Resources

11 pages, 1549 KiB

Open AccessArticle

Biomass Densification to Improve Management Efficiency and to Obtain High Value Products in México

by Rigoberto Rosales-Serna, Artemio Carrillo-Parra, Julio César Ríos-Saucedo, Damián Reyes-Jáquez, Donaji Sierra-Zurita, Saúl Santana-Espinoza, Rafael Jiménez-Ocampo, Pablo Alfredo Domínguez-Martínez and Cynthia Adriana Nava-Berumen

Resources 2024, 13(3), 48; https://doi.org/10.3390/resources13030048 - 20 Mar 2024

Viewed by 2206

Abstract

In México, the utilization of fast-growing plant species for biomass production presents transportation-related issues such as freshness reduction, the transportation of large volumes with minimal weight due to low density, limited storage availability, and logistical challenges. To enhance understanding in this field, the [...] Read more.

In México, the utilization of fast-growing plant species for biomass production presents transportation-related issues such as freshness reduction, the transportation of large volumes with minimal weight due to low density, limited storage availability, and logistical challenges. To enhance understanding in this field, the research aimed to evaluate the densification potential of a variety of organic materials, with a specific emphasis on the biomass derived from eight species of rapidly growing plants, three animal species’ manure, and concentrated feed. After conditioning, 100 g samples underwent particle size analysis and were categorized into seven sizes. Pellets and briquettes (40 g, 10% moisture, 15 MPa pressure, 5 min processing, 80 °C temperature) were produced and evaluated for bulk density (BD) and pellet (PD) and briquette durability (BDU). The predominant particle sizes were 0.850 mm and 0.425 mm. Original biomass bulk density (OBBD) varied notably, with ovine manure (0.50 g cm⁻³) and cattle feed (0.49 g cm⁻³) exhibiting the highest values. Caprine manure (0.83 g cm⁻³) and ovine manure (0.78 g cm⁻³) yielded the densest pellets at 1.76 and 1.84 g cm⁻³, respectively. Apple tree pellets achieved premium quality with the highest hardness (97.9%). Cattle manure (1.25 g cm⁻³) and cattle feed (1.25 g cm⁻³) had the densest briquettes, with notable BBD/OBBD ratios in pine sawdust (4.6) and corn (4.5). Caprine manure and Acacia biomass briquettes showed premium quality with the highest hardness (99.1%), emphasizing densification variations and the need for tailored approaches based on organic material characteristics. Full article

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21 pages, 4652 KiB

Open AccessArticle

The Environmental Oxidation of Acetaminophen in Aqueous Media as an Emerging Pharmaceutical Pollutant Using a Chitosan Waste-Based Magnetite Nanocomposite

by Manasik M. Nour and Maha A. Tony

Resources 2024, 13(3), 47; https://doi.org/10.3390/resources13030047 - 19 Mar 2024

Cited by 1 | Viewed by 1847

Abstract

Clean water is a precious and limited resource that plays a crucial role in supporting life on our planet. However, the industrial sector, especially the pharmaceutical industry, significantly contributes to water consumption, and this can lead to water body pollution. Fenton’s reagent was [...] Read more.

Clean water is a precious and limited resource that plays a crucial role in supporting life on our planet. However, the industrial sector, especially the pharmaceutical industry, significantly contributes to water consumption, and this can lead to water body pollution. Fenton’s reagent was introduced in the current investigation to oxidize acetaminophen as an emerging pollutant in such effluents. Therefore, we employed a straightforward co-precipitation method to fabricate chitosan-coated magnetic iron oxide, which is referred to in this study as Chit@Fe₃O₄. X-ray diffraction spectroscopy (XRD), Fourier transform infrared (FTIR), diffuse reflectance spectra (DRS), scanning electron microscopy (TEM), and transmission electron microscopy (TEM) were utilized to characterize the sample. It is crucial to treat such effluents due to the rapid increase in emerging pollutants. In this study, a photo-Fenton system was introduced as a combination of a Chit@Fe₃O₄ catalyst augmented with hydrogen peroxide under ultraviolet (UV) illumination conditions. The results reveal that only 1 h of irradiance time is efficient in oxidizing acetaminophen molecules. Doses of 20 and 200 mg/L of Chit@Fe₃O₄ and H₂O₂, respectively, and a pH of 2.0 were recorded as the optimal operational conditions that correspondingly oxidize 20 mg/L of acetaminophen to a 95% removal rate. An increase in the reaction temperature results in a decline in the reaction rate, and this, in turn, confirms that the reaction system is exothermic in nature. The sustainability of the catalyst was verified and deemed adequate in treating and oxidizing acetaminophen, even up to the fourth cycle, achieving a 69% removal rate. A kinetic modeling approach is applied to the experimental results, and the kinetic data reveal that the oxidation system conforms to second-order kinetics, with rate constants ranging from 0.0157 to 0.0036 L/mg·min. Furthermore, an analysis of the thermodynamic parameters reveals that the reaction is exothermic and non-spontaneous, predicting an activation energy of 36.35 kJ/mol. Therefore, the proposed system can address the limitations associated with the homogeneous Fenton system. Full article

(This article belongs to the Special Issue Advances in Wastewater Reuse)

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15 pages, 2554 KiB

Open AccessSystematic Review

Circular Economy in Guaiamum and Uçá Crab Waste in Brazil: Potential By-Products—A Systematic Literature Review

by Joel Joaquim de Santana Filho, Pedro Dinis Gaspar, Ana Costa de Souza and Arminda do Paço

Resources 2024, 13(3), 46; https://doi.org/10.3390/resources13030046 - 19 Mar 2024

Viewed by 2470

Abstract

This study aimed to fill a gap in the sustainable management of the reverse supply chain of Guaiamum and Uçá crab waste in Brazil, an endangered species. The study focused on the circular economy, governance, and recent developments, and identified circular economy practices [...] Read more.

This study aimed to fill a gap in the sustainable management of the reverse supply chain of Guaiamum and Uçá crab waste in Brazil, an endangered species. The study focused on the circular economy, governance, and recent developments, and identified circular economy practices in the utilization of solid waste from the fishing and collection of these species in extractive regions, in line with the United Nations (UN) Sustainable Development Goals (SDGs). A systematic literature review was conducted in major scientific databases. The selection of the 20 research publications followed pre-established criteria, including relevance to the SDGs and systematic review methodology. The results highlighted key variables related to the characteristics of by-products and the factors that influence the adoption of circular economy practices, in line with relevant SDGs. The most mentioned by-products include animal feed, organic fertilizer, biofuels, crab shell chitin biocomposite derivatives, as well as Chitosan-based composites for food packaging applications due to their non-toxicity, antimicrobial, and antifungal properties. The study also identified future research opportunities covering education, policy, and management, in line with the UN SDGs. This study emphasizes the importance of the circular economy for solid crab waste in Brazil, a country with 12% of the world’s mangroves, which are essential both as a nursery for crabs and for ocean nutrition. It also analyzes current trends and initiatives in the reverse management of Guaiamum and Uçá crab waste, in the context of Supply Chain and Sustainable Management. Full article

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22 pages, 2734 KiB

Open AccessFeature PaperArticle

Assessment of Environmental Impacts of Thermal Caisson Geothermal Systems

by Pouria Abbasi, Masih Alavy, Pavel Belansky and Marc A. Rosen

Resources 2024, 13(3), 45; https://doi.org/10.3390/resources13030045 - 19 Mar 2024

Viewed by 2009

Abstract

This paper investigates the total environmental impacts of a thermal caisson (TC) system by implementing a life cycle assessment methodology. The total environmental impacts consider the comprehensive effect on the environment across two life cycle stages: manufacturing and operation. A comparison between the [...] Read more.

This paper investigates the total environmental impacts of a thermal caisson (TC) system by implementing a life cycle assessment methodology. The total environmental impacts consider the comprehensive effect on the environment across two life cycle stages: manufacturing and operation. A comparison between the TC results and two different HVAC systems, including air-conditioning/furnace and conventional ground-source heat pump (GSHP) systems, was made by adopting the ReCiPe 2016 methodology. This study reveals that the operation phase is the predominant contributor to environmental impacts across systems, mainly due to its extended duration. Specifically, the operational impacts of GSHPs are substantial, accounting for approximately 87% of total environmental impacts. A TC GSHP system demonstrates a notable environmental advantage, achieving a 79% reduction in total environmental impact when compared to traditional AC/furnace systems. This represents a 21% improvement over conventional GSHP systems. Despite this substantial reduction in total environmental impact, the TC GSHP system shows an almost 5% increase in the resource availability damage category relative to the conventional GSHP, which is attributed to its higher material consumption. These results highlight the TC GSHP system’s superior efficiency in reducing environmental impacts and its potential as a more sustainable alternative in residential heating and cooling applications. Full article

(This article belongs to the Special Issue Exploration and Management of Geothermal Resources)

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18 pages, 5016 KiB

Open AccessArticle

Historical Analysis of the Effects of Drought on Rice and Maize Yields in Southeast Asia

by Teerachai Amnuaylojaroen and Pavinee Chanvichit

Resources 2024, 13(3), 44; https://doi.org/10.3390/resources13030044 - 18 Mar 2024

Cited by 1 | Viewed by 2021

Abstract

This study performs an empirical orthogonal function (EOF) analysis to study the relationship between rice and maize productivities and the different time scales of the Standardized Precipitation Evapotranspiration Index (SPEI), including 1-month, 6-month, and 12-month time scales in Southeast Asia during the years [...] Read more.

This study performs an empirical orthogonal function (EOF) analysis to study the relationship between rice and maize productivities and the different time scales of the Standardized Precipitation Evapotranspiration Index (SPEI), including 1-month, 6-month, and 12-month time scales in Southeast Asia during the years 1970–2019. For the 1-month time scale, the averaged SPEI values are in the range of −1.0 to 1.0, indicating a moderate degree of dryness and humidity. Both 6-month and 12-month time scales suggest that many countries in Southeast Asia are experiencing mostly wet conditions, with SPEI values reaching up to 1.5. The relationship analysis by using EOF was indicated by the first and second principal components (PC1 and PC2) suggesting that drought events exhibit a positive orientation to crop productivity, especially maize in Southeast Asia. The pattern of climate oscillations, such as the El Niño-Southern Oscillation (ENSO), is likely related to crop productivity in Southeast Asia. The findings emphasize the importance of considering temporal climatic patterns in agricultural decision-making, with implications for enhancing regional climate resilience and ensuring sustainable food security in the face of global climate change. Full article

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13 pages, 688 KiB

Open AccessArticle

Bioaccumulation of Cr, Zn, Pb and Cu in Ambrosia artemisiifolia L. and Erigeron canadensis L.

by Volodymyr Laptiev, Samuel Obeng Apori, Michelle Giltrap, Furong Tian and Nataliia Ryzhenko

Resources 2024, 13(3), 43; https://doi.org/10.3390/resources13030043 - 13 Mar 2024

Cited by 3 | Viewed by 1798

Abstract

The city of Dnipro, a prominent industrial hub in Ukraine, is recognized for its particularly its significant industrial development. This study focused on two prevalent plant species, Ambrosia artemisiifolia L. and Erigeron canadensis L., within the vicinity. Sampling was conducted at points located [...] Read more.

The city of Dnipro, a prominent industrial hub in Ukraine, is recognized for its particularly its significant industrial development. This study focused on two prevalent plant species, Ambrosia artemisiifolia L. and Erigeron canadensis L., within the vicinity. Sampling was conducted at points located 12.02 km away from the emission sources associated with battery production and recycling plants in Dnipro. Analysis of heavy metal concentrations such as, Cr, Cu, Pb, and Zn was conducted using atomic emission spectrometry from the soil and plants tissues of Ambrosia artemisiifolia L. and Erigeron canadensis L. The translocation coefficient (TF) was calculated for both plant species. The results revealed that Cu and Zn exhibited the highest bioaccumulation in the examined plants, whereas Pb demonstrated the lowest. The order of metal uptake by both plants was determined as Cu > Zn > Cr > Pb. Significantly higher concentrations of these metals were observed in the two studied plants compared to the soil (Ftheor < Fexp, p < 0.05), suggesting the bioavailability of metals for these plants. The translocation coefficient (TF) represented the ratio of metal concentration in the shoot/the root. The TF value of Erigeron canadensis L. exceeded 1 for four metals. On the other hand, the TF value of Ambrosia artemisiifolia L. surpassed 1 for Cr, Cu, and Zn. Consequently, both species emerge as potential phytoremediators for soils contaminated with these studied metals. Full article

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25 pages, 16874 KiB

Open AccessFeature PaperArticle

The Spatio-Temporal Dynamics of Water Resources (Rainfall and Snow) in the Sierra Nevada Mountain Range (Southern Spain)

by Eulogio Pardo-Igúzquiza, Sergio Martos-Rosillo, Jorge Jódar and Peter A. Dowd

Resources 2024, 13(3), 42; https://doi.org/10.3390/resources13030042 - 12 Mar 2024

Viewed by 1912

Abstract

This paper describes the use of a unique spatio-temporally resolved precipitation and temperature dataset to assess the spatio-temporal dynamics of water resources over a period of almost seven decades across the Sierra Nevada mountain range, which is the most southern Alpine environment in [...] Read more.

This paper describes the use of a unique spatio-temporally resolved precipitation and temperature dataset to assess the spatio-temporal dynamics of water resources over a period of almost seven decades across the Sierra Nevada mountain range, which is the most southern Alpine environment in Europe. The altitude and geographical location of this isolated alpine environment makes it a good detector of climate change. The data were generated by applying geostatistical co-kriging to significant instrumental precipitation and temperature (minimum, maximum and mean) datasets. The correlation between precipitation and altitude was not particularly high and the statistical analysis yielded some surprising results in the form of mean annual precipitation maps and yearly precipitation time series. These results confirm the importance of orographic precipitation in the Sierra Nevada mountain range and show a decrease in mean annual precipitation of 33 mm per decade. Seasonality, however, has remained constant throughout the period of the study. The results show that previous studies have overestimated the altitudinal precipitation gradient in the Sierra Nevada and reveal its complex spatial variability. In addition, the results show a clear correspondence between the mean annual precipitation and the NAO index and, to a much lesser extent, the WeMO index. With respect to temperature, there is a high correlation between minimum temperature and altitude (coefficient of correlation = −0.84) and between maximum temperature and altitude (coefficient of correlation = −0.9). Thus, our spatial temperature maps were very similar to topographic maps, but the temporal trend was complex, with negative (decreasing) and positive (increasing) trends. A dynamic model of snowfall can be obtained by using the degree-day methodology. These results should be considered when checking the local performance of climatological models. Full article

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16 pages, 2697 KiB

Open AccessArticle

Aboveground Biomass and Carbon Storage in Mangrove Forests in Southeastern Mexico

by Carlos Roberto Ávila-Acosta, Marivel Domínguez-Domínguez, César Jesús Vázquez-Navarrete, Rocío Guadalupe Acosta-Pech and Pablo Martínez-Zurimendi

Resources 2024, 13(3), 41; https://doi.org/10.3390/resources13030041 - 12 Mar 2024

Cited by 1 | Viewed by 3287

Abstract

The aboveground contributions of mangroves to global carbon sequestration reinforce the need to estimate biomass in these systems. The objective was to determine the aboveground biomass storage and quantify the carbon and CO₂e content in Rhizophora mangle, Avicennia germinans, and [...] Read more.

The aboveground contributions of mangroves to global carbon sequestration reinforce the need to estimate biomass in these systems. The objective was to determine the aboveground biomass storage and quantify the carbon and CO₂e content in Rhizophora mangle, Avicennia germinans, and Laguncularia racemosa present in southeastern Mexico. Based on the Forest Protocol for Mexico Version 2.0 methodology, published by Climate Action Reserve, 130 circular plots were randomly selected and established in an area of 930 ha of mangrove vegetation, and the aboveground biomass and stored carbon were determined. The mangrove had a density of 3515 ± 428.5 individuals per hectare. The aboveground biomass of the three species was 120.5 Mg ha⁻¹. The biomass of L. racemosa was 99.5 Mg ha⁻¹, which represents 82.6% of the total biomass. The biomass of R. mangle was 20.33 Mg ha⁻¹, and that of A. germinans was 0.32 Mg ha⁻¹. The total carbon retained in the trees was 60.25 Mg C ha⁻¹ and 221.1 Mg CO₂e ha⁻¹. Laguncularia racemosa generated the highest contributions of CO₂e. The area of mangroves accumulated 112,065 Mg of aboveground biomass. The carbon contained in this biomass corresponds to 205,623 Mg CO₂e. This mangrove contributes to mitigating the effects of climate change globally through the reduction in greenhouse gases. Full article

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11 pages, 5967 KiB

Open AccessCommunication

Removal of 2,4-Dichlorophenoxyacetic Acid from Aqueous Solutions Using Al₂O₃/Graphene Oxide Granules Prepared by Spray-Drying Method

by Alexandra Yu. Kurmysheva, Ekaterina Kuznetsova, Marina D. Vedenyapina, Pavel Podrabinnik, Nestor Washington Solís Pinargote, Anton Smirnov and Sergey N. Grigoriev

Resources 2024, 13(3), 40; https://doi.org/10.3390/resources13030040 - 11 Mar 2024

Cited by 3 | Viewed by 1726

Abstract

Within this study, aluminum oxide granules with 0.25%vol. of graphene oxide were prepared by a spray-drying method to make an adsorbent for the 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide removal from aqueous solutions. The obtained adsorbent was studied using infrared spectroscopy, scanning electron microscopy and [...] Read more.

Within this study, aluminum oxide granules with 0.25%vol. of graphene oxide were prepared by a spray-drying method to make an adsorbent for the 2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide removal from aqueous solutions. The obtained adsorbent was studied using infrared spectroscopy, scanning electron microscopy and Raman spectroscopy. The presence of graphene in the spray-dried powder was confirmed. The adsorption removal of 2,4-D using the obtained material was performed at an ambient temperature by varying the process parameters such as pH and adsorption time. The adsorption of 2,4-D was a monolayer chemisorption according to the Langmuir isotherm pattern and a pseudo-second-order kinetic model. The maximum Langmuir adsorption capacity of the monolayer was 35.181 mg/g. The results show that the Al₂O₃-0.25%vol. GO powder obtained by spray drying is suitable for the production of adsorbents for toxic herbicides. Full article

(This article belongs to the Special Issue Advances in Wastewater Reuse)

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17 pages, 15746 KiB

Open AccessArticle

Influence of Geology, Hydrogeology, and Climate on Ground Source Heat Pump Distribution in Slovenia and Selected European Countries

by Simona Adrinek, Mitja Janža and Rao Martand Singh

Resources 2024, 13(3), 39; https://doi.org/10.3390/resources13030039 - 8 Mar 2024

Viewed by 1669

Abstract

Shallow geothermal energy (SGE) is a renewable energy that could contribute to the decarbonatization of the heating and cooling sector. SGE is predominantly harnessed through ground source heat pump (GSHP) systems. The choice of which type of GSHP system depends on various factors. [...] Read more.

Shallow geothermal energy (SGE) is a renewable energy that could contribute to the decarbonatization of the heating and cooling sector. SGE is predominantly harnessed through ground source heat pump (GSHP) systems. The choice of which type of GSHP system depends on various factors. Understanding these factors is crucial for optimizing the efficiency of GSHP systems and fostering their implementation. In this paper, we have analysed the spatial distribution of GSHPs in Slovenia. We identified 1073 groundwater and 1122 ground-coupled heat pump systems with a total heat pump capacity of almost 30 MW. We quantitatively assessed the influence of geological, hydrogeological, and climate conditions on their spatial distribution. Using the χ² test and information value method, we identified hydrogeological conditions as the most influential factor for the GSHP systems’ spatial distribution. We also performed the spatial analysis of geological and hydrogeological data in 22 European countries, including Slovenia. We collected the reported numbers of installed GSHP units in 2020 and were able to distinguish the shares of groundwater and ground-coupled heat pump systems for 12 of these countries. The analysis showed that ground-coupled heat pumps predominate in most countries, even if the natural conditions are favourable for groundwater heat pumps. Full article

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18 pages, 4087 KiB

Open AccessArticle

Are Land Use and Cover Changes and Socioeconomic Factors Associated with the Occurrence of Dengue Fever? A Case Study in Minas Gerais State, Brazil

by Ana Clara Andrade, Luiz Alberto Dolabela Falcão, Magno Augusto Zazá Borges, Marcos Esdras Leite and Mário Marcos do Espírito Santo

Resources 2024, 13(3), 38; https://doi.org/10.3390/resources13030038 - 8 Mar 2024

Viewed by 2116

Abstract

Several studies have already demonstrated the relationship between the loss of natural habitats and the incidence of diseases caused by vectors, such as dengue, which is an acute fever disease that is considered a serious public health problem. The aim of the present [...] Read more.

Several studies have already demonstrated the relationship between the loss of natural habitats and the incidence of diseases caused by vectors, such as dengue, which is an acute fever disease that is considered a serious public health problem. The aim of the present study was to investigate the relationship between the number of dengue cases and land use and cover changes (LUCC) and socioeconomic and climatic factors by municipality, using the state of Minas Gerais as a case study. For this, secondary data obtained from openly available sources were used. Natural vegetation cover data were obtained from the MAPBiomas platform and dengue occurrence data from the Ministry of Health, in addition to eight socioeconomic parameters from the Brazilian Institute for Geography and Statistics and precipitation data from the Brazilian Agricultural Research Corporation (EMBRAPA, Sete Lagoas, Minas Gerais). Between 2015 and 2019, 1,255,731 cases of dengue were recorded throughout the state of Minas Gerais, ranging from 0 to 227 per thousand inhabitants between municipalities. The occurrence of dengue was distributed throughout all regions of Minas Gerais and was associated with LUCC and socioeconomic factors. In general, municipalities with a net loss of natural vegetation, predominantly located in the Cerrado biome, had the highest number of dengue cases in the studied period. Additionally, the occurrence of dengue was associated to three socioeconomic parameters: population density, human development index (both positively), and Gini inequality index (negatively). These results indicate that, contrary to expectations, municipalities with better social conditions had more dengue cases. Our study indicates that natural vegetation is, directly or indirectly, involved in the ecosystem service of dengue control, despite the occurrence of this disease being affected by multiple factors that interact in a complex way. Thus, policies towards reducing deforestation must be complemented by a continuous investment in public health policies and a reduction in social inequalities to efficiently control dengue fever. Full article

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15 pages, 5167 KiB

Open AccessArticle

Utilization of Biomass Waste at Water Treatment

by Isabel Pestana da Paixão Cansado, Pedro Francisco Geraldo, Paulo Alexandre Mira Mourão, José Eduardo Castanheiro, Elisabete Palma Carreiro and Suhas

Resources 2024, 13(3), 37; https://doi.org/10.3390/resources13030037 - 8 Mar 2024

Cited by 2 | Viewed by 1885

Abstract

This work presents some preliminary results on the direct use of untreated biomass from agricultural activities as adsorbents for water treatment. Waste was also used to produce activated carbons (ACs) by chemical activation with KOH. The efficacy of agricultural waste such as stubble, [...] Read more.

This work presents some preliminary results on the direct use of untreated biomass from agricultural activities as adsorbents for water treatment. Waste was also used to produce activated carbons (ACs) by chemical activation with KOH. The efficacy of agricultural waste such as stubble, sawdust from Teak (Tectona Grandis), fibers from Imbondeiro (Adansonia digitata L.), bamboo flowers, and other regional plants were tested on methylene blue (MB) removal from the aqueous phase. Adsorption studies were conducted in a batch system and the influence of kinetics, pH, and temperature was evaluated. The adsorption performance of the natural adsorbents was significantly high concerning MB. In particular, Imbondeiro presented a maximum removal capacity of 188.3 mg per gram. This amount was similar to or even higher than the values obtained on ACs produced by their predecessors at 873 K. The studies were finished by constructing slow filters containing natural adsorbents or ACs. The maximum amounts of MB removed on a continuous flux were lower than those obtained for a diversity of untreated biomass types on a batch system. However, these amounts were comparable to the published results obtained on a diversity of untreated biomasses in batch mode. Full article

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26 pages, 2331 KiB

Open AccessReview

Coastal Acid-Sulfate Soils of Kalimantan, Indonesia, for Food Security: Characteristics, Management, and Future Directions

by Yiyi Sulaeman, Eni Maftuáh, Muhammad Noor, Anna Hairani, Siti Nurzakiah, Mukhlis Mukhlis, Khairil Anwar, Arifin Fahmi, Muhammad Saleh, Izhar Khairullah, Indrastuti Apri Rumanti, Muhammad Alwi, Aidi Noor and Rina Dirgahayu Ningsih

Resources 2024, 13(3), 36; https://doi.org/10.3390/resources13030036 - 6 Mar 2024

Viewed by 2406

Abstract

Coastal acid-sulfate soils are crucial for producing crops and thus, for food security. However, over time, these soil resources experience degradation, leading to higher agro-input, lower yields, and environmental hazards that finally threaten food security. The optimal use of this fragile resource is [...] Read more.

Coastal acid-sulfate soils are crucial for producing crops and thus, for food security. However, over time, these soil resources experience degradation, leading to higher agro-input, lower yields, and environmental hazards that finally threaten food security. The optimal use of this fragile resource is only attained by implementing vigorous integrated water–soil–crop management technologies amid the climate change impact. This study aimed to review the distribution, properties, use, and management of acid-sulfate soils in Kalimantan, Indonesia. Acid-sulfate soils cover about 3.5 Mha of the coastal area in Kalimantan and have high acidity, high-risk iron and aluminum toxicity, and low fertility, requiring precise water management, amelioration and fertilizer application, crop variety selection, and rice cultivation technologies. Lime, biochar, organic fertilizer, compost, ash, and fly ash are ameliorants that raise pH, reduce iron and aluminum toxicity, and improve crop yield. Rice cultivation has developed from traditional to modern but needs re-designing to fit local conditions. Depending on the soil nutrient status, rice cultivation requires 80–200 kg ha⁻¹ of urea, 50–150 kg ha⁻¹ of SP36, 50–150 kg ha⁻¹ of KCl, and 125–400 kg ha⁻¹ of NPK compound fertilizer, but is affected by CH₄ and CO₂ emissions. Good water management impacts the effective implementation of amelioration and fertilizer application technologies. The remaining challenges and future directions for water management, amelioration, fertilizer application, crop varieties, cultivation techniques, land use optimization, climate change adaptation and mitigation, technology adoption and implementation, and resource conservation are outlined. Acid-sulfate soils remain a resource capital that supports food security regionally and nationally in Indonesia. Full article

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38 pages, 4244 KiB

Open AccessReview

A Review on the Recovery and Separation of Gallium and Indium from Waste

by Joanna Kluczka

Resources 2024, 13(3), 35; https://doi.org/10.3390/resources13030035 - 1 Mar 2024

Cited by 2 | Viewed by 4324

Abstract

Gallium and indium are crucial metals in various industries, such as the medical and telecommunication industries. They can find applications as pure metals, alloys and alloy admixtures, oxides, organometallic compounds, and compounds with elements such as nitrogen or arsenic. Recovery of these two [...] Read more.

Gallium and indium are crucial metals in various industries, such as the medical and telecommunication industries. They can find applications as pure metals, alloys and alloy admixtures, oxides, organometallic compounds, and compounds with elements such as nitrogen or arsenic. Recovery of these two metals from waste is an important issue for two main reasons. First, gallium and indium are scattered in the Earth’s crust and their minerals are too rare to serve as a primary source. Second, e-waste contributes to the rapidly growing problem of Earth littering, as its amount increased significantly in recent years. Therefore, it is essential to develop and implement procedures that will enable the recovery of valuable elements from waste and limit the emission of harmful substances into the environment. This paper discusses technological operations and methods that are currently used or may be used to produce pure gallium and indium or their oxides from waste. The first step was described—waste pretreatment, including disassembly and sorting in several stages. Then, mechanical treatment as well as physical, chemical, and physicochemical separations were discussed. The greatest emphasis was placed on the hydrometallurgical methods of gallium and indium recovery, to be more precise on the extraction and various sorption methods following the leaching stage. Methods of obtaining pure metals or metal oxides and their refining processes were also mentioned. Full article

(This article belongs to the Special Issue Editorial Board Members' Collection Series: Resource Conservation, Reuse and Recycling)

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16 pages, 1619 KiB

Open AccessArticle

Reformulation of Persimmon Value-Added Model: Product Downstream Development Strategy for Farmers in East Java, Indonesia

by Ayu Erfiana Asmy, Abdul Rauf, Rahmawaty, Badaruddin and Umrotul Khasanah

Resources 2024, 13(3), 34; https://doi.org/10.3390/resources13030034 - 22 Feb 2024

Viewed by 2364

Abstract

This research aims to reformulate the value-added model of persimmon fruit as an instrument to increase farmers’ income by developing a product downstream strategy. This research was conducted in Malang and Tulungagung in East Java through observation and interviews. Then, we used SWOT [...] Read more.

This research aims to reformulate the value-added model of persimmon fruit as an instrument to increase farmers’ income by developing a product downstream strategy. This research was conducted in Malang and Tulungagung in East Java through observation and interviews. Then, we used SWOT analysis technique (strengths, weaknesses, opportunities, and threats) to identify various factors in reformulating and developing strategies systematically. The results show that farmers must consider product diversification, improved quality and packaging, certification and label, increased nutritional value, marketing and promotion, network and partnership development, training and capacity building, access to capital and financing, research and innovation, and farmer empowerment. Then, in downstream development, it is necessary to carry out strategies in the form of increased production quality, sustainable agricultural practices, processed product development, preparation of partnerships with private parties, effective marketing and promotion, intelligent packaging, product diversification, logistics and distribution optimization, business and financial management, and organic and sustainable certification. This research also identified that persimmon fruit production has great potential, with a large amount land and a high amount of production. In addition, various downstream persimmon products in the form of processed food and beverages can provide significant added value and have the potential to increase farmers’ incomes. Full article

(This article belongs to the Collection Management, Environment, Energy and Sustainability under a Circular Economy)

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