) with coal in an effort to reduce its environmental impact and costs. Whereas this intervention contributes to reducing carbon emissions and those of other pollutants related with the burning of fossil fuel, it may also result in hidden impacts that are often overlooked. When co-firing, the physical and chemical properties of the mixed fuels and the subsequent technical implications on the process performance and by-products are significant. Interconnections between multiple values nested within four domains of value, i.e. environmental, economic, technical and social, mean that changes in the one domain (in the co-firing case, the technical one) can have considerable implications in the other domains as well. In this study, using a systematic and flexible approach to conceptualising multi-dimensional aspects associated with the co-firing of biomass and SRF with coal, we unveil examples of such interconnections and implications on overall value delivered through the use and recovery of waste resources. Such an analysis could underpin the selection of useful metrics (quantitative or semi-quantitative descriptors) for enabling a systemic multi-dimensional value assessment, and values distribution amongst interconnected parts of resource recovery systems; key in enabling sound analysis and decision-making.


Habitat International | 2006

Role of informal sector recycling in waste management in developing countries

David C. Wilson; Costas A. Velis; C.R. Cheeseman

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 (141u202fkt) was finally sent to reprocessors (22u202fkt); (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.


Proceedings of the Institution of Civil Engineers - Waste and Resource Management | 2013

Integrated sustainable waste management in developing countries

David C. Wilson; Costas A. Velis; Ljiljana Rodic

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John N. Hahladakis

Technical University of Crete

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