Browsing by Author "Wagland, Stuart"
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Item Open Access A decision support tool for enhanced landfill mining(Cranfield University, 2018-05-03 11:13) Coulon, Frederic; Wagland, Stuart; Griffiths, ZoeEnhanced Landfill Mining has great potential to reduce the negative effects of landfills on both the environment and human health, to reclaim valuable land and provide a new source of raw materials. However, uncertainties in economic feasibility and environmental and social outcomes act as a bottleneck to its widespread uptake. Here, we present a decision support tool which aims to reduce these uncertainties by assisting site operators in assessing the economic, environmental and social consequences of a proposed project, while also evaluating the best technology train to use and the amount of rare earth elements present. Such a tool is the first of its kind and we propose its use as an initial assessment aid prior to more complex modelling of project feasibility in order to increase the uptake of enhanced landfill mining practices in the field of sustainable waste management.Item Open Access Assessing metal recovery opportunities through bioleaching from past metallurgical sites and waste deposits: UK case study(CISA Publisher, 2022-12-31) Tezyapar Kara, Ipek; Marsay, Niall; Huntington, Victoria; Coulon, Frederic; Alamar, M. Carmen; Capstick, Michael; Higson, Stuart; Buchanan, Andrew; Wagland, StuartRecovery of metals from former industrial areas (also called brownfields) and closed landfill sites, are critical for future sustainable development and reducing the environmental risks they posed. In this study, the feasibility of using bioleaching for resource recovery of raw and secondary raw materials from a former metallurgical site and deposit (PMSD) located in the UK was investigated. Determination of the physicochemical parameters (conductivity, pH, moisture and ash content) that can affect bioleaching performance along with metal content analysis were carried out. Field measurement were also carried out using a portable X-ray fluorescence (pXRF) spectrometer as a rapid measurement tool and compared with the induced coupled mass spectrometry (ICP-MS) results. Fe (469,700 mg/kg), Ca (25,900 mg/kg) and Zn (14,600 mg/kg) were the most dominant elements present in the samples followed by Mn (8,600 mg/kg), Si (3,000 mg/kg) and Pb (2,400 mg/kg). The pXRF results demonstrated minimal variance (<10%) from the ICP-MS results. The preliminary assessment of bioleaching using Acidithiobacillus ferrooxidans at 5% pulp density with 22 g/L energy source and 10% (v/v) inoculum at pH 1.5 showed that 100% of Ti and Cu, 32% of Zn and 24% of Mn was recovered from the sample material, highlighting opportunities for the recovery of such metals through bioleaching processes.Item Open Access Assessing the opportunities of landfill mining as a source of critical raw materials in Europe(Eurowaste, 2017-10-16) Särkkä, H.; Kaartinen, T.; Hannus, Esa; Hirvonen, S.; Valjus, Tuire; Lerssi, J.; Dino, G. A.; Piergiorgio, R.; Griffiths, Zoe; Wagland, Stuart; Coulon, FredericMany of the metals in landfill constitute valuable and scarce natural resources. It has already been recognised that the recovery of these elements is critical for the sustainability of a number of industries. Arsenic (which is an essential part of the production of transistors and LEDs) is predicted to run out sometime in the next five to 50 years if consumption continues at the present rate. Nickel used for anything involving stainless steel and platinum group metals (PGMs) used in catalytic converters, fertilisers and others are also identified as critical materials (CM) to the EU economy at risk of depletion However, despite the increasing demand, none of this supply is supported by recycling. This is due to the high cost of recovery from low concentrations when compared to conventional mining. As demonstrated by the two pilot case studies of this study, mining landfill sites only for their metals content is not expected to be financially viable. However, other opportunities such as Waste-derived fuels from excavated materials exist which if combined , form the concept of ‘enhanced landfill mining’. have the potential to be highly energetic. The energy potential is comparable to the levels of energy of Refuse-Derived Fuels (RDF) produced from non-landfilled wastes.Item Open Access Bioleaching metal-bearing wastes and by-products for resource recovery: a review(Springer, 2023-05-22) Tezyapar Kara, Ipek; Kremser, k.; Wagland, Stuart; Coulon, FredericThe global transition to a circular economy calls for research and development on technologies facilitating sustainable resource recovery from wastes and by-products. Metal-bearing materials, including electronic wastes, tailings, and metallurgical by-products, are increasingly viewed as valuable resources, with some possessing comparable or superior quality to natural ores. Bioleaching, an eco-friendly and cost-effective alternative to conventional hydrometallurgical and pyrometallurgical methods, uses microorganisms and their metabolites to extract metals from unwanted metal-bearing materials. The performance of bioleaching is influenced by pH, solid concentration, energy source, agitation rate, irrigation rate, aeration rate, and inoculum concentration. Optimizing these parameters improves yields and encourages the wider application of bioleaching. Here, we review the microbial diversity and specific mechanisms of bioleaching for metal recovery. We describe the current operations and approaches of bioleaching at various scales and summarise the influence of a broad range of operational parameters. Finally, we address the primary challenges in scaling up bioleaching applications and propose an optimisation strategy for future bioleaching research.Item Open Access CORD_ASPEN Plus paper.xlsx(Cranfield University, 2020-03-19 11:39) Canopoli, Luisa; Coulon, Frederic; Wagland, StuartComplete dataset of ASPEN Plus modelling of pyrolysis of plastic wastes (polyethylene, PE, and polypropylene, PP) recovered from enhanced landfill mining. The ASPEN Plus simulation model was validated with published data and used for predicting possible outputs from the pyrolysis of excavated PE and PP. The model predicted oil yields within 4% error.Item Open Access CORD_Data paper_Pyrola.xlsx(Cranfield University, 2020-03-19 14:42) Canopoli, Luisa; Coulon, Frederic; Wagland, StuartComplete dataset of Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), which was used to analyse the pyrolysis decomposition products of 10 plastic samples made up of fresh and excavated samples of different ages from 4 MSW landfill sites. The samples included a single polymer for fresh and excavated polyethylene (PE) and polypropylene (PP), and two types of mixed excavated plastic materials, sample A (PE, PP, polystyrene (PS)) and sample B (PE, PP, PS, polyethylene terephthalate (PET), polyvinyl chloride (PVC)).Item Open Access Data file for Pyrola journal paper(Cranfield University, 2024-08-23) Wagland, Stuart; Coulon, FredericPyrolysis GC-MS testing of excavated landfilled plastics as part of an EPSRC-funded PhD project.Item Open Access Data for the paper "Degradation of excavated polyethylene and polypropylene waste from landfill"(Cranfield University, 2019-09-09 08:48) Wagland, Stuart; Coulon, Frederic; Canopoli, LuisaDegradation of excavated polyethylene and polypropylene waste from landfill, including composition and chemical characterisation.Item Open Access A decision support tool for enhanced landfill mining(CISA PUBLISHER an imprint of EUROWASTE Srl, 2018-03-31) Pastre, Guillaume; Griffiths, Zoe; Val, Javier; Tasiu, Abubakar Muhammad; Camacho-Dominguez, Erika Valeria; Wagland, Stuart; Coulon, FredericEnhanced Landfill Mining has great potential to reduce the negative effects of landfills on both the environment and human health, to reclaim valuable land and provide a new source of raw materials. However, uncertainties in economic feasibility and environmental and social outcomes act as a bottleneck to its widespread uptake. Here, we present a decision support tool (DST) which aims to reduce these uncertainties by assisting site operators in assessing the economic, environmental and social consequences of a proposed project, while also evaluating the best technology train to use and the amount of rare earth elements (REE) present. Such a tool is the first of its kind and we propose its use as an initial assessment aid prior to more complex modelling of project feasibility in order to increase the uptake of enhanced landfill mining practices in the field of sustainable waste management.Item Open Access Deoxygenation in anisole decomposition over bimetallic catalysts supported on HZSM-5(Elsevier, 2018-10-29) Zhang, Jiajun; Fidalgo, Beatriz; Wagland, Stuart; Shen, Dekui; Zhang, Xiaolei; Gu, SaiThis work investigated the deoxygenation reaction in anisole decomposition over HZSM-5 (HZ(25)) zeolite supported bimetallic catalysts to produce benzene, toluene and xylene (BTX). Experiments were performed in order to evaluate the synergistic effect between the two active metals with the focus on the effect of temperature, metal type, and metal loading ratio. Experimental results showed that 1%Ni-1%Mo/HZ(25) led to both the highest BTX yield (i.e. 30.0 wt%) and selectivity (i.e. 83.7%). On the contrary, bimetallic catalysts containing Fe were less effective in promoting the BTX production. It was identified that the optimum temperature for BTX production over 1%Ni-1%Mo/HZ(25) catalysts was 500 °C. Characterization of fresh and spent catalysts showed microcrystal particles of bi-metal loadings highly dispersed on the zeolite surface, and some agglomeration of metallic particles were also observed. Large amount of carbonaceous deposit was observed on the spent catalysts mainly in the form of amorphous. Density Functional Theory (DFT) modelling was carried out in order to study the adsorption energy of anisole and phenol molecules onto Ni-Mo, Ni-Fe and Mo-Fe surfaces; and the interactions between phenol molecule and bimetal surfaces were further analysed. All the analysed bimetal surfaces exhibited strong interactions with the adsorbed molecule. Ni-Mo surface declined electrons energy levels mainly around 1.5 eV in the adsorbate molecule and released the highest adsorption energy; while Ni-Fe and Mo-Fe surface led to more electrons exchange with the adsorbate during the adsorption. The modelling results agreed well with experiments by revealing that the strong binding between phenolic compounds (Phs) and the Ni-Mo based catalysts bimetal surface would lead to a higher BTX production in the deoxygenation reaction in the decomposition of anisole.Item Open Access Design and commissioning of a multi-mode prototype for thermochemical conversion of human faeces(Elsevier, 2018-03-23) Jurado Pontes, Nelia; Somorin, Tosin; Kolios, Athanasios J.; Wagland, Stuart; Patchigolla, Kumar; Fidalgo, Beatriz; Parker, Alison; McAdam, Ewan; Williams, Leon; Tyrrel, SeanThis article describes the design and commissioning of a micro-combustor for energy recovery from human faeces, which can operate both in updraft and downdraft modes. Energy recovery from faecal matter via thermochemical conversion has recently been identified as a feasible solution for sanitation problems in low income countries and locations of high income countries where access to sewage infrastructures is difficult or not possible. This technology can be applied to waterless toilets with the additional outcome of generating heat and power that can be used to pre-treat the faeces before their combustion and to ensure that the entire system is self-sustaining. The work presented here is framed within the Nano Membrane Toilet (NMT) project that is being carried out at Cranfield University, as part of the Reinvent the Toilet Challenge of the Bill and Melinda Gates Foundation. For this study, preliminary trials using simulant faeces pellets were first carried out to find out the optimum values for the main operating variables at the scale required by the process, i.e. a fuel flowrate between 0.4 and 1.2 g/min of dry faeces. Parameters such as ignition temperature, residence time, and maximum temperature reached, were determined and used for the final design of the bench-scale combustor prototype. The prototype was successfully commissioned and the first experimental results, using real human faeces, are discussed in the paper.Item Open Access Exploiting secondary raw materials from extractive waste facilities: A case study(Unknown, 2018-02-06) Dino, Giovanna Antonella; Rossetti, Piergiorgio; Lorenzi, Alessio; Mister, Ivan; Cazzaniga, Alberto; Coulon, Frederic; Griffiths, Zoe; Wagland, StuartIn recent years, resource scarcity has emphasised a need to transition from a linear to a circular flow of resources. Securing supplies of critical and secondary raw materials (CRM/SRM) for the manufacturing industry is at the forefront of industrial challenges, especially in Europe, USA and Asia. A key step towards achieving resource efficiency, is to recover these materials from anthropogenic waste deposits, such as urban landfill sites and extractive waste facilities. This means breaking away from the traditional linear use of resources to a closed-loop approach that allows maximum recovery of resources from waste. The management of extractive waste deposits and resource recovery is closely linked to the concept of urban mining. In this paper, we present a case study illustrating the feasibility of recovering SRM from EW facilities and discuss the pros and cons of undertaking such activities.Item Open Access The influence of humic acid on metal(loid)s leaching in landfill leachate for enhancing landfill mining(Elsevier, 2023-07-06) Lee, Hyeyeon; Coulon, Frederic; Wagland, StuartThe aim of this study was to investigate the effect of different concentrations of humic acid on the recovery rate of metal(loid)s in landfill leachate. The study focused on the release of 12 selected metal(loid)s, including critical raw materials (CRM) in landfills that were less than five years old and those that were more than ten years old. The experimental setup involved using different concentrations of humic acid (w/v) (0 %, 0.1 %, and 0.5 %) at pH 4 and 6. The results of the study showed that humic acid was effective in releasing Al, Cr, Co, Ni, Cu, Zn, As, Cd, and Pb. On the other hand, an increase in humic acid concentration led to a decrease in the release of Li, Mn, and Hg. The immobilization of Li, Mn, and Hg was due to the coordination and adsorption of humic acid. The presence of humic acid accelerated the release of metal(loid)s by carboxylic acidity compared to the recovery rate of metal(loid)s in landfill leachate without humic acid. However, a higher concentration of humic acid did not always result in a stronger recovery rate. The recovery rate of metal(loid)s was related to the solubility and concentration of humic acid. These findings can inform the development of more efficient and environmentally-friendly methods of recovering metal(loid)s using humic acid as a leaching agent.Item Open Access Influence of pH, depth and humic acid on metal and metalloids recovery from municipal solid waste landfills(Elsevier, 2021-09-15) Lee, Hyeyeon; Coulon, Frederic; Wagland, StuartThe recovery of metal(loid)s from municipal solid waste (MSW) samples <10 years old and >10 years old was investigated using a series of pH-dependence leaching batch tests ranging between pH 2 and 10. Further to this, the influences of various parameters, including depth, and humic acid (HA) concentrations on the recovery of metal(loid)s including Li, Al, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Pb, and Hg were investigated. The Visual MINTEQ geochemical software was then used to model the metal(loid)s release in the presence of different HA concentrations ranging from 28 mg/L to 100 mg/L, which can be found in landfill sites and pH ranging from 2 to 10. The results showed that the release amount of Li, Al, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Pb, and Hg are in the range of 0.03–0.14 mg/L, 0.65–83.33 mg/L, 0.01–0.19 mg/L, 0.18–18.17 mg/L, 0.01–0.09 mg/L, 0.06–0.38 mg/L, 0.12–5.2 mg/L, 0.14–11.57 mg/L, 0.02–0.10 mg/L, 0.00–26.17 mg/L, 0.03–25.17 mg/L, and 0.00–0.01 mg/L with deionised water as leachant at different pH. The release amount of HA was relatively increased from 0 to 2% in 48–55 m compared to 3–9 m in the MSW landfill. HA can promote the leaching rate of metals with an appropriate amount. Base on the study results, the optimal condition of leaching metals was pH 2, and HA 28 mg/L at less than 10 m depth. The high concentration of metals in landfill leachate may be enhanced to effectively recover metals as the critical challenge of recovering metals from leachate is the low concentration of metals. Thus, the information can be useful for economically feasible in the recovery of metals.Item Open Access Investigation of municipal solid waste (MSW) and industrial landfills as a potential source of secondary raw materials(Cranfield University, 2018-05-03 12:32) Coulon, Frederic; Wagland, Stuart; Griffiths, Zoein-depth characterisation of a number of selected municipal and industrial landfill pilot sites as well as mining disposal sites have been assessed for enhanced landfill mining opportunitiesItem Open Access Iron and nitrogen co-doping biochar for simultaneous and efficient adsorption of oxytetracycline and norfloxacin from wastewater(Elsevier, 2025-04-01) Cheng, Xiaoxue; Jiang, Ding; Zhu, Weiyi; Xu, Huan; Ling, Qifan; Yang, Jingwen; Wang, Xinyu; Zhang, Kexin; Zheng, Xiaolong; He, Sirong; Cao, Bin; Wagland, Stuart; Wang, ShuangThe global proliferation of antimicrobial resistance (AMR) poses a critical challenge to environmental and public health, driven by excessive antibiotic release from medical, agricultural, and aquaculture activities. This study investigates the synthesis and application of Fe/N-doped biochar derived from Enteromorpha clathrata (EC) for the removal of oxytetracycline (OTC) and norfloxacin (NOR) from water. The biochar, synthesized via pyrolysis and NaOH activation, was characterized by BET, SEM, and XPS analyses, revealing a porous structure with enriched functional groups. The EC-derived biochar demonstrated high adsorption capacities for OTC (625.325 mg·g⁻1) and NOR (487.379 mg·g⁻1) under neutral pH conditions, with adsorption following Langmuir and pseudo-second-order models, indicative of monolayer chemisorption. The biochar also exhibited excellent reusability, supporting practical applications. The strong interactions between the FeN4 active sites and the antibiotics were quantified through DFT calculations, showing binding energies of −394.91 kcal/mol for NOR and −398.10 kcal/mol for OTC, highlighting the important role of FeN4 in facilitating efficient adsorption. Additionally, density of states (DOS) analysis revealed that formation of Fe-N/O chemical bonds was confirmed through the hybridization of Fe 3d orbitals with N/O 2p orbitals. Overall, Fe/N-rich biochar contributes to its potential for practical applications in antibiotic removal from aqueous systems.Item Open Access Landfill mining from extractive waste facilities: The importance of a correct site characterisation and evaluation of the potentialities. A case study from Italy(Elsevier, 2018-05-01) Dino, Giovanna Antonella; Rossetti, Piergiorgio; Perotti, Luigi; Alberto, Walter; Sarkka, Heikki; Coulon, Frederic; Wagland, Stuart; Griffiths, Zoe; Rodeghiero, FrancoRaw materials (RM) and critical raw materials (CRM; EC, 2017) supply is essential to both the maintenance and development of the EU economy as its industries rely on a steady RM supply. Thus, securing a sustainable RM and CRM supply and their circular use in the economy is of importance at EU level and beyond (Blengini et al., 2017, Coulomb et al., 2015, Vidal-Legaz et al., 2016). Furthermore, the developments of clean technologies coupled with economic growth exacerbate the short and long-term demand and needs (Blagoeva et al., 2016, Pavel and Tzimas, 2016). For example, Habib and Wenzel (2014) reported that the necessary supply Nd and Dy will grow from 10.0 Gg to 54.5 Gg and 0.5 Gg to 4.95 Gg respectively from 2010 to 2050.Item Open Access Landfill mining report_2016.pdf(Cranfield University, 2017-04-21 11:46) Canopoli, Luisa; Wagland, Stuart; Coulon, FredericAn era of rising consumption has led to resource scarcity across major industries. One way to overcome this challenge and ascertain future supply of resources is recovery of landfilled material. This so-called landfilled mining may valorise previously discarded material streams for a number of purposes and contribute to a circular economy. Across England and Wales, there are more than 20,000 landfill sites of which 90% have been closed before 1996. Besides the general belief that valuable resources can be found within landfills, mining the waste has a number of additional benefits. One stems from the fact that they often lack modern environmental protection technology, which may lead to negative environmental and health impacts. The combination of these facts poses an interesting opportunity for combined resource-recovery and remediation strategies. The report at hand is in place to assess viability and feasibility of landfill mining processes across England and Wales in a step-wise approachItem Open Access Metal(loid)s concentration with humic acid in <1 and >10 year old landfills(Cranfield University, 2023-03-21 08:43) Wagland, Stuart; Lee, Hyeyeon; Coulon, FredericMetal(loid)s mobilised from landfill samples at differing pH and humic acid concentrations. The datasets provide metal(loid) concentrations for samples 10 years old.Item Open Access Recovering metal(loids) and rare earth elements from closed landfill sites without excavation: leachate recirculation opportunities and challenges(Elsevier, 2021-12-27) Lee, Hyeyeon; Coulon, Frederic; Beriro, D. J.; Wagland, StuartMetal (loids) and Rare Earth Elements (REE) (‘metals’) are used in a wide range of products, and therefore, the improvement of expectations for everyday comforts with demand continues to grow. Metal-bearing wastes are a secondary source of raw material that can meet this demand by providing a previously unconsidered low impact supply source. Total annual leachate production is 1,056,716 m3. Therefore, landfill leachate emerges as a significant potential resource as it contains high concentrations of metals. However, realising a profitable return on investment for leachate processing is a challenge due to relatively low recovery rates of approximately 0.02% of total heavy metals in a landfill being leached out in 30 years. Variation within the multi-element value and the effect of other chemicals in these complex mixtures. There is a need to better understand the mechanisms and potential applicability of extraction methods for optimising metals recovery from leachate. This paper addresses this need by providing a systematic review of the critical factors and environmental conditions that influence the behaviour of metals within the landfilled waste. The paper provides a synthesis of how the factors and conditions may affect leachate recirculation efficiency for recovery in the context of a range of opportunities and challenges facing circular economy practitioners. To approach feasibility metal recovery economically from landfill leachate without energy-intensive and environmentally destructive, future research actions need to be initiated in lab-based and later on semi-pilot to pilot studies, which the review can help achieve the challenges.