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15 pages, 11293 KiB

Open AccessArticle

An Assessment of the Stereo and Near-Infrared Camera Calibration Technique Using a Novel Real-Time Approach in the Context of Resource Efficiency

by Larisa Ivascu, Vlad-Florin Vinatu and Mihail Gaianu

Processes 2025, 13(4), 1198; https://doi.org/10.3390/pr13041198 - 15 Apr 2025

Viewed by 223

Abstract

This paper provides a comparative analysis of calibration techniques applicable to stereo and near-infrared (NIR) camera systems, with a specific emphasis on the Intel RealSense SR300 alongside a standard 2-megapixel NIR camera. This study investigates the pivotal function of calibration within both stereo [...] Read more.

This paper provides a comparative analysis of calibration techniques applicable to stereo and near-infrared (NIR) camera systems, with a specific emphasis on the Intel RealSense SR300 alongside a standard 2-megapixel NIR camera. This study investigates the pivotal function of calibration within both stereo vision and NIR imaging applications, which are essential across various domains, including robotics, augmented reality, and low-light imaging. For stereo systems, we scrutinise the conventional method involving a 9 × 6 chessboard pattern utilised to ascertain the intrinsic and extrinsic camera parameters. The proposed methodology consists of three main steps: (1) real-time calibration error classification for stereo cameras, (2) NIR-specific calibration techniques, and (3) a comprehensive evaluation framework. This research introduces a novel real-time evaluation methodology that classifies calibration errors predicated on the pixel offsets between corresponding points in the left and right images. Conversely, NIR camera calibration techniques are modified to address the distinctive properties of near-infrared light. We deliberate on the difficulties encountered in devising NIR–visible calibration patterns and the imperative to consider the spectral response and temperature sensitivity within the calibration procedure. The paper also puts forth an innovative calibration assessment application that is relevant to both systems. Stereo cameras evaluate the corner detection accuracy in real time across multiple image pairs, whereas NIR cameras concentrate on assessing the distortion correction and intrinsic parameter accuracy under varying lighting conditions. Our experiments validate the necessity of routine calibration assessment, as environmental factors may compromise the calibration quality over time. We conclude by underscoring the disparities in the calibration requirements between stereo and NIR systems, thereby emphasising the need for specialised approaches tailored to each domain to guarantee an optimal performance in their respective applications. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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11 pages, 1124 KiB

Open AccessArticle

Production of Sustainable Yarn Incorporating Process Waste to Promote Sustainability

by Ahmed Hamzi, Ahsan Habib, Osman Babaarslan, Mastoor M. Abushaega, Md Masum and Md. Abdullah al Mamun

Processes 2025, 13(3), 764; https://doi.org/10.3390/pr13030764 - 6 Mar 2025

Cited by 1 | Viewed by 667

Abstract

The spinning industry makes a major contribution to environmental pollution due to the excessive use of natural assets and the generation of remarkable amounts of waste during manufacturing processes. Now, the spinning industries are concentrating on sustainable activities due to environmental issues. While [...] Read more.

The spinning industry makes a major contribution to environmental pollution due to the excessive use of natural assets and the generation of remarkable amounts of waste during manufacturing processes. Now, the spinning industries are concentrating on sustainable activities due to environmental issues. While textile recycling efforts have been widely explored, the utilization of soft waste (process waste) in yarn production remains underexplored. This study addresses this gap by investigating a sustainable approach incorporating soft waste into producing sustainable yarn using the ring-spinning technique. The research explores the properties of yarns manufactured from a blend of virgin cotton and soft waste, and 100% virgin cotton yarn is produced for comparison. The results indicate that incorporating soft waste leads to an increase in CVm% (13 vs. 11), hairiness (6.9 vs. 5.1), and IPI (165 vs. 125) compared to virgin cotton yarn. However, the elongation percentage (7.1% vs. 8%) and tensile strength (12.6 cN/tex vs. 16.2 cN/tex) showed a reduction, highlighting potential trade-offs in mechanical properties. The statistical analysis applies one-way ANOVA to evaluate the significance of variations in yarn characteristics made from the mixture of soft waste + virgin cotton and only virgin cotton. The manufactured yarns were examined in a modern weaving machine as weft yarn for fabric (denim) manufacturing and found to be perfect for normal operation. The article focuses on reducing negative impacts on the fabric (denim) manufacturing environment by incorporating soft waste to produce sustainable yarn. This research provides important insights into the production of sustainable yarns, focusing on environmental concerns. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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18 pages, 4829 KiB

Open AccessArticle

Purification of CaF₂ from Fluorine-Containing Sludge: Optimization via Calcium Ion Coexistence Effect

by Danyang Zhu, Xiang Chen, Hui Gong, Xiankai Wang, Xueyuan Qiao and Xiaohu Dai

Processes 2025, 13(2), 552; https://doi.org/10.3390/pr13020552 - 16 Feb 2025

Viewed by 645

Abstract

The rapid development of the photovoltaic industry has significantly increased fluorine-containing sludge production. Calcium fluoride (CaF₂), a vital non-renewable raw material used in optics, metallurgy, and chemical synthesis, holds immense significance for ensuring the sustainable supply of fluoride resources. This study [...] Read more.

The rapid development of the photovoltaic industry has significantly increased fluorine-containing sludge production. Calcium fluoride (CaF₂), a vital non-renewable raw material used in optics, metallurgy, and chemical synthesis, holds immense significance for ensuring the sustainable supply of fluoride resources. This study focuses on purifying CaF₂ from fluorine-containing sludge using a systematic approach. Through characterization techniques such as XRF, SEM-EDS, XRD, FT-IR, and laser granulometry, the sludge’s composition was thoroughly analyzed. An acid-leaching–alkali-leaching method was proposed and validated for CaF₂ purification. A key finding during acid leaching was the “calcium ion coexistence effect”, where the dissolution of other calcium salts influences CaF₂ dissolution equilibrium, reducing its loss. Leveraging this phenomenon, an optimized strategy was developed by increasing acid concentration while reducing acid volume. This approach effectively addresses two common challenges in traditional acid-leaching processes: high CaF₂ dissolution loss and difficulties in impurity removal. Experimental results revealed that under optimized acid-leaching conditions, the purity of CaF₂ increased significantly from an initial 36.7 wt% to 76.1 wt% after acid-leaching–alkali-leaching. This study demonstrates a successful method for purifying CaF₂ from fluorine-containing sludge, providing a sustainable solution for fluoride resource recovery. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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16 pages, 805 KiB

Open AccessArticle

Production and Physicochemical and Microbiological Evaluation of Orange-Flesh Sweet Potato Flatbread Infused with Spinach as a Healthy Food Option

by Colleen Castillo, Vidya de Gannes, Gaius Eudoxie, Wendy-Ann P. Isaac and Sivakumar Karuppusamy

Processes 2025, 13(2), 427; https://doi.org/10.3390/pr13020427 - 5 Feb 2025

Viewed by 669

Abstract

Consumers’ preferences for healthier food products are increasing worldwide. Flatbread, a highly versatile product traditionally formulated with wheat flour (WF), offers significant potential for innovation and value addition through biofortification. Biofortification of flatbread was assessed with orange-flesh sweet potato (Ipomoea batatas L.) [...] Read more.

Consumers’ preferences for healthier food products are increasing worldwide. Flatbread, a highly versatile product traditionally formulated with wheat flour (WF), offers significant potential for innovation and value addition through biofortification. Biofortification of flatbread was assessed with orange-flesh sweet potato (Ipomoea batatas L.) flour (OFSP) infused with spinach (Amaranthus dubius). The purpose of this experiment was to ascertain the impact of adding local OFSP flour and spinach on the physicochemical, sensory, and microbial aspects of sweet potato-spinach infused WF flatbread. Six different flatbread formulations were created using OFSP flour, WF, and spinach. The study utilized a randomised 3 × 2 factorial design, with each treatment reproduced four times, totalling 24 treatments. Sensory evaluation for OFSP flour-spinach flatbreads received appreciable scores. OFSP flour flatbreads exhibited acceptable levels of protein, ash, fat, and moisture. The study provided formulations for value-added flatbread with the efficient inclusion of local agricultural resources OFSP and spinach to produce healthier food product offerings that were microbiologically safe. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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21 pages, 2682 KiB

Open AccessArticle

Environmental Assessment and Eco-Efficiency Analysis of the Dividing Wall Distillation Column for Separating a Benzene–Toluene–Xylene Mixture

by Fernanda Ribeiro Figueiredo and Diego Martinez Prata

Processes 2025, 13(2), 391; https://doi.org/10.3390/pr13020391 - 1 Feb 2025

Viewed by 772

Abstract

The benzene–toluene–xylene (BTX) system represents an energy-intensive petrochemical process with various industrial applications. Global climate changes have forced modern industry to act toward environmental safety, which requires technological changes. Thus, the divided wall column (DWC) represents a significant advancement in multicomponent mixture separation. [...] Read more.

The benzene–toluene–xylene (BTX) system represents an energy-intensive petrochemical process with various industrial applications. Global climate changes have forced modern industry to act toward environmental safety, which requires technological changes. Thus, the divided wall column (DWC) represents a significant advancement in multicomponent mixture separation. To assess the impact of the conventional BTX process and its intensification proposal based on DWC technology, it is necessary to integrate an eco-efficiency approach that jointly analyzes the economic and environmental variables influencing the system, such as water consumption, CO₂ emissions, and utility costs. An auxiliary utility plant was also considered for more realistic results in terms of energy and water consumption, which was identified as a lack in many research studies that performed an overall sustainability analysis. The results showed that the DWC scheme is 37.5% more eco-efficient than the conventional counterpart, mainly due to a 15.6% and 30.3% savings on energy and water consumption, respectively, which provided a 15.5% and 16.7% reduction on CO₂ emissions and utility costs, respectively. In addition, all other environmental and safety indicators based on the waste algorithm reduction (WAR) were reduced by approximately 16%. Thus, the DWC proved to be a convenient technology with economic attractiveness and environmental friendliness. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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17 pages, 618 KiB

Open AccessArticle

Enhancing Pereskia aculeata Mill. Cultivation with LED Technology: A Sustainable Approach

by Nayara Vieira Silva, Ailton Cesar Lemes, Fabiano Guimarães Silva, Bruno Matheus Mendes Dário, Jenifer Ribeiro de Jesus, Tainara Leal de Sousa, Sibele Santos Fernandes and Mariana Buranelo Egea

Processes 2024, 12(12), 2695; https://doi.org/10.3390/pr12122695 - 29 Nov 2024

Viewed by 836

Abstract

Using light-emitting diode (LED) in plant production optimizes growth with higher energy efficiency, reduces carbon footprint and resource consumption, and promotes more sustainable agriculture. However, the plants’ growth characteristics and biochemical composition may vary depending on the light’s wavelength, spectrum, and intensity. Therefore, [...] Read more.

Using light-emitting diode (LED) in plant production optimizes growth with higher energy efficiency, reduces carbon footprint and resource consumption, and promotes more sustainable agriculture. However, the plants’ growth characteristics and biochemical composition may vary depending on the light’s wavelength, spectrum, and intensity. Therefore, LEDs as a light source have become a promising choice for improving cultivation efficiency, as they can modulate the spectrum to meet the needs of plants. Pereskia aculeata is a plant species from the cactus family with high protein, vitamins, minerals, and fiber. The objective of this study was to evaluate the effect of LED lighting on the cultivation of P. aculeata and its influence on biometric color and physicochemical aspects. Two treatments were carried out without the addition of artificial light: one inside the greenhouse (C-ins) and the other outside the greenhouse (C-out), and four treatments with LEDs in different spectral bands: monochromatic red (600–700 nm) (Red), monochromatic blue (400–490 nm) (Blue), white (400–700 nm) (White), and blue–red (1:1) (Blue–Red). The biometric characteristics and the color of the leaves collected from the different treatments were evaluated. After this, the leaves were dried, ground, and evaluated. The physicochemical and thermal characteristics, bioactive compounds, and antioxidant activity of the leaves from each treatment were described. The biometric characteristics were intensified with red LED, and the color of the leaves tended toward green. The dried yield was around 50%, except for C-out treatment. Regarding nutritional characteristics, the highest protein (29.68 g/100 g), fiber (34.44 g/100 g), ash (20.28 g/100 g), and lipid (3.44 g/100 g) contents were obtained in the treatment with red light. The red treatment also intensified the content of chlorophyll a (28.27 µg/L) and total carotenoids (5.88 µg/g). The blue treatment intensified the concentration of minerals and provided greater thermal stability. Regarding bioactive properties, the cultivation of P. aculeata inside the greenhouse favored the concentration of phenolic compounds and a greater antioxidant capacity. Therefore, the quality of light for P. aculeata demonstrates that the length of red and blue light corroborates the development of the plant through the wavelength absorbed by the leaves, favoring its characteristics and planting in closed environments. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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16 pages, 6052 KiB

Open AccessArticle

Numerical Simulation of Hydraulic Fracture Propagation in Unconsolidated Sandstone Reservoirs

by Yicheng Xin, Zheng Yuan, Yancai Gao, Tao Wang, Haibiao Wang, Min Yan, Shun Zhang and Xian Shi

Processes 2024, 12(10), 2226; https://doi.org/10.3390/pr12102226 - 12 Oct 2024

Cited by 1 | Viewed by 1622

Abstract

In order to comprehensively understand the complex fracture mechanisms in thick and loose sandstone formations, we have carefully developed a coupled finite element numerical model that captures the complex interactions between fluid flow and solid deformation. This model is the cornerstone of our [...] Read more.

In order to comprehensively understand the complex fracture mechanisms in thick and loose sandstone formations, we have carefully developed a coupled finite element numerical model that captures the complex interactions between fluid flow and solid deformation. This model is the cornerstone of our future exploration. Based on this model, the crack propagation problem of hydraulic fracturing under different engineering and geological conditions was studied. In addition, we conducted in-depth research on the key factors that shape the geometry of hydraulic fractures, revealing their subtle differences and complexities. It is worth noting that the sharp contrast between the stress profile and mechanical properties between the production layer and the boundary layer often leads to fascinating phenomena, such as the vertical merging of hydraulic fracture propagation. The convergence of cracks originating from adjacent layers is a recurring theme in these strata. Sensitivity analysis clarified our understanding, revealing that increased elastic modulus promotes longer crack propagation paths. As the elastic modulus increases from 12 GPa to 18 GPa, overall, the maximum crack width slightly decreases, with a less than 10% reduction rate. The increased fluid leakage rate will significantly shorten the length and width of hydraulic fractures (with a maximum decrease of over 70% in fracture width). The increase in viscosity of fracturing fluid causes a change in fracture morphology, with a reduction in length of about 32% and an increase in fracture width of about 25%. It is worth noting that as the leakage rate of fracturing fluid increases, the importance of the viscosity of fracturing fluid decreases relatively. Strategies such as increasing fluid viscosity or adding anti-filtration agents can alleviate these challenges and improve the efficiency of fracturing fluids. In summary, our research findings provide valuable insights that can provide information and optimization for hydraulic fracturing filling and fracturing strategies in loose sandstone formations, promoting more efficient and influential oil and gas extraction work. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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23 pages, 2005 KiB

Open AccessArticle

The Paradox of Nuclear Power Plants (NPPs) between High-Efficiency Energy and Waste Management Concerns in the Context of Disasters Worldwide

by Laura Elly Naghi, Narcis Sebastian Păvălașcu and Manuela Rozalia Gabor

Processes 2023, 11(3), 953; https://doi.org/10.3390/pr11030953 - 20 Mar 2023

Cited by 3 | Viewed by 3818

Abstract

With the uncertainty concerning the future use of natural resources due to depletion and lack of access caused by the pandemic and recent political events that led to increased prices, nuclear energy may become an alternative efficient energy. NPPs raise serious concerns, including [...] Read more.

With the uncertainty concerning the future use of natural resources due to depletion and lack of access caused by the pandemic and recent political events that led to increased prices, nuclear energy may become an alternative efficient energy. NPPs raise serious concerns, including waste management, and any case of an NPP accident has the potential to disrupt the positive impact of energy production in terms of circular economies. Our research analyzed the impact of nuclear incidents as examples of disasters worldwide to decide whether any of the different forms of insurance coverage could be useful in future events. By using 2533 historical records of incidents from 1901 to June 2022, we set out to find the best predictor of damage causes and further observe whether the validation of current forms of insurance may be possible. The disaster subtype and declaration represent the best predictor of the total damage value (adjusted or not) for all types of disasters, including nuclear. The results are important inputs for underwriters working in insurance, including in radioactive waste management, which must consider historical data in order to tailor future contracts, adjusting the cost and coverage to the type of disaster. Our results highlight that with an increase of only one event involving a nuclear source, the total adjusted damages will increase by USD 1,821,087.09 thousand, representing 75% of the damage costs of the rest of the disaster subtypes. The results are useful for public entities to evaluate nuclear energy as a new solution and can help further adapt existing policies to include better responses for waste prevention, reuse and recycling. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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19 pages, 1530 KiB

Open AccessFeature PaperArticle

Organizational Agility and Sustainable Manufacturing Practices in the Context of Emerging Economy: A Mediated Moderation Model

by Jianmin Sun, Muddassar Sarfraz, Jamshid Ali Turi and Larisa Ivascu

Processes 2022, 10(12), 2567; https://doi.org/10.3390/pr10122567 - 2 Dec 2022

Cited by 9 | Viewed by 3963

Abstract

Since the beginning of the 21st century, agility and sustainability have played a significant role in the global manufacturing industry. The manufacturing paradigm leaning toward green procurement and organizational agility has crossed all levels of sustainability by colossally influencing the firms’ sustainable practices, [...] Read more.

Since the beginning of the 21st century, agility and sustainability have played a significant role in the global manufacturing industry. The manufacturing paradigm leaning toward green procurement and organizational agility has crossed all levels of sustainability by colossally influencing the firms’ sustainable practices, innovation capacity, and eco-friendly procurements. Integrating sustainable practices in manufacturing is a complex task that demands that global economies conduct comprehensive research on the factors influencing the firms’ sustainable practices. Therefore, the study considers empirical research between organizational agility and sustainable manufacturing practices. The data was collected from 461 respondents working in the manufacturing sector by applying a convenience sampling technique. We utilized structural equation modeling (SEM) for direct and indirect hypothesis testing. The study results revealed that operational, customer, and partnering agility significantly and positively impact sustainable manufacturing practices and green procurement. Green procurement mediates the relationship between operational, customer, partnering agility and sustainable manufacturing practices. The study results showed a significant moderating role of big data between green procurement and sustainable manufacturing practices. The study findings are helpful to managers and policymakers. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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Review

Jump to: Research

28 pages, 2694 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Critical Review of Lithium Recovery Methods: Advancements, Challenges, and Future Directions

by Subin Antony Jose, Jonathan Luke Stoll, Tyson Smith, Chase Jackson, Trent Dieleman, Easton Leath, Nicholas Eastwood and Pradeep L. Menezes

Processes 2024, 12(10), 2203; https://doi.org/10.3390/pr12102203 - 10 Oct 2024

Cited by 11 | Viewed by 6723

Abstract

The integration of lithium into technological applications has profoundly influenced human development, particularly in energy storage systems like lithium-ion batteries. With global demand for lithium surging alongside technological advancements, the sustainable extraction and recovery of this critical material have become increasingly vital. This [...] Read more.

The integration of lithium into technological applications has profoundly influenced human development, particularly in energy storage systems like lithium-ion batteries. With global demand for lithium surging alongside technological advancements, the sustainable extraction and recovery of this critical material have become increasingly vital. This paper explores lithium’s role, its chemical properties, and the environmental and economic considerations associated with its extraction and recovery. We examine various lithium recovery methods, including conventional techniques such as hydrometallurgy, pyrometallurgy, and direct physical recycling, as well as emerging technologies like mechanochemistry, ion pumping, and bioleaching while emphasizing the need for sustainable practices to address environmental challenges. The review also discusses the challenges and future directions of lithium recovery. Advances in technology have streamlined lithium recovery processes and spurred the development of innovative extraction techniques. This paper concludes with an emphasis on further research essential to deepen our understanding of lithium recovery methods, their strengths and limitations, and the need to explore new strategies to meet the growing global demand for this indispensable resource. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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13 pages, 1741 KiB

Open AccessReview

The Transformation Path of Industrial Parks under the Goals of Carbon Peak and Neutrality in China

by Meirong Li, Huiyuan Liu, Yongyang Sun, Zhanxing Xu, Haoyong Tian and Haoyang Fu

Processes 2024, 12(10), 2197; https://doi.org/10.3390/pr12102197 - 10 Oct 2024

Viewed by 2959

Abstract

China’s coal-based energy structure and its large proportion of the manufacturing industry have resulted in China having the highest CO₂ emissions in the world, accounting for about one-third of the world’s total emissions. Achieving the carbon peak by 2030 and carbon neutrality [...] Read more.

China’s coal-based energy structure and its large proportion of the manufacturing industry have resulted in China having the highest CO₂ emissions in the world, accounting for about one-third of the world’s total emissions. Achieving the carbon peak by 2030 and carbon neutrality by 2060, while maintaining economic development, presents a significant challenge. Industrial parks, as core units of industrial clusters, are major sites for energy consumption and CO₂ emissions. Thus, industry parks with great carbon reduction potential are crucial for China’s carbon reduction efforts. This review systematically examines the current state of the carbon emissions of industrial parks in China and analyzes the situation and challenges faced in the low-carbon transition of these parks. Then, the major pathways, technologies, and key policies for the low-carbon transition are summarized based on the current situation. This paper assists in the low-carbon development of industrial parks and promotes the proposal and implementation of carbon emission reduction strategies. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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24 pages, 11491 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Towards Sustainable Lithium-Ion Battery Recycling: Advancements in Circular Hydrometallurgy

by Maria del Mar Cerrillo-Gonzalez, Maria Villen-Guzman, Carlos Vereda-Alonso, Jose Miguel Rodriguez-Maroto and Juan Manuel Paz-Garcia

Processes 2024, 12(7), 1485; https://doi.org/10.3390/pr12071485 - 15 Jul 2024

Cited by 15 | Viewed by 5971

Abstract

The growing demand for lithium-ion batteries (LIBs) has led to significant environmental and resource challenges, such as the toxicity of LIBs’ waste, which pose severe environmental and health risks, and the criticality of some of their components. Efficient recycling processes are essential to [...] Read more.

The growing demand for lithium-ion batteries (LIBs) has led to significant environmental and resource challenges, such as the toxicity of LIBs’ waste, which pose severe environmental and health risks, and the criticality of some of their components. Efficient recycling processes are essential to mitigate these issues, promoting the recovery of valuable materials and reducing environmental pollution. This review explores the application of electrodialysis in the process of recycling LIBs to contribute to the principles of circular hydrometallurgy. The article is structured to provide a comprehensive understanding of the topic, starting with an overview of the environmental and resource challenges associated with manufacturing LIBs. Then the current recycling processes are presented, focusing on hydrometallurgical methods. The concept of circular hydrometallurgy is introduced, emphasizing sustainable resource recovery. The electrodialysis technique is described in this context, highlighting its integration into the process of recycling LIBs to separate and recover valuable metals. Finally, the article addresses the challenges and limitations of the electrodialysis technique, such as energy consumption and system optimization, and identifies areas for future research and development. Through this analysis, the review aimed to contribute to advancing the development of more sustainable and efficient LIB recycling technologies, ensuring a safer and more environmentally friendly approach to the management of batteries’ lifecycle. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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39 pages, 8528 KiB

Open AccessReview

Review of Methods for Obtaining Rare Earth Elements from Recycling and Their Impact on the Environment and Human Health

by Despina A. Gkika, Michail Chalaris and George Z. Kyzas

Processes 2024, 12(6), 1235; https://doi.org/10.3390/pr12061235 - 16 Jun 2024

Cited by 14 | Viewed by 7336

Abstract

Rare earth elements (REEs) are at the forefront of discussions, given their crucial role in cutting-edge and eco-friendly innovations that propel the industrial revolution towards a green economy. These elements have become indispensable to various modern technologies, such as smartphones, electronic devices, and [...] Read more.

Rare earth elements (REEs) are at the forefront of discussions, given their crucial role in cutting-edge and eco-friendly innovations that propel the industrial revolution towards a green economy. These elements have become indispensable to various modern technologies, such as smartphones, electronic devices, and renewable energy sources. Many different concepts and analyses have been introduced, such as the chemical similarities among REEs, health risks and ecological damages, the negative environmental impacts of current recovery processes, and strategies for advancing REE recovery towards a circular economy. Although these elements have been widely used in various applications over the last 20 years, the literature on these aspects is fragmented and spread across different research areas, shared by multiple branches and application fields. These fields include safety concerns, economic challenges, and technology. Summarizing and classifying this literature is challenging due to its fragmented nature, the variety of topics, and the different approaches used. The quest for cleaner recycling strategies necessitates a comprehensive assessment covering economic, technological, and environmental aspects. The primary goal of this review is to provide a holistic perspective on REEs, with a central focus on their economic, technological, and environmental dimensions, particularly emphasizing reuse, recycling, and occupational safety. The review begins by addressing complexities of REEs, highlighting the associated technologies, environmental concerns, and economic considerations. It further explores the aspects of reuse and recycling of REEs, shedding light on the advantages, drawbacks, hazards, and costs associated with recycling technologies for REE recovery. Additionally, the review summarizes occupational exposure and safety considerations related to REEs. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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18 pages, 2902 KiB

Open AccessFeature PaperReview

Exopolysaccharides of Fungal Origin: Properties and Pharmaceutical Applications

by Roxana Mădălina Stoica, Misu Moscovici, Elena Simina Lakatos and Lucian Ionel Cioca

Processes 2023, 11(2), 335; https://doi.org/10.3390/pr11020335 - 20 Jan 2023

Cited by 12 | Viewed by 4751

Abstract

Fungal exopolysaccharides (EPSs) represent an important group of bioactive compounds secreted by fungi. These biopolymers can be utilized individually or in combination with different bioactive substances for a broad range of pharmaceutical field applications, due to their various biological activities, such as antioxidant, [...] Read more.

Fungal exopolysaccharides (EPSs) represent an important group of bioactive compounds secreted by fungi. These biopolymers can be utilized individually or in combination with different bioactive substances for a broad range of pharmaceutical field applications, due to their various biological activities, such as antioxidant, antimicrobial, anti-inflammatory, antiviral, anti-diabetic, and anticoagulant effects. The paper presents an up-to-date review of the main fungal polysaccharides (pullulan, schizophyllan, scleroglucan, botryosphaeran, lentinan, grifolan, and lasiodiplodan), highlighting their structures, producing strains, and useful properties in a double position, as controlled release (rate and selectively targeting) drug carriers, but mostly as active immunomodulating and antitumor compounds in cancer therapy. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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16 pages, 727 KiB

Open AccessReview

A Systematic Review on Biosurfactants Contribution to the Transition to a Circular Economy

by Elena Simina Lakatos, Lucian Ionel Cioca, Andrea Szilagyi, Mariana Gratiela Vladu, Roxana Mădălina Stoica and Misu Moscovici

Processes 2022, 10(12), 2647; https://doi.org/10.3390/pr10122647 - 8 Dec 2022

Cited by 7 | Viewed by 2918

Abstract

Since they are more environmentally acceptable than their chemically synthesized counterparts, biosurfactants are used in a wide range of environmental applications. However, less research has been done on biosurfactants within the context of the circular economy, despite their theoretical potential to fulfill a [...] Read more.

Since they are more environmentally acceptable than their chemically synthesized counterparts, biosurfactants are used in a wide range of environmental applications. However, less research has been done on biosurfactants within the context of the circular economy, despite their theoretical potential to fulfill a number of circular economy ambitions, including closing the consumption loop, regenerating natural systems, and maintaining resource value within the system. Hence, the main objective of this review is to identify and analyze the contributions of biosurfactants to the implementation of the circular economy. A final sample of 30 papers from the Web of Science database was examined. We identified five broad categories of contributions: waste stream-derived production, combating food waste, strengthening soil health, and improving the efficiency of water resources. We concluded that, while manufacturing biosurfactants from waste streams can reduce production costs, optimizing yield remains a contentious issue that complicates the adoption of biosurfactants into the circular economy framework. Full article

(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources (Volume II))

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