CERES :: Browsing by Author "Coulon, Frederic"

Browsing by Author "Coulon, Frederic"

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Open Access
A decision support tool for enhanced landfill mining
(Cranfield University, 2018-05-03 11:13) Coulon, Frederic; Wagland, Stuart; Griffiths, Zoe
Enhanced 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.
Open Access
Adsorption behaviour of 1,3,5-trinitroperhydro-1,3,5-triazine, 2,4-dinitroanisole and 3-nitro-1,2,4-triazol-5-one on commercial activated carbons
(Elsevier, 2020-04-30) Fawcett-Hirst, William; Temple, Tracey J.; Ladyman, Melissa K.; Coulon, Frederic
Insensitive high explosives are increasingly being used to replace more sensitive formulations, however large quantities of environmentally hazardous wastewater are generated from loading, assembling and packing processes. Currently, there is limited literature regarding the treatment of wastewater contaminated with these hazardous insensitive high explosive materials such as 1,3,5-trinitroperhydro- 1,3,5-triazine (RDX), 2,4-dinitoranisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO). The preferred method of explosive wastewater treatment is adsorption by activated carbon, usually through treatment columns or fluidised beds that are simple to operate and cost effective. The aim of this research was to assess whether commercially available activated carbons would be suitable and economically viable to treat explosive wastewater containing RDX, DNAN and NTO. Bottle point tests were used to determine adsorption capacity and adsorption kinetics for the individual insensitive high explosives with three different activated carbons. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherms to determine the mechanisms of adsorption. Six hour bottle point tests for a mixture of the three insensitive high explosive constituents were used to consider possible preferential adsorption. As expected, RDX and DNAN were adsorbed at concentrations up to 40 mg.L-1 and 150 mg.L-1 respectively by the activated carbons tested, demonstrating the viability of treatment by adsorption. However, at the high concentrations of NTO expected in wastewater (1400 mg.L-1) activated carbons were rapidly saturated, suggesting that treatment of NTO contaminated wastewater would require prohibitively large quantities of activated carbon compared to RDX and DNAN.
Open Access
Advancing biosensing techniques for detection of antimicrobial resistance genes and antibiotics in water
(Cranfield University, 2024-09) Li, Wenliang; Yang, Zhugen; Coulon, Frederic
Antimicrobial resistance (AMR) poses a significant global public health threat requiring urgent attention for surveillance of antibiotic resistance genes (ARGs) and antibiotics in the environment. In this PhD study, a real-time fluorescent detection assay of antimicrobial resistance genes (ARGs) was developed to specifically target two key ARGs, tet(M) and tet(x3) to detect tetracycline and tigecycline resistance respectively in water samples. Additionally, crassphage gene was investigated for anthropogenic activities since they also play a vital role in the AMR transmission. The advanced ARG detection assay was based on multiplexing recombinase polymerase amplification (RPA) and subsequent sequence-specific recognition by the trans-cleavage activity of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas12a. The assay achieved limits of detection (LODs) of 1 copy µL⁻¹ for all three gene targets with an accuracy of 100% in spiked tap and surface water samples. Expanding the assay by including two additional end-point detection modalities, lateral flow assay (LFA) and voltametric detection, further demonstrate its versatility. LODs of 1 copy µL⁻¹ for tet(x3) and crassphage, and 10 copies µL⁻¹ for tet(M) (LFA) and 10 copies µL⁻¹ for all three targets (electrochemical) were reached. Validation against gold standard quantitative polymerase chain reaction (qPCR) using real water samples, including wastewater and drinking water samples, revealed a remarkable 100% accuracy rate. Antibiotics detection assay was conceptualised based on the amplification of hybridisation chain reaction (HCR) followed by CRISPR/Cas mediated cleavage within a DNA hydrogel matrix. This approach aimed to release electroactive methylene blue (MB) particles, detectable and quantifiable by square wave voltammetry (SWV). While unforeseen circumstances impeded full assay development, the preliminary data illustrated the viability of the proposed method, suggesting avenues for further research to develop rapid and onsite antibiotics detection methods.
Open Access
Advancing the development and application of decision support systems for sustainable brownfield redevelopment.
(Cranfield University, 2023-12) Hammond, Ellis Bernard; Coulon, Frederic; Hallett, Stephen; Beriro, Darren
The redevelopment of brownfield sites is a vital part of ensuring sustainable urban development but has a range of challenges, including contamination and/or geotechnical hazards, leading to risk and cost implications. Brownfield redevelopment involves multiple stakeholders, from land use planners, land developers, and specialist consultants, to local community groups, and neighbouring residents. Understanding complex data and information can be difficult for decision-makers, which is exacerbated when communicating development scenarios and options with others. To support stakeholders, digital tools are often used, including specialised Decision Support Systems (DSSs). This PhD research investigates and contributes to the advancement of brownfield redevelopment DSSs. Existing and emerging challenges are evaluated, identifying improvement opportunities through a critical review of literature and large-scale sector- wide stakeholder consultation. A novel WebGIS-based DSS was developed in collaboration with land use planning stakeholders, applying the DSS to an area of post- industrial land within the Liverpool city region, UK. The DSS was evaluated through user testing, where improvements were identified and implemented, and verified, using a combination of empirical and user-testing methods. Overall, the approach and application of this PhD research demonstrates modern user led DSS development for brownfield applications, overcoming many of the limitations of existing work. The use of the DSS to support early-stage planning and redevelopment of brownfield land is aligned with and informs, multiple current policies for sustainable development and the use of applied digital technologies in planning and land development.
Open Access
Aged-engineered nanoparticles effect on sludge anaerobic digestion performance and associated microbial communities
(Elsevier, 2017-07-23) Eduok, Samuel; Ferguson, Robert M. W.; Jefferson, Bruce; Villa, Raffaella; Coulon, Frederic
To investigate the potential effect of aged engineered nanoparticles (a-ENPs) on sludge digestion performance, 150 L pilot anaerobic digesters (AD) were fed with a blend of primary and waste activated sludge spiked either with a mixture of silver oxide, titanium dioxide and zinc oxide or a mixture of their equivalent bulk metal salts to achieve a target concentration of 250, 2000, and 2800 mg kg− 1 dry weight, respectively. Volatile fatty acids (VFA) were 1.2 times higher in the spiked digesters and significantly different (p = 0.05) from the control conditions. Specifically, isovaleric acid concentration was 2 times lower in the control digester compared to the spiked digesters, whereas hydrogen sulfide was 2 times lower in the ENPs spiked digester indicating inhibitory effect on sulfate reducing microorganisms. Based on the ether-linked isoprenoids concentration, the total abundance of methanogens was 1.4 times lower in the ENPs spiked digester than in the control and metal salt spiked digesters. Pyrosequencing indicated 80% decrease in abundance and diversity of methanogens in ENPs spiked digester compared to the control digester. Methanosarcina acetivorans and Methanosarcina barkeri were identified as nano-tolerant as their relative abundance increased by a factor of 6 and 11, respectively, compared to the other digesters. The results further provide compelling evidence on the resilience of Fusobacteria, Actinobacteria and the Trojan horse-like effect of ENPs which offered a competitive advantage to some organisms while reducing microbial abundance and diversity.
Open Access
Air quality and mental health: evidence, challenges and future directions
(Cambridge University Press (CUP), 2023-07-05) Bhui, Kamaldeep; Newbury, Joanne B.; Latham, Rachel M.; Ucci, Marcella; Nasir, Zaheer A.; Turner, Briony; O'Leary, Catherine; Fisher, Helen L.; Marczylo, Emma; Douglas, Philippa; Stansfeld, Stephen; Jackson, Simon K.; Tyrrel, Sean; Rzhetsky, Andrey; Kinnersley, Rob; Kumar, Prashant; Duchaine, Caroline; Coulon, Frederic
Background: Poor air quality is associated with poor health. Little attention is given to the complex array of environmental exposures and air pollutants that affect mental health during the life course. Aims: We gather interdisciplinary expertise and knowledge across the air pollution and mental health fields. We seek to propose future research priorities and how to address them. Method: Through a rapid narrative review, we summarise the key scientific findings, knowledge gaps and methodological challenges. Results: There is emerging evidence of associations between poor air quality, both indoors and outdoors, and poor mental health more generally, as well as specific mental disorders. Furthermore, pre-existing long-term conditions appear to deteriorate, requiring more healthcare. Evidence of critical periods for exposure among children and adolescents highlights the need for more longitudinal data as the basis of early preventive actions and policies. Particulate matter, including bioaerosols, are implicated, but form part of a complex exposome influenced by geography, deprivation, socioeconomic conditions and biological and individual vulnerabilities. Critical knowledge gaps need to be addressed to design interventions for mitigation and prevention, reflecting ever-changing sources of air pollution. The evidence base can inform and motivate multi-sector and interdisciplinary efforts of researchers, practitioners, policy makers, industry, community groups and campaigners to take informed action. Conclusions: There are knowledge gaps and a need for more research, for example, around bioaerosols exposure, indoor and outdoor pollution, urban design and impact on mental health over the life course.
Open Access
Air quality and mental illness: role of bioaerosols, causal mechanisms and research priorities
(Royal College of Psychiatrists, 2024-09-19) Bhui, Kamaldeep; Ucci, Marcella; Kumar, Prashant; Jackson, Simon K; Whitby, Corinne; Colbeck, Ian; Pfrang, Christian; Nasir, Zaheer A; Coulon, Frederic
Background: Poor air quality can both trigger and aggravate lung and heart conditions, as well as affecting child development. It can even lead to neurological and mental health problems. However, the precise mechanisms by which air pollution affect human health are not well understood. Aims: To promote interdisciplinary dialogue and better research based on a critical summary of evidence on air quality and health, with an emphasis on mental health, and to do so with a special focus on bioaerosols as a common but neglected air constituent. Method: A rapid narrative review and interdisciplinary expert consultation, as is recommended for a complex and rapidly changing field of research. Results: The research methods used to assess exposures and outcomes vary across different fields of study, resulting in a disconnect in bioaerosol and health research. We make recommendations to enhance the evidence base by standardising measures of exposure to both particulate matter in general and bioaerosols specifically. We present methods for assessing mental health and ideal designs. There is less research on bioaerosols, and we provide specific ways of measuring exposure to these. We suggest research designs for investigating causal mechanisms as important intermediate steps before undertaking larger-scale and definitive studies. Conclusions: We propose methods for exposure and outcome measurement, as well as optimal research designs to inform the development of standards for undertaking and reporting research and for future policy.
Open Access
Almost 25 years of chromatographic and spectroscopic analytical method development for petroleum hydrocarbons analysis in soil and sediment: State-of-the-art, progress and trends
(Taylor & Francis, 2017-10-11) Douglas, Reward; Nawar, S.; Alamar, M. Carmen; Coulon, Frederic; Mouazen, Abdul M.
This review provides a critical insight into the selection of chromatographic and spectroscopic techniques for semi-quantitative and quantitative detection of petroleum hydrocarbons in soil and sediment matrices. Advantages and limitations of both field screening and laboratory-based techniques are discussed and recent advances in chemometrics to extract maximum information from a sample by using the optimal pre-processing and data mining techniques are presented. An integrated analytical framework based on spectroscopic techniques integration and data fusion for the rapid measurement and detection of on-site petroleum hydrocarbons is proposed. Furthermore, factors influencing petroleum hydrocarbons analysis in contaminated samples are discussed and recommendations on how to reduce their influence provided.
Open Access
Analysing oily wastes in soils
(Institution of Chemical Engineers, 2009-12-31T00:00:00Z) Coulon, Frederic
Many hydrocarbon contaminated sites posing potential risks to human health harbour weathered, ‘mid-distillate' or heavy oils. Now, a bioremediation consortium (PROMISE), led by Cranfield University, has developed a novel and robust analytical procedure for weathered hydrocarbon contaminated soils within a UK risk-based framewo
Open Access
Analysis of petroleum-contaminated soils by diffuse reflectance spectroscopy and sequential ultrasonic solvent extraction-gas chromatography
(Elsevier Science B.V., Amsterdam., 2014-01-31T00:00:00Z) Okparanma, R. N.; Coulon, Frederic; Mouazen, Abdul Mounem
In this study, we demonstrate that partial least-squares regression analysis with full cross-validation of spectral reflectance data estimates the amount of polycyclic aromatic hydrocarbons in petroleumcontaminated tropical rainforest soils. We applied the approach to 137 field-moist intact soil samples collected from three oil spill sites in Ogoniland in the Niger Delta province (5.317N, 6.467E), Nigeria. We used sequential ultrasonic solvent extractionegas chromatography as the reference chemical method. We took soil diffuse reflectance spectra with a mobile fibre-optic visible and near-infrared spectrophotometer (350e2500 nm). Independent validation of combined data from studied sites showed reasonable prediction precision (root-mean-square error of prediction ¼ 1.16e1.95 mg kg1, ratio of prediction deviation ¼ 1.86e3.12, and validation r2 ¼ 0.77e0.89). This suggests that the methodology may be useful for rapid assessment of the spatial variability of polycyclic aromatic hydrocarbons in petroleum-contaminated soils in the Niger Delta to inform risk assessment and remediation.
Open Access
Analytical progress and challenges for the detection of oxygenated polycyclic aromatic hydrocarbon transformation products in aqueous and soil environmental matrices: A review
(Taylor and Francis, 2019-01-11) Pulleyblank, Coren; Cipullo, Sabrina; Campo, Pablo; Kelleher, Brian; Coulon, Frederic
Over the past 20 years, a growing body of research has raised concerns about the toxicity, fate, and transport of oxygenated transformation products of polycyclic aromatic hydrocarbons. Research targeting these diverse compounds in soil and water systems has been challenged by a lack of standard analytical techniques and suitable reference materials. However, recent efforts towards the consolidation of traditional analytical techniques as well as the development of novel approaches to improve sample preparation and hyphenated instrumental techniques show promise. This review discusses progress and challenges for both trends in analytical method development and makes recommendations for supporting oxygenated PAH research.
Open Access
Applicability of factory calibrated optical particle counters for high-density air quality monitoring networks in Ghana
(Elsevier, 2020-06-16) Gameli Hodoli, Collins; Coulon, Frederic; Mead, Mohammed Iqbal
In this study, we demonstrate the feasibility of using miniaturised optical particle counters (OPCs) for understanding AQ in Sub-Saharan Africa. Specifically, the potential use of OPCs for high-density ground-based air pollution networks and the use of derived data for quantification of atmospheric emissions were investigated. Correlation and trend analysis for particulate matters (PM), including PM10, PM2.5 and PM1 were undertaken on hourly basis alongside modelled meteorological parameters. Hourly averaged PM values were 500 μg/m3, 90 μg/m3 and 60 μg/m3 for PM10, PM2.5 and PM1, respectively and Pearson's correlation coefficient ranged between 0.97 and 0.98. These levels are in the agreement with range of PM emission reported for these types of environmental settings. PM was locally associated with low wind speeds (<= 2 ms−1) and was closely linked to anthropogenic activities. This study provides a benchmark for future AQ and demonstrates the feasibility of the current generation of OPCs for AQ monitoring in environments typical of large parts of West and Sub Saharan Africa.
Open Access
The applicability of spectroscopy methods for estimating potentially toxic elements in soils: state-of-the art and future trends
(Taylor and Francis, 2019-05-08) Nawar, S.; Cipullo, Sabrina; Douglas, Reward; Coulon, Frederic; Mouazen, A. M.
Potentially toxic elements (PTEs) in soils pose severe threats to the environment and human health. It is therefore imperative to have access to simple, rapid, portable, and accurate methods for their detection in soils. In this regard, the review introduces recent progresses made in the development and applications of spectroscopic methods for in situ semi-quantitative and quantitative detection of PTEs in soil and critically compares them to standard analytical methods. The advantages and limitations of these methods are discussed together with recent advances in chemometrics and data mining techniques allowing to extract useful information based on spectral data. Furthermore, the factors influencing soil spectra and data analysis are discussed and recommendations on how to reduce or eliminate their influences are provided. Future research and development needs for spectroscopy techniques are emphasized, and an analytical framework based on technology integration and data fusion is proposed to improve the measurement accuracy of PTEs in soil.
Open Access
The application of a handheld mid-infrared spectrometry for rapid measurement of oil contamination in agricultural sites
(Elsevier, 2019-02-07) Douglas, R. K.; Nawar, S.; Alamar, M. Carmen; Coulon, Frederic; Mouazen, A. M.
Rapid analysis of oil-contaminated soils is important to facilitate risk assessment and remediation decision-making process. This study reports on the potential of a handheld mid-infrared (MIR) spectrometer for the prediction of total petroleum hydrocarbons (TPH), including aliphatic (alkanes) and polycyclic aromatic hydrocarbons (PAH) in limited number of fresh soil samples. Partial least squares regression (PLSR) and random forest (RF) modelling techniques were compared for the prediction of alkanes, PAH, and TPH concentrations in soil samples (n = 85) collected from three contaminated sites located in the Niger Delta, Southern Nigeria. Results revealed that prediction of RF models outperformed the PLSR with coefficient of determination (R2) values of 0.80, 0.79 and 0.72, residual prediction deviation (RPD) values of 2.35, 1.96, and 2.72, and root mean square error of prediction (RMSEP) values of 63.80, 83.0 and 65.88 mg kg−1 for TPH, alkanes, and PAH, respectively. Considering the limited dataset used in the independent validation (18 samples), accurate predictions were achieved with RF for PAH and TPH, while the prediction for alkanes was less accurate. Therefore, results suggest that RF calibration models can be used successfully to predict TPH and PAH using handheld MIR spectrophotometer under field measurement conditions.
Open Access
Are alkane hydroxylase genes (alkB) relevant to assess petroleum bioremediation processes in chronically polluted coastal sediments?
(Springer Science Business Media, 2011-11-30T00:00:00Z) Païssé, Sandrine; Duran, Robert; Coulon, Frederic; Goni-Urriza, Marisol
The diversity of alkB-related alkane hydroxylase sequences and the relationship between alkB gene expres- sion and the hydrocarbon contamination level have been investigated in the chronically polluted Etang-de-Berre sediments. For this purpose, these sediments were main- tained in microcosms and submitted to a controlled oil input miming an oil spill. New degenerated PCR primers targeting alkB-related alkane hydroxylase sequences were designed to explore the diversity and the expression of these genes using terminal restriction fragment length polymorphism fingerprinting and gene library analyses. Induction of alkB genes was detected immediately after oil addition and their expression detected only during 2 days, although the n-alkane degradation was observed throughout the 14 days of incubation. The alkB gene expression within triplicate microcosms was heterogeneous probably due to the low level of alkB transcripts. Moreover, the alkB gene expression of dominant OTUs has been observed in unoiled microcosms indicating that the expression of this gene cannot be directly related to the oil contamination. Although the dominant alkB genes and transcripts detected were closely related to the alkB of Marinobacter aquaeolei isolated from an oil- producing well, and to alkB genes related to the obligate alkanotroph Alcanivorax borkumen- sis, no clear relationship between the oil contamination and the expression of the alkB genes could be established. This finding suggests that in such coastal environments, alkB gene expression is not a function relevant enough to monitor bacterial response to oil contamination.
Open Access
Assessing bioavailability of complex mixtures in contaminated soils: progress made and research needs
(Elsevier, 2017-10-17) Cipullo, Sabrina; Prpich, George; Campo, Pablo; Coulon, Frederic
Understanding the distribution, behaviour and interactions of complex chemical mixtures is key for providing the evidence necessary to make informed decisions and implement robust remediation strategies. Much of the current risk assessment frameworks applied to manage land contamination are based on total contaminant concentrations and the exposure assessments embedded within them do not explicitly address the partitioning and bioavailability of chemical mixtures. These oversights may contribute to an overestimation of both the eco-toxicological effects of the fractions and the mobility of contaminants. In turn, this may limit the efficacy of risk frameworks to inform targeted and proportionate remediation strategies. In this review we analyse the science surrounding bioavailability, its regulatory inclusion and the challenges of incorporating bioavailability in decision making process. While a number of physical and chemical techniques have proven to be valuable tools for estimating bioavailability of organic and inorganic contaminants in soils, doubts have been cast on its implementation into risk management soil frameworks mainly due to a general disagreement on the interchangeable use of bioavailability and bioaccessibility, and the associated methods which are still not standardised. This review focuses on the role of biotic and abiotic factors affecting bioavailability along with soil physicochemical properties and contaminant composition. We also included advantages and disadvantages of different extraction techniques and their implications for bioavailability quantitative estimation. In order to move forward the integration of bioavailability into site-specific risk assessments we should (1) account for soil and contaminant physicochemical characteristics and their effect on bioavailability; (2) evaluate receptor's potential exposure and uptake based on mild-extraction; (3) adopt a combined approach where chemical-techniques are used along with biological methods; (4) consider a simplified and cost-effective methodology to apply at regulatory and industry setting; (5) use single-contaminant exposure assessments to inform and predict complex chemical mixture behaviour and bioavailability.
Open Access
Assessing metal extraction from metalliferous waste: A study using deep eutectic solvents and chelating agents vs. ethylenediaminetetraacetic acid
(Elsevier, 2024-06-07) Huntington, Victoria E.; Coulon, Frederic; Wagland, Stuart T.
Conventional methods of metal recovery involving solvents have raised environmental concerns. To address these concerns and promote sustainable resource recovery, we explored the use of deep eutectic solvents (DES) and chelating agents (CA) as more environmentally friendly alternatives. Goethite and blast oxide slag dust (BOS-D) from heap piles at their respective sites and characterised via ICP-MS. The greatest extraction of critical metals was from goethite, removing 38% of all metals compared to 21% from the blast oxide slag. Among the tested CA, nitrilotriacetic acid (NTA) was the most effective, while for DES, choline chloride ethylene glycol (ChCl-EG) demonstrated superior performance in extracting metals from both blast oxide slag dust and goethite. The study further highlighted the selectivity for transition metals and metalloids was influenced by the carboxyl groups of DES. Alkaline metals and rare earth lanthanides extractions were favoured with DES due to improved mass transfer and increased denticity, respectively. In comparison to ethylenediaminetetraacetic acid (EDTA), typically used for metal extraction, CA and DES showed comparable extraction efficiency for Fe, Cu, Pb, Li, Al, Mn, and Ni. Using these greener chelators and solvents for metal extraction show significant promise in enhancing the sustainability of solvometallurgy. Additional conditions e.g., temperature and agitation combined with a cascading leaching process could further enhance metal extraction potential.
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, Stuart
Recovery 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.
Open Access
Assessing resource recovery potentials of industrial metal-bearing by-products using bioleaching.
(Cranfield University, 2023-12) Tezyapar Kara, Ipek; Coulon, Frederic; Wagland, Stuart
The global transition to a circular economy calls for research and development on technologies facilitating sustainable resource recovery from wastes and by- products as some possessing comparable or superior quality to natural ores. Traditional methods e.g., pyrometallurgy and hydrometallurgy are considered as inefficient for processing secondary resources as they often cause harmful emissions and loss of metals, require high capital cost. Bioleaching, which emerges as an eco-friendly and cost-effective alternative to conventional methods, is well established for metal extraction from low-grade sulfidic ores, tailings, and metallurgical side streams, yet the method is at the research stage for other secondary resources such as metallurgical slag and dust, fly ash, e- waste. The aim of this PhD study was assessing the resource recovery potentials of industrial metal-bearing by-products using biomining. Firstly, this study critically reviewed the microbial diversity and specific mechanisms of bioleaching as well as the current operations and approaches of bioleaching at various scales and summarised the influence of a broad range of operational parameters. Then, suggested an optimisation route for bioleaching of metal-bearing materials for laboratory scale bioleaching operations to further inform pilot/commercial scale operations. Further to this, feasibility of extracting metals from two industrial metal-bearing by-products which were basic oxygen steelmaking dust (BOS-D) and goethite were investigated using Acidithiobacillus ferrooxidans. Taguchi orthogonal array design was used to evaluate the effect of four parameters which were pulp density, energy source concentration, inoculum concentration, and pH at three different levels. Then methods were explored for enhancing and scaling up the extraction of metals from BOS-D. Finally, techno-economic assessment conducted for two potential industrial scale bioleaching technologies including an aerated bioreactor and an aerated and stirred bioreactor, for different metal recovery scenarios from the industrial metal-bearing by-products.
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, E.; Hirvonen, S.; Valjus, Tuire; Lerssi, J.; Dino, G. A.; Piergiorgio, R.; Griffiths, Zoe; Wagland, Stuart; Coulon, Frederic
Many 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.