Resources

23 pages, 9046 KiB

Open AccessFeature PaperArticle

Evaluation of Wetland Area Effects on Hydrology and Water Quality at Watershed Scale

by Dipesh Nepal, Prem Parajuli, Ying Ouyang, Filip To, Nuwan Wijewardane and Vivek Venishetty

Resources 2024, 13(8), 114; https://doi.org/10.3390/resources13080114 - 22 Aug 2024

Viewed by 1552

Change in land use and land cover (LULC) is crucial to freshwater ecosystems as it affects surface runoff, groundwater storage, and sediment and nutrient transport within watershed areas. Ecosystem components such as wetlands, which can contribute to the reduction of water pollution and [...] Read more.

Change in land use and land cover (LULC) is crucial to freshwater ecosystems as it affects surface runoff, groundwater storage, and sediment and nutrient transport within watershed areas. Ecosystem components such as wetlands, which can contribute to the reduction of water pollution and the enhancement of groundwater recharge, are altered by LULC modifications. This study evaluates how wetlands in the Big Sunflower River Watershed (BSRW) have changed in recent years and quantified their impacts on streamflow, water quality, and groundwater storage using the Soil and Water Assessment Tool (SWAT). The model was well calibrated and validated prior to its application. Our study showed that the maximum increase in wetland areas within the sub-watersheds of interest was 26% from 2008 to 2020. The maximum changes in reduction due to the increase in wetland areas were determined by 2% for streamflow, 37% for total suspended solids, 13% for total phosphorus (TP), 4% for total nitrogen (TN), and the maximum increase in shallow groundwater storage by 90 mm from 2008 to 2020 only in the selected sub-basins. However, the central part of the watershed experienced average declines of groundwater levels up to 176 mm per year due to water withdrawal for irrigation or other uses. This study also found that restoration of 460 to 550 ha of wetlands could increase the reduction of discharge by 20%, sediment by 25%, TN by 18%, and TP by 12%. This study highlights the importance of wetland conservation for water quality improvement and management of groundwater resources. Full article

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30 pages, 8276 KiB

Open AccessArticle

Land Use/Cover Classification of Large Conservation Areas Using a Ground-Linked High-Resolution Unmanned Aerial Vehicle

by Lazaro J. Mangewa, Patrick A. Ndakidemi, Richard D. Alward, Hamza K. Kija, Emmanuel R. Nasolwa and Linus K. Munishi

Resources 2024, 13(8), 113; https://doi.org/10.3390/resources13080113 - 22 Aug 2024

Viewed by 834

Abstract

High-resolution remote sensing platforms are crucial to map land use/cover (LULC) types. Unmanned aerial vehicle (UAV) technology has been widely used in the northern hemisphere, addressing the challenges facing low- to medium-resolution satellite platforms. This study establishes the scalability of Sentinel-2 LULC classification [...] Read more.

High-resolution remote sensing platforms are crucial to map land use/cover (LULC) types. Unmanned aerial vehicle (UAV) technology has been widely used in the northern hemisphere, addressing the challenges facing low- to medium-resolution satellite platforms. This study establishes the scalability of Sentinel-2 LULC classification with ground-linked UAV orthoimages to large African ecosystems, particularly the Burunge Wildlife Management Area in Tanzania. It involved UAV flights in 19 ground-surveyed plots followed by upscaling orthoimages to a 10 m × 10 m resolution to guide Sentinel-2 LULC classification. The results were compared with unguided Sentinel-2 using the best classifier (random forest, RFC) compared to support vector machines (SVMs) and maximum likelihood classification (MLC). The guided classification approach, with an overall accuracy (OA) of 94% and a kappa coefficient (k) of 0.92, outperformed the unguided classification approach (OA = 90%; k = 0.87). It registered grasslands (55.2%) as a major vegetated class, followed by woodlands (7.6%) and shrublands (4.7%). The unguided approach registered grasslands (43.3%), followed by shrublands (27.4%) and woodlands (1.7%). Powerful ground-linked UAV-based training samples and RFC improved the performance. The area size, heterogeneity, pre-UAV flight ground data, and UAV-based woody plant encroachment detection contribute to the study’s novelty. The findings are useful in conservation planning and rangelands management. Thus, they are recommended for similar conservation areas. Full article

(This article belongs to the Topic Innovative and Critical Issues in Natural Resource Management and Exploitation)

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17 pages, 6754 KiB

Open AccessArticle

Utilizing Circular Economy Policies to Maintain and Transform Mining Facilities: A Case Study of Brzeszcze, Poland

by Anna Szewczyk-Świątek, Anna Ostręga, Marek Cała and Pascal Beese-Vasbender

Resources 2024, 13(8), 112; https://doi.org/10.3390/resources13080112 - 22 Aug 2024

Cited by 1 | Viewed by 1259

Abstract

How is the circular economy policy utilised to transform mining facilities? This paper analyses projects undertaken under increasing pressure for economic and energy transformation (transitioning away from coal), using the example of the municipality of Brzeszcze in Poland. These projects highlight the planned [...] Read more.

How is the circular economy policy utilised to transform mining facilities? This paper analyses projects undertaken under increasing pressure for economic and energy transformation (transitioning away from coal), using the example of the municipality of Brzeszcze in Poland. These projects highlight the planned key spatial initiatives deemed feasible for implementation in the area, emphasising mining facilities and waste management (including waste from outgoing industries) that can break or speed transformation. The article aims to analyse solutions considered viable for implementation in mining towns, which can contribute to a better understanding of transformations in other monofunctional industrial centres in Europe. Data were collected using the research by design method. It is concluded that stakeholders perceive the development of peripheral mining areas as an action that can significantly impact the conduct and perception of activities related to the circular economy while also promoting a gradual transition away from coal mining. The article highlights the role of initiatives enabling the combination of transformations with a slowdown in the pace of mining activity cessation, considering the need for waste management, energy transformation, and the financial and energy stability of urban centres that have long relied on coal. Full article

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

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19 pages, 4309 KiB

Open AccessArticle

An Evaluation of the Land Available for Sustainable Sugarcane Cultivation and Potential for Producing Ethanol and Bioelectricity in Angola

by Adilson João Matias, Luiz Augusto Horta Nogueira and Eric Alberto Ocampo Batlle

Resources 2024, 13(8), 111; https://doi.org/10.3390/resources13080111 - 17 Aug 2024

Viewed by 1610

Abstract

With a predominantly humid tropical climate and a large area for expanding agricultural activities, Angola has in principle favorable conditions for bioenergy production. The focus of this study was to evaluate the availability of suitable land for producing sugarcane. This crop is highly [...] Read more.

With a predominantly humid tropical climate and a large area for expanding agricultural activities, Angola has in principle favorable conditions for bioenergy production. The focus of this study was to evaluate the availability of suitable land for producing sugarcane. This crop is highly efficient in converting solar energy into biomass for energy purposes in Angola. To this end, this paper outlines a method for data collection, processing, and analysis divided into three sections. The first section uses the GAEZ (Global Agroecological Zones) database and QGIS (Quantum GIS) software (version 3.22.5) to assess land availability for sugarcane cultivation in Angola, classifying the regions’ suitability into four levels. The second section supplements this with data from the FAOSTAT database, systematically excluding areas with restrictions, such as protected zones, land already used for other crops, and regions unsuitable for sugarcane. Finally, the third section employs an agricultural yield model to estimate the potential yield of sugarcane based on climatic parameters and the amount of bioenergy (ethanol and bioelectricity) able to be produced in the available land. Under these criteria, this study identified the existence of 6.3 Mha in lands of good agricultural suitability, with water resources, corresponding to 5% of the Angolan territory, distributed in seven provinces of the country, especially in the provinces of Cuando Cubango and Cunene, where 85% of the very suitable land under irrigation is located. Adopting a model of agricultural productivity, assuming irrigation and adequate agricultural practices, such area could produce approximately 956 million tons of sugarcane annually, which is significantly higher than the current production in this country. This amount of feedstock processed using current technology could potentially produce 81.3 GL of ethanol and 176.9 TWh of electricity with low GHG emissions per year, which is able to mitigate, as a whole, circa 60.3 MtCO₂-eq/year by displacing gasoline in light vehicles and diesel and natural gas consumed in power generation. Full article

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16 pages, 2610 KiB

Open AccessArticle

Mathematical Modeling for Predicting Growth and Yield of Halophyte Hedysarum scoparium in Arid Regions under Variable Irrigation and Soil Amendment Conditions

by Ahmad Azeem and Wenxuan Mai

Resources 2024, 13(8), 110; https://doi.org/10.3390/resources13080110 - 12 Aug 2024

Viewed by 1081

Abstract

Growing degree days (GDDs) and leaf area index (LAI) greatly influence the growth and yield of many crops grown in arid regions. Therefore, variation in LAI due to GDD can provide a theoretical basis for predicting crop growth, water consumption, plant development, and [...] Read more.

Growing degree days (GDDs) and leaf area index (LAI) greatly influence the growth and yield of many crops grown in arid regions. Therefore, variation in LAI due to GDD can provide a theoretical basis for predicting crop growth, water consumption, plant development, and yield in arid agriculture via the development of mathematical growth models. This study described the relationship between plant biomass production and variation in LAI due to GDD in arid regions under different types of irrigation (fresh water and saline water) and soils amended with different substances (manure+sandy soil, compost+sandy soil, clay+sandy soil, and sandy soil). Mathematical models for LAI were established for GDDs. In addition, different water quality irrigation techniques were used as independent variables to calculate the LAI of halophytic plants (Hedysarum scoparium) in arid regions under different soil amendment treatments. Furthermore, mathematical models for plant biomass production were developed by using the LAI and GDDs. For this purpose, Logistic, Gaussian, modified Gaussian, and Cubic polynomial models were used. Modified Gaussian and Cubic polynomial models are the best among all developed models, but Cubic polynomial models are more suitable among all developed models because of their simple quadratic equations that can be solved by using the first derivative. It was observed that with increased salt concentration in the irrigation water, the growth of per plant production decreased. However, soil amendments like manure and compost enhance salt tolerance against salt stress and enable plants to sustain their growth. Furthermore, Hedysarum scoparium attains maximum LAI when its GDD is about 1117.5 °C under both irrigation regimes and in all soil amendment treatments. It was concluded that these predicted mathematical models can provide crucial insights for enhancing production in arid regions by using eco-friendly soil amendments to improve water use efficiency across diverse types of water irrigation. Full article

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23 pages, 48615 KiB

Open AccessArticle

Precious and Base Metal Minerals in Black Sands of the Egyptian Mediterranean Coast: Mineralogical and Geochemical Attributes

by Abdel-Aal M. Abdel-Karim and Ahmed Gad

Resources 2024, 13(8), 109; https://doi.org/10.3390/resources13080109 - 9 Aug 2024

Viewed by 1322

Abstract

This paper investigates the mineralogical and geochemical characteristics, as well as the possible sources, of gold, silver, platinum group elements (PGE), copper, and lead found in the beach sands along Egypt’s Mediterranean coast. Using scanning electron microscopy and electron probe micro-analysis, this study [...] Read more.

This paper investigates the mineralogical and geochemical characteristics, as well as the possible sources, of gold, silver, platinum group elements (PGE), copper, and lead found in the beach sands along Egypt’s Mediterranean coast. Using scanning electron microscopy and electron probe micro-analysis, this study determines the morphology and micro-chemistry of separated grains to assess their economic potential and how various minerals respond to different transport distances. The analysis reveals that gold grains are of high purity (94.11 to 98.55 wt.%; average 96 wt.% Au) and are alloyed with Ag (1.28–2.32 wt.%) and Cu (0.16–3.15 wt.%). Two types of gold grains were identified, indicating differences in transport distances. Variations in morphology, surface features, inclusion types, rims, and chemistry of the native metals, including gold grains, suggest differences in composition, weathering degree, transport distance, deposit types, and host rocks. The average Ag concentration in gold grains (1.86 wt.%) suggests a link to mesothermal or supergene deposits. Most silver, copper, and lead grains are spherical, with some variations in shape. Silver grains have 71.66–95.34 wt.% Ag (avg. 82.67 wt.%). Copper grains have 92.54–98.42 wt.% Cu (avg. 94.22 wt.%). Lead grains contain 74.22–84.45 wt.% Pb (avg. 79.26 wt.%). The identified platinum group minerals (PGM) belong to the Pt–Fe alloys and sperrylite, both of which are PPGE-bearing minerals. These metals likely originate from the weathering of upstream Nile tributaries surrounded by igneous and metamorphic rocks from Ethiopian and Central African regions, with a minor contribution from the Egyptian Eastern Desert Mountains. Full article

(This article belongs to the Special Issue Mineral Resource Management 2023: Assessment, Mining and Processing)

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37 pages, 4765 KiB

Open AccessArticle

Increasing the Sustainability of the Strategic Development of Oil Producing Companies in Mexico

by Tatyana Semenova and Juan Yair Martínez Santoyo

Resources 2024, 13(8), 108; https://doi.org/10.3390/resources13080108 - 1 Aug 2024

Viewed by 1794

Abstract

In the oil industry, there is a gap between the goals of sustainable development, the implementation of oil projects and its specific consequences. Oil projects are implemented in isolation from other variables, have an insufficiently targeted impact on the territory and often have [...] Read more.

In the oil industry, there is a gap between the goals of sustainable development, the implementation of oil projects and its specific consequences. Oil projects are implemented in isolation from other variables, have an insufficiently targeted impact on the territory and often have a negative impact on the environment. The purpose of the study is to improve the efficiency of oil producing companies and increase their contribution to the development of the country’s economy as a whole. The methodology used in this article is based on the concept of sustainable development, systemic and integrated approaches, methodology of sub-potentials and modeling of business processes of a circular economy. The results of the study include a methodological approach to the formation of an effective business model for oil companies. We propose this methodological approach to select the projects of oil companies, taking into account economic, environmental and other factors, and the most promising prospects for Mexico. The significance of the study is that the proposed methodology makes it possible to increase the sustainability of the development of oil companies and integrate their business processes into the task of increasing the efficiency of operation and development of the territory. The novelty of the study lies in the application of the concept of sub-potentials and the calculation of critical indicator values for oil producing companies in Mexico to prevent the transition of sub-potentials of functioning and development into sub-potentials of threat and containment during project implementation. Full article

(This article belongs to the Topic Energy Management and Sustainable Development from Economic, Social and Environmental Aspects)

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22 pages, 2521 KiB

Open AccessArticle

Investigating of Spatial Urban Growth Pattern and Associated Landscape Dynamics in Congolese Mining Cities Bordering Zambia from 1990 to 2023

by Yannick Useni Sikuzani, Médard Mpanda Mukenza, François Malaisse and Jan Bogaert

Resources 2024, 13(8), 107; https://doi.org/10.3390/resources13080107 - 29 Jul 2024

Cited by 1 | Viewed by 1090

Abstract

This study investigates the spatial urban growth patterns of cities along the Democratic Republic of the Congo (DRC) and Zambia border, a region of significant economic importance characterized by cross-border trade. This activity has led to rapid but unplanned urban growth. The objective [...] Read more.

This study investigates the spatial urban growth patterns of cities along the Democratic Republic of the Congo (DRC) and Zambia border, a region of significant economic importance characterized by cross-border trade. This activity has led to rapid but unplanned urban growth. The objective is to quantify the spatial expansion of Congolese cities (Kipushi, Kasumbalesa, Mokambo, and Sakania) bordering Zambia and to evaluate associated landscape changes. The methodology of this study includes the supervised classification of Landsat images with a spatial resolution of 30 m for the years 1990, 2000, 2010, and 2023. This classification was validated using field data. Subsequently, landscape metrics such as class area, patch number, Shannon diversity index, disturbance index, urban expansion intensity index, largest patch index, and mean Euclidean distance were calculated for each city and each date. The results reveal substantial landscape transformations in the border cities between 1990 and 2023. These changes are primarily driven by rapid urban expansion, particularly pronounced in Kasumbalesa. Between 1990 and 2023, forest cover declined from 70% to less than 15% in Kipushi, from 80% to 10% in Kasumbalesa, from 90% to 30% in Mokambo, and from 80% to 15% in Sakania. This forest cover loss is accompanied by an increase in landscape element diversity, as indicated by the Shannon diversity index, except in Kipushi, suggesting a transition towards more heterogeneous landscapes. In these border cities, landscape dynamics are also characterized by the expansion of agriculture and savannas, highlighted by an increase in the disturbance index. Analysis of spatial pattern changes shows that built-up areas, agriculture, and savannas exhibit trends of patch creation or aggregation, whereas forests are undergoing processes of dissection and patch attrition. Congolese cities bordering Zambia are undergoing substantial spatial changes propelled by intricate interactions between economic, demographic, and infrastructural factors. Our results underscore the need for sustainable development strategies to address urban sprawl through smart growth policies and mixed-use developments, mitigate deforestation via stricter land use regulations and reforestation projects, and enhance cross-border cooperation through joint environmental management and collaborative research initiatives. Full article

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

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19 pages, 2714 KiB

Open AccessArticle

Evaluating the Effects of Parameter Uncertainty on River Water Quality Predictions

by André Fonseca, Cidália Botelho, Rui A. R. Boaventura and Vítor J. P. Vilar

Resources 2024, 13(8), 106; https://doi.org/10.3390/resources13080106 - 26 Jul 2024

Viewed by 1079

Abstract

Due to the high uncertainty of model predictions, it is often challenging to draw definitive conclusions when evaluating river water quality in the context of management options. The major aim of this study is to present a statistical evaluation of the Hydrologic Simulation [...] Read more.

Due to the high uncertainty of model predictions, it is often challenging to draw definitive conclusions when evaluating river water quality in the context of management options. The major aim of this study is to present a statistical evaluation of the Hydrologic Simulation Program FORTRAN (HSPF), which is a water quality modeling system, and how this modeling system can be used as a valuable tool to enhance monitoring planning and reduce uncertainty in water quality predictions. The authors’ findings regarding the sensitivity analysis of the HSPF model in relation to water quality predictions are presented. The application of the computer model was focused on the Ave River watershed in Portugal. Calibration of the hydrology was performed at two stations over five years, starting from January 1990 and ending in December 1994. Following the calibration, the hydrology model was then validated for another five-year period, from January 1995 to December 1999. A comprehensive evaluation framework is proposed, which includes a two-step statistical evaluation based on commonly used hydrology criteria for model calibration and validation. To thoroughly assess model uncertainty and parameter sensitivity, a Monte Carlo method uncertainty evaluation approach is integrated, along with multi-parametric sensitivity analyses. The Monte Carlo simulation considers the probability distributions of fourteen HSPF water quality parameters, which are used as input factors. The parameters that had the greatest impact on the simulated in-stream fecal coliform concentrations were those that represented the first-order decay rate and the surface runoff mechanism, which effectively removed 90 percent of the fecal coliform from the pervious land surface. These parameters had a more significant influence compared to the accumulation and maximum storage rates. When it comes to the oxygen governing process, the parameters that showed the highest sensitivity were benthal oxygen demand and nitrification/denitrification rate. The insights that can be derived from this study play a critical role in the development of robust water management strategies, and their significance lies in their potential to contribute to the advancement of predictive models in the field of water resources. Full article

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16 pages, 1873 KiB

Open AccessArticle

Assessment of Environmental Pollution and Risks Associated with Tailing Dams in a Historical Gold Mining Area of Ecuador

by Bryan Salgado-Almeida, Arián Briones-Escalante, Daniel Falquez-Torres, Karla Filián-Haz, Fredy Guzmán-Martínez, Kenny Escobar-Segovia, Elizabeth Peña-Carpio and Samantha Jiménez-Oyola

Resources 2024, 13(8), 105; https://doi.org/10.3390/resources13080105 - 25 Jul 2024

Viewed by 1881

Abstract

Tailings are a significant concern due to their potential release of toxic elements into the environment, posing risks to ecosystems and human health. Therefore, understanding their polluting potential is crucial for effective mitigation strategies. This study evaluates the contaminating potential of eight tailing [...] Read more.

Tailings are a significant concern due to their potential release of toxic elements into the environment, posing risks to ecosystems and human health. Therefore, understanding their polluting potential is crucial for effective mitigation strategies. This study evaluates the contaminating potential of eight tailing dams in the upper basin of the Puyango River in southern Ecuador. A physicochemical and mineralogical characterization of the tailings was conducted. The contents of As, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, Se, V, and Zn were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The contamination index (IC) and the risk (R_I) to the environment and population were evaluated. As a result, it was found that As, Cu, Pb, Se, and Zn exceeded the maximum permissible limits in all the samples according to Ecuadorian regulations. Six of the eight tailing dams presented very high pollution levels (21.28 < IC < 298.61), indicating a severe contamination risk. As, Sb, and Se were the most significant contributors to the index, with 29%, 31%, and 20% contribution to the overall IC, respectively. However, the risk assessment indicated a low risk (R_I < 5) to both the population and the natural environment, mainly due to the distance between the tailing dams and the potential receptors. While the present risk associated with the studied tailing dams is low, there exists potential for long-term escalation. Full article

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14 pages, 741 KiB

Open AccessArticle

Characterization of Beech Wood Pellets as Low-Emission Solid Biofuel for Residential Heating in Serbia

by Vasilije Matijašević, Zdeněk Beňo, Viktor Tekáč and Van Minh Duong

Resources 2024, 13(8), 104; https://doi.org/10.3390/resources13080104 - 25 Jul 2024

Viewed by 1395

Abstract

This study evaluated the suitability of two types of beech wood pellets as renewable, low-emission biofuel sources in order to combat the energy mix and poor air quality in Serbia. Key solid biofuel characteristics, including the heating values (18.5–18.7 MJ/kg), moisture content (5.54–7.16%), [...] Read more.

This study evaluated the suitability of two types of beech wood pellets as renewable, low-emission biofuel sources in order to combat the energy mix and poor air quality in Serbia. Key solid biofuel characteristics, including the heating values (18.5–18.7 MJ/kg), moisture content (5.54–7.16%), and volatile matter (82.4–84.4%) were assessed according to established standards. The elemental composition (mass fractions of 48.26–48.53% carbon, 6% hydrogen, 0.12–0.2% nitrogen, 0.02% sulfur, non-detected chlorine) and ash content (0.46–1.2%) demonstrated that the analyzed beech pellets met the criteria for high-quality classification, aligning with the ENplus A1 and ENplus A2 standards. The emissions of O₂, CO₂, CO, NO_x, SO₂, and TOC were quantified in the flue gas of an automatic residential pellet stove and compared with the existing literature. While combustion of the beech pellets yielded low emissions of SO₂ (6 mg/m³) and NO_x (188 mg/m³), the fluctuating CO (1456–2064 mg/m³) and TOC (26.75–61.46 mg/m³) levels were influenced by the appliance performance. These findings underscore the potential of beech wood pellets as a premium solid biofuel option for Serbian households, offering implications for both end-users and policymakers. Full article

(This article belongs to the Topic Energy Management and Sustainable Development from Economic, Social and Environmental Aspects)

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11 pages, 17344 KiB

Open AccessArticle

Mechanical Performance of Bentonite Plugs in Abandonment Operations of Petroleum Wells

by Laura Rafaela Cavalcanti de Oliveira, Mário César de Siqueira Lima, Waleska Rodrigues Pontes da Costa, Ruth Luna do Nascimento Gonçalves, Anna Carolina Amorim Costa, Karine Castro Nóbrega, Elessandre Alves de Souza and Luciana Viana Amorim

Resources 2024, 13(8), 103; https://doi.org/10.3390/resources13080103 - 23 Jul 2024

Viewed by 916

Abstract

This study aims to evaluate how the operational procedure adopted for pellet placement and the exposure to subsurface conditions influence the mechanical integrity of bentonite plugs used as barrier elements in the abandonment of petroleum wells. To this end, the plugs were formed [...] Read more.

This study aims to evaluate how the operational procedure adopted for pellet placement and the exposure to subsurface conditions influence the mechanical integrity of bentonite plugs used as barrier elements in the abandonment of petroleum wells. To this end, the plugs were formed by hydrating the pellets directly in water, simulating the onshore procedure, while the offshore plugs were obtained from pellets hydrated in deionized water after immersion in diesel or olefin, which are suggested as displacement fluids. The plugs obtained were tested by compression and adhesion tests. These mechanical tests were also carried out for specimens obtained from plugs exposed to four formulations of synthetic formation waters. The results obtained demonstrated that, in the offshore procedure, the previous contact with olefin may adversely affects the mechanical stability of bentonite plugs, while plugs formed from pellets immersed in diesel presented satisfactory mechanical properties. However, the contact with formation water evidenced that the onshore plug presents superior resistance than the offshore plug previously immersed in diesel. The highly successful performance of the onshore plug was attested by the maintenance of the compressive strength, which exhibited a maximum reduction of 13%, even after exposure to the most saline formation waters. Full article

(This article belongs to the Topic Petroleum and Gas Engineering)

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17 pages, 5670 KiB

Open AccessArticle

Spray-Dried Jaboticaba Powder as Food Resource

by Neiton C. Silva, Gabriela B. Andrade and Marcos A. S. Barrozo

Resources 2024, 13(8), 102; https://doi.org/10.3390/resources13080102 - 23 Jul 2024

Viewed by 1141

Abstract

Jaboticaba, a popular Brazilian fruit, has recently garnered scientific interest due to its nutritional properties and high levels of bioactive compounds. However, this fruit is highly perishable due to its high moisture content and physical–chemical structure. Therefore, it is imperative to employ methods [...] Read more.

Jaboticaba, a popular Brazilian fruit, has recently garnered scientific interest due to its nutritional properties and high levels of bioactive compounds. However, this fruit is highly perishable due to its high moisture content and physical–chemical structure. Therefore, it is imperative to employ methods for preserving it and explore its potential as a food resource. This study investigates the use of a spray drying method to dehydrate whole jaboticaba fruits. The effects of air temperature (T) ranging from 67.9 to 132.1 °C, air flow rate (AF) from 1.54 to 1.86 m³/min, maltodextrin concentration (M) from 8.9 to 41.1%, and feed flow rate (FF) from 0.36 to 0.84 L/h on the moisture content, drying yield, and bioactive compounds (total phenolic, total flavonoid, citric acid, and ascorbic acid contents) were quantified. The results indicate that spray drying can produce a powder with reduced moisture content levels, a satisfactory drying yield, and high levels of bioactive compounds if performed under specific conditions. An optimization study using desirability analysis shows that having T, AF, M, and FF at 132.1 °C, 1.86 m³/min, 15.0%, and 0.4549 L/h, respectively, is the optimal condition for the studied variables. Spray drying has proven to be a very promising alternative for jaboticaba processing, enabling better applications as a food resource. Full article

(This article belongs to the Topic Innovative and Critical Issues in Natural Resource Management and Exploitation)

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