Resources

13 pages, 3885 KiB

Open AccessArticle

System Dynamics Modelling: Integrating Empty Fruit Bunch Biomass Logistics to Reduce GHG Emissions

by Iffat Abbas Abbasi, Hasbullah Ashari and Ijaz Yusuf

Resources 2023, 12(4), 53; https://doi.org/10.3390/resources12040053 - 18 Apr 2023

Cited by 1 | Viewed by 1385

The world is shifting toward renewable energy sources due to global warming and rising GHG emissions. Malaysia has joined other nations in the conference of parties to develop policies for the reduction of GHG and carbon emissions. Malaysia is switching towards sustainable, eco-friendly [...] Read more.

The world is shifting toward renewable energy sources due to global warming and rising GHG emissions. Malaysia has joined other nations in the conference of parties to develop policies for the reduction of GHG and carbon emissions. Malaysia is switching towards sustainable, eco-friendly and renewable energy sources. EFB biomass, one of the by-products of palm oil, has enormous potential as a sustainable energy source. Malaysia, one of the top exporters of palm oil, is unable to employ EFB-biomass-based power generation due to storage, logistics and supply-chain-related constraints. Therefore, this study integrates EFB biomass supply-chain logistics to overcome the reported challenges. The current study employs the system dynamics (SD) approach to achieve the objectives as it explains the dynamics of interaction and behaviour among the sub-systems. A document-based model-building approach is employed to collect data to develop the base model. The document-based model-building approach and system dynamics modelling facilitates the achievement of two outcomes: integrated EFB biomass logistics and GHG reduction using EFB. These outcomes are crucial to enhancing the base model and realizing the zero-carbon emission goal to contribute to sustainable development goals. Full article

(This article belongs to the Special Issue Women's Special Issue Series: Sustainable Resource Management)

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16 pages, 737 KiB

Open AccessArticle

Human Capital and Environmental Sustainability Nexus in Selected SADC Countries

by Kin Sibanda, Dorcas Gonese and Rufaro Garidzirai

Resources 2023, 12(4), 52; https://doi.org/10.3390/resources12040052 - 18 Apr 2023

Cited by 2 | Viewed by 1620

Abstract

This paper sought to examine the nexus between human capital and environmental sustainability in Southern African Development Community (SADC) countries. This contemporary topic has not received much attention in the region, hence the need to investigate the nexus between human capital and environmental [...] Read more.

This paper sought to examine the nexus between human capital and environmental sustainability in Southern African Development Community (SADC) countries. This contemporary topic has not received much attention in the region, hence the need to investigate the nexus between human capital and environmental sustainability. The paper used one of the most recent methodologies, namely, the pooled mean group (PMG) estimation technique, to assess this relationship from 1980 to 2021. The findings of the study are that human capital increases environmental sustainability in the long run in SADC countries. This implies that as human capital increases, countries will see an increase in technological innovations and research and development (R&D), enabling the mitigation of environmental degradation in the region. Therefore, it is imperative for the region to embark on human capital programs that improve environmental sustainability. Full article

(This article belongs to the Special Issue Decision Making in Resources Management: Problems, Methods and Tools)

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15 pages, 6298 KiB

Open AccessArticle

Flotation Recovery of Sphalerite in Sea Water: A Feasibility Study

by Alexander A. Nikolaev

Resources 2023, 12(4), 51; https://doi.org/10.3390/resources12040051 - 12 Apr 2023

Viewed by 1455

Abstract

Mining and mineral processing industry adversely affects ecosystems and communities in nearby areas, including high freshwater consumption and scarcity. That is why the emerging global trend is to use sea water in flotation to recover valuable minerals from finely disseminated base metals ores. [...] Read more.

Mining and mineral processing industry adversely affects ecosystems and communities in nearby areas, including high freshwater consumption and scarcity. That is why the emerging global trend is to use sea water in flotation to recover valuable minerals from finely disseminated base metals ores. Recent studies investigate sea water flotation of copper, molybdenum, nickel sulphides and pyrite, while flotation of sphalerite, the main valuable mineral for zinc production, remains uncovered. This paper examines the feasibility of sphalerite flotation by conventional collectors in artificial sea water using a bubble-particles technique and frothless flotation tests. Potassium isopropyl xanthate (PIPX) and sodium isopropyl dithiophosphate (SIDTP) were used as collectors, and copper sulphate was introduced as the activator, while zinc sulphate and sodium sulphide were used as depressants. We examined the most common size fractions of sphalerite: medium (−74 + 44 μm) and fines (−44 μm). The findings showed the feasibility of sphalerite flotation in artificial sea water. We also established correlations between the rate of bubble-particle attachment and the sphalerite flotation recovery resulting in the growth of flotation recovery with the increase of the bubble-particle attachment rate. The results can be used as guidelines in choosing flotation reagents for sphalerite flotation in sea water. Another practical application of the results is the potential for sustainable development of the industrial sector, ecosystems and societies due to the replacement of fresh water by sea water, although further technological and environmental studies are required. Full article

(This article belongs to the Special Issue Minerals and Land-Use Planning: Sustainable Narratives and Practices)

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14 pages, 1633 KiB

Open AccessFeature PaperArticle

Modern Technologies Providing a Full Cycle of Geo-Resources Development

by Cheynesh B. Kongar-Syuryun, Alexander V. Aleksakhin, Evgeniya N. Eliseeva, Anna V. Zhaglovskaya, Roman V. Klyuev and Denis A. Petrusevich

Resources 2023, 12(4), 50; https://doi.org/10.3390/resources12040050 - 11 Apr 2023

Cited by 25 | Viewed by 1842

Abstract

Resource-dependent countries and economies are found to be particularly sensitive to global shocks. A unifying parallel is drawn between resource-dependent countries and regions with depleted mineral resources. The objective factors of losses of accessed reserves are analyzed. A unifying parallel is drawn between [...] Read more.

Resource-dependent countries and economies are found to be particularly sensitive to global shocks. A unifying parallel is drawn between resource-dependent countries and regions with depleted mineral resources. The objective factors of losses of accessed reserves are analyzed. A unifying parallel is drawn between sub-standard ores and industrial waste. The paper proposes shifting geotechnology development from simple mineral extraction towards technologies that provide a full cycle of geo-resources development. A radical way of ensuring a full cycle of geo-resources development is the involvement of sub-standard ores and industrial waste in a closed processing cycle. The utilization of industrial waste without a valuable component extracting or reducing a harmful component to a background value is palliative. A comparative description of various technologies that allow extracting valuable components from sub-standard ores and industrial waste is made. The paper proposes a variant of chemical–physical technology that makes it possible to extract a valuable component from industrial waste to a minimum value. The activation of industrial waste with a disintegrator before a chemical extraction significantly increases the yield of a valuable component from 2.6 to 218.5%. A differentiated approach is needed regarding the choice of leaching solution, its percentage, as well as the leaching method and the need for activation processing of valuable components and industrial ones. The combined highly efficient physical–chemical and physical–technical technologies will ensure the maximum extraction of the valuable component from 52.6 to 98.8% in the full cycle of natural and industrial geo-resources development. Full article

(This article belongs to the Special Issue Resource Provision of the Sustainable Development under Global Shocks: 2022 Viewpoint)

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23 pages, 4334 KiB

Open AccessArticle

Assessment of Virtual Water Flows in Morocco’s Foreign Trade of Crop Products

by Abdeslam Boudhar, Said Boudhar, Mohamed Oudgou and Aomar Ibourk

Resources 2023, 12(4), 49; https://doi.org/10.3390/resources12040049 - 11 Apr 2023

Cited by 3 | Viewed by 2143

Abstract

As a semi-arid/arid country located in the northwest of Africa, Morocco is facing serious water scarcity driven by the dual stresses of decreasing availability of water resources and increasing water demands. Virtual water trade could be an effective tool to alleviate water scarcity. [...] Read more.

As a semi-arid/arid country located in the northwest of Africa, Morocco is facing serious water scarcity driven by the dual stresses of decreasing availability of water resources and increasing water demands. Virtual water trade could be an effective tool to alleviate water scarcity. The paper presents an analysis of the relationships between agrarian productions, foreign trade, and the water sector in Morocco by deriving a comprehensive estimate of virtual water export and import in Morocco’s foreign trade of 40 crop products during the period from 2000 to 2017. Our objectives include determining the intensity of water consumption of exported and imported crop products and quantifying the water consumed and saved, respectively, by locally producing and importing these products. To this end, FAO’s Penman-Monteith climate model was used to estimate crop water requirements based on data on meteorological factors. The results show that Morocco was a net virtual water importer during the study period. The deficit was 595.74 Gm³. The tendency of total virtual water export was on a rising trend, while the total virtual water import was on a downward trend. The main exported virtual water was from vegetables (68.87 Gm³, 72.47%) and the main imported virtual water was from cereals (679.68 Gm³, 98.4%). Regarding crop product’s water intensity, we found that the exported crop products were excessively concentrated on water-intensive products such as mandarins and clementines, figs, oranges, apricots, plums, citrus fruits, olives, tomatoes, asparagus, peas, and artichokes. On the other hand, the agricultural policy of 2009–2020 increased the production of water-intensive products. This finding seems to be going against the virtual water trade theory, which states that water-poor countries should import water-intensive products and produce local products with lower water requirements. Full article

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22 pages, 2078 KiB

Open AccessArticle

Evaluation of Sourcing Decision for Hydrogen Supply Chain Using an Integrated Multi-Criteria Decision Analysis (MCDA) Tool

by Kasin Ransikarbum, Wattana Chanthakhot, Tony Glimm and Jettarat Janmontree

Resources 2023, 12(4), 48; https://doi.org/10.3390/resources12040048 - 10 Apr 2023

Cited by 9 | Viewed by 2002

Abstract

The use of fossil fuels has caused many environmental issues, including greenhouse gas emissions and associated climate change. Several studies have focused on mitigating this problem. One dynamic direction for emerging sources of future renewable energy is the use of hydrogen energy. In [...] Read more.

The use of fossil fuels has caused many environmental issues, including greenhouse gas emissions and associated climate change. Several studies have focused on mitigating this problem. One dynamic direction for emerging sources of future renewable energy is the use of hydrogen energy. In this research, we evaluate the sourcing decision for a hydrogen supply chain in the context of a case study in Thailand using group decision making analysis for policy implications. We use an integrative multi-criteria decision analysis (MCDA) tool which includes an analytic hierarchy process (AHP), fuzzy AHP (FAHP), and data envelopment analysis (DEA) to analyze weighted criteria and sourcing alternatives using data collected from a group of selected experts. A list of criteria related to sustainability paradigms and sourcing decisions for possible use of hydrogen energy, including natural gas, coal, biomass, and water, are evaluated. Our results reveal that political acceptance is considered the most important criterion with a global weight of 0.514 in the context of Thailand. Additionally, natural gas is found to be the foreseeable source for hydrogen production in Thailand with a global weight of 0.313. We also note that the analysis is based on specific data inputs and that an alternative with a lower score does not imply that the source is not worth exploring. Full article

(This article belongs to the Special Issue Decision Making in Resources Management: Problems, Methods and Tools)

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25 pages, 10693 KiB

Open AccessArticle

Hydrochemical Indicator Analysis of Seawater Intrusion into Coastal Aquifers of Semiarid Areas

by Jobst Wurl, Miguel Angel Imaz-Lamadrid, Lía Celina Mendez-Rodriguez and Pablo Hernández-Morales

Resources 2023, 12(4), 47; https://doi.org/10.3390/resources12040047 - 07 Apr 2023

Cited by 1 | Viewed by 1768

Abstract

Saltwater intrusion into groundwater systems is a problem worldwide and is induced mainly by human activities, such as groundwater overexploitation and climate change. The coastal Los Planes aquifer in the southern part of the Baja California Peninsula (Mexico) is affected by seawater intrusion [...] Read more.

Saltwater intrusion into groundwater systems is a problem worldwide and is induced mainly by human activities, such as groundwater overexploitation and climate change. The coastal Los Planes aquifer in the southern part of the Baja California Peninsula (Mexico) is affected by seawater intrusion due to more than 40 years of groundwater overexploitation. A dataset of 55 samples was compiled, including 18 samples from our campaigns between 2014 and 2016. Several methods exist to define the impact of seawater in a coastal aquifer, such as the “seawater fraction”, the “Chloro-Alkaline Indices”, the “Hydrochemical Facies Evolution Diagram”, and the “Saltwater Mixing Index”. These methods provide reasonable results for most of the coastal zone of the Los Planes aquifer. A slight increase in mineralization was observed from 2014 to 2016 compared with the situation in 2003. However, in its northwestern part, samples from hydrothermal wells were not recognized by these methods. Here, the aquifer is affected mainly by thermal water with elevated mineralization, introduced through the El Sargento fault, a main fault, which cuts through the study area in the north–south direction. By considering known hydrothermal manifestations in the interpretation, samples could be classified as a combination of four end-members: fresh groundwater, seawater, and the composition of two types of thermal water. One thermal endmember with very low mineralization coincides with the thermal water described from the Los Cabos Block, where meteoric water represents the source (found in the Sierra la Laguna). The second endmember is comparable to coastal thermal manifestations where seawater represents the main source. Therefore, the higher mineralization in the northwestern zone is the result of the mobilization of thermal groundwater and direct mixing with seawater, which is introduced locally at the coast due to overextraction. This finding is important for future management strategies of the aquifer. Full article

(This article belongs to the Special Issue Advances in Water Resource Monitoring and Modelling: Water Quantity and Quality Issues)

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14 pages, 4409 KiB

Open AccessArticle

Use of a Convolutional Neural Network for Predicting Fuel Consumption of an Agricultural Tractor

by Hamid Jalilnezhad, Yousef Abbaspour-Gilandeh, Vali Rasooli-Sharabiani, Aref Mardani, José Luis Hernández-Hernández, José Antonio Montero-Valverde and Mario Hernández-Hernández

Resources 2023, 12(4), 46; https://doi.org/10.3390/resources12040046 - 31 Mar 2023

Cited by 2 | Viewed by 1564

Abstract

The energy crisis and depleting fossil fuel resources have always been the focus of researchers. Fuel consumption of agricultural tractors is not an exception. Researchers have used different methods to predict fuel consumption. With the development of artificial intelligence in the last decade, [...] Read more.

The energy crisis and depleting fossil fuel resources have always been the focus of researchers. Fuel consumption of agricultural tractors is not an exception. Researchers have used different methods to predict fuel consumption. With the development of artificial intelligence in the last decade, all re-searchers’ attention has been directed towards it. Deep learning is a subset of machine learning, which was inspired by the data processing patterns in the human brain. The deep learning method has been used in research due to the advantages of high accuracy and generalization. So far, no research has used this method to predict fuel consumption. In this research, field experiments were carried out in sandy clay loam and clay soils to model the temporal fuel consumption and specific fuel consumption of an agricultural tractor using a convolutional neural network (CNN), while having some parameters such as the soil type, soil conditions, tool parameters, and operation pa-rameters. The experiments were conducted within each soil texture in a factorial manner based on the randomized complete block design (RCBD) with three replicates. For each soil texture, various moisture levels (8–17% for dry and 18–40% for moist soils), tractor forward speeds (1.2, 1.6, 1.8, and 2.2 km h⁻¹), working depths (30 and 50 cm), the number of passes (2 and 6), and tire inflation pressure (20 and 25 psi) were selected, and cone index, dynamic load, and moisture content were measured in each experimental section. The designed networks used to predict the instant fuel consumption were of a CNN type. The results indicated that the network developed based on the Sgdm algorithm outperformed the others, and thus it was selected for modeling purposes. The network was evaluated based on R² and MSE criteria. For the temporal fuel consumption, the best results were obtained while using 8-510-510-1 architecture with R² = 0.9729 and MSE = 0.0049. The 8-100-95-1 architecture also led to the best prediction of the specific fuel consumption with R² of 0.9737 and MSE of 0.0054. The high prediction accuracy and low error in this research compared to previous studies indicate the superiority of this method in order to predict fuel consumption. It was also observed from the results that the input parameters, which include soil, tool, and operational parameters, are all effective on fuel consumption. Proper management of some parameters, such as working depth, tire inflation pressure, and forward speed, can help to optimize fuel consumption. Full article

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24 pages, 2820 KiB

Open AccessReview

Automotive Paint Sludge: A Review of Pretreatments and Recovery Options

by Barbara Ruffino, Giuseppe Campo, Siti Shawalliah Idris, Güray Salihoğlu and Mariachiara Zanetti

Resources 2023, 12(4), 45; https://doi.org/10.3390/resources12040045 - 31 Mar 2023

Viewed by 4313

Abstract

Automotive paint sludge (PS) is the waste product generated in the painting process of vehicle bodies. Although automotive spray painting is an automated operation, its efficiency is still quite low, since approximately 40–50% of the employed paint does not reach the target and, [...] Read more.

Automotive paint sludge (PS) is the waste product generated in the painting process of vehicle bodies. Although automotive spray painting is an automated operation, its efficiency is still quite low, since approximately 40–50% of the employed paint does not reach the target and, after being mixed with the collecting water, becomes PS. PS is a very complex material that contains several organic and inorganic components, in addition to 90% water immediately after production. Italian automotive factories produce from 2.5 to 5.0 kg of PS per painted car. If that figure is related to the number of vehicles produced worldwide every year, in the order of 100 million, it determines an annual PS amount in the order of 200,000–500,000 t. Consequently, a proper final destination for PS must be found. The waste management hierarchy and the principles of the circular economy require that we privilege solutions that foresee the recovery of valuable products or energy. This paper first reviews the processes and the machines that have been recently developed to obtain an enhanced mechanical dewatering of PS. The pretreatment of PS dewatering is often crucial in order to obtain high efficiency in the subsequent recovery process. Afterwards, the paper presents and discusses the recovery options that have been proposed and tested, at different scales, by several authors in the last thirty years. The processes for PS management can be grouped as follows: (i) direct employment of physically/chemically treated PS in the production of primers and sealants; (ii) utilization of PS for the production of building materials, as supplementary components of cement concrete, mortar, or bituminous mixtures; (iii) extraction of valuable organic and inorganic products by using thermal processes (pyrolysis, gasification); (iv) biological processes for PS detoxification, metal recovery, and stabilization before landfilling. Full article

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15 pages, 4383 KiB

Open AccessArticle

Collecting Rocks on the Frontier: Investigating the Geodiversity Significance of Historical Building Stones and Rock Collecting at the Maxey Homestead, Northwest Texas, USA

by Stance Hurst, Doug Cunningham and Eileen Johnson

Resources 2023, 12(4), 44; https://doi.org/10.3390/resources12040044 - 29 Mar 2023

Cited by 2 | Viewed by 1722

Abstract

The geoheritage importance of the stones used in the construction of buildings in urban landscapes has been documented by several scholars around the world. Building stones can provide an ex situ cross-section of a region’s geodiversity and illuminate its cultural significance. Research at [...] Read more.

The geoheritage importance of the stones used in the construction of buildings in urban landscapes has been documented by several scholars around the world. Building stones can provide an ex situ cross-section of a region’s geodiversity and illuminate its cultural significance. Research at the historic Maxey Homestead (1902–1907), located along the eastern escarpment of the Southern High Plains near Post, Texas, has uncovered a rock collection gathered from local sources. In addition, rocks from the eastern escarpment were used to construct and decorate a house in 1938 (~9 km to the north) after the Maxeys moved from their original homestead. A combination of GIS and 3D mapping using an unmanned aerial vehicle were used to assess and analyze the geodiversity significance of the rock collection and rock-decorated house. Rock collecting and the use of local stones in building construction provide insights into the geodiversity of the Southern High Plains’ eastern escarpment and the historical geoheritage of northwest Texas in the early 20th century. The results of this study also demonstrate the importance of examining non-urban and historical landscapes for elucidating the significance of geodiversity to past peoples. Full article

(This article belongs to the Special Issue Geodiversity Assessment: What, Why and How?)

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13 pages, 3502 KiB

Open AccessTechnical Note

Experimental Study of District Heating Substations in a Hardware-in-the-Loop Test Rig

by Anna Vannahme, Jonas Busch, Mathias Ehrenwirth and Tobias Schrag

Resources 2023, 12(4), 43; https://doi.org/10.3390/resources12040043 - 26 Mar 2023

Viewed by 1382

Abstract

This study compares two district heating substation systems for implementation in rural district heating networks with non-retrofitted single- and two-family houses. The aim is to determine which system has the potential to provide lower return temperatures and/or lower power peak demand. A hardware-in-the-loop-test [...] Read more.

This study compares two district heating substation systems for implementation in rural district heating networks with non-retrofitted single- and two-family houses. The aim is to determine which system has the potential to provide lower return temperatures and/or lower power peak demand. A hardware-in-the-loop-test rig was utilized to measure the two district heating substations under real operation conditions. This experimental study demonstrates that load balancing of the district heating network is attainable with the district heating substation with storage. This is especially advantageous when there is a high demand for domestic hot water. Overall, both systems yield comparable return temperatures. Full article

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