Resources, Volume 12, Issue 10 (October 2023) – 15 articles

Mackerel (Auxis thazard), a tropical dark-fleshed fish, is currently a viable resource for the manufacture of surimi, but the optimal washing procedure for more efficient use of this particular species is required right away. Washing is the most critical stage in surimi production to ensure optimal gelation with odorless and colorless surimi. The goal of this study was to set a simple washing medium to the test for making mackerel surimi. Washing was performed three times with different media. T1 was washed with three cycles of cold carbonated water (CW). T2, T3, and T4 were washed once with cold CW containing 0.3%, 0.6%, or 0.9% NaCl, followed by two cycles of cold water. T5, T6, and T7 were produced for three cycles with CW containing 0.3%, 0.6%, or 0.9% NaCl. For comparison, unwashed mince (U) and conventional surimi washed three times in cold tap water (C) were employed. The maximum yield (62.27%) was obtained by washing with T1. When varying quantities of NaCl were mixed into the first washing medium (T2–T4), the yield decreased with increasing NaCl content (27.24–54.77%). When washing with NaCl for three cycles (T5–T7), the yield was greatly decreased (16.69–35.23%). Conventional surimi washing (C) produced a yield of roughly 40%, which was comparable to T3. Based on the results, treatments that produced lower yields than C were eliminated in order to maximize the use of fish resources and for commercial reasons. The maximum NaCl content in CW can be set at 0.6% only during the first washing cycle (T3). Because of the onset of optimal unfolding as reported by specific biochemical characteristics such as Ca²⁺-ATPase activity (0.2 μmol inorganic phosphate/mg protein/min), reactive sulfhydryl group (3.61 mol/10⁸ g protein), and hydrophobicity (64.02 µg of bromophenol blue bound), T3 washing resulted in surimi with the greatest gel strength (965 g.mm) and water holding capacity (~65%), with fine network structure visualized by scanning electron microscope. It also efficiently removed lipid (~80% reduction), myoglobin (~65% reduction), non-heme iron (~94% reduction), and trichloroacetic acid-soluble peptide (~52% reduction) contents, which improves whiteness (~45% improvement), reduces lipid oxidation (TBARS value < 0.5 mg malondialdehyde equivalent/kg), and decreases the intensity of the gel’s fishy odor (~30% reduction). As a result, washing mackerel surimi (A. thazard) with CW containing 0.6% (w/v) NaCl in the first cycle, followed by two cycles of cold water washing (T3), can be a simple method for increasing gel-forming capability and oxidative stability. The mackerel surimi produced using this washing approach has a higher quality than that produced with regular washing. This straightforward method will enable the sustainable use of dark-fleshed fish for the production of surimi. Full article

Global market developments of wooden pellets have led to an increased attention towards pellet quality. ISO 17829 defines the procedure to assess pellets’ geometrical parameters, which play a key role in pellet overall quality. For instance, pellet length influences the spatial arrangement within the stove brazier, affecting the interaction between combustion air and solid biofuel, thus affecting CO emissions. The ISO 17829 method is time-consuming and affected by the operator’s accuracy. Recent studies have investigated the application of new methods, such as image processing, for monitoring the aforementioned parameter. While also assessing the representativeness of ISO 17829’s method, this paper proposes an alternative measuring tool based on image processing named Pellet Length Detector (PLD). Samples were obtained from Italian pellet suppliers and subjected to a multiple dimensional analysis via PLD and caliper. The PLD’s overall performance led to satisfactory results, with only 10% of the samples having a bias between replicates of >2 mm. Compared to caliper, PLD led to an average bias of 0.5 mm. Moreover, a one-way ANOVA highlighted that increasing the sample size between caliper and PLD leads to a greater statistical similarity of the data obtained for different replicates. Given the prototype status of the device, a further performance upgrade is possible, especially through error modeling. Full article

The emergence of plant-based building materials is supported by several factors, such as shortages, adverse effects, and quality deficits of conventional resources, strict legislative frameworks targeting the realization of Sustainable Development Goals (SDGs), and growing environmental awareness on the individual and stakeholder levels. To support these findings, this paper aimed to assess the relevance of these green materials in the construction industry and highlight the most widespread and thoroughly studied plant-based compounds in the literature, using bibliometric analysis. By evaluating 977 publications from 453 sources, the results show that the total number of relevant papers has increased yearly, while most belonged to the engineering discipline. Most articles were dedicated to one or more of the SDGs, which was confirmed by the more comprehensive representation and elaboration of “green”, “environmental”, and “sustainability” aspects regarding the topics of “materials” and “building” as the most frequent terms. Additionally, a wide range of plant-based building materials are thoroughly evaluated in the literature; these are primarily used to improve conventional materials’ mechanical properties, while many are also tested as substitutes for conventional ones. In conclusion, the green transition in the construction industry is aided by the scientific community by proposing plant-based supplements and alternatives to well-known materials and practices; however, further in-depth studies are needed to verify the applicability of such novelties to gain uniform acceptance and foster the expansion of sustainability initiatives in the sector. Full article

Anaerobic digestion has attracted great interest for use in the management of organic wastes and the production of biomethane. However, this process is facing challenges, such as a high concentration of ammonia nitrogen, which affects the methanogenesis process and, thus, the production of methane. This study investigates the use of biosolid-derived biochar for mitigating ammonia stress and improving methane production during the anaerobic digestion of chicken manure, using both pristine biochar and biochar modified with a potassium hydroxide (KOH) solution. Batch mesophilic anaerobic digestion (37 °C) was carried out over 18 days. When compared to chicken-manure-only controls, a significant increase in methane formation was observed in the digesters amended with biochar and KOH-modified biochar, producing 220 L kg⁻¹ volatile solids (VSs) and 262 L kg⁻¹ VSs of methane, respectively, compared to 139 L kg⁻¹ VSs from the control digesters. The use of biochar and KOH-modified biochar resulted in a significant reduction of 8 days in the lag phase. The total ammonia nitrogen (TAN) concentration was reduced in the digesters with biochar and KOH-modified biochar by 25% and 35.5%, respectively. The quantitative polymerase chain reaction (QPCR) data revealed that the number of 16S rRNA gene copies was around 50,000 and 41,000 times higher in the biochar and KOH-modified biochar digesters, respectively, compared to the control digesters on day 18. The taxonomic profiles indicated that the BC and KOH-BC digesters contained a mixture of methanogenic pathways, including acetoclastic (Methanosaetaceae), hydrogenotrophic (Methanosarcinaceae), and methylation (Methanofastidiosaceae). This mix of pathways suggests a more robust archaeal community and, hence, more efficient methanogenesis. The results show that the addition of biosolids biochar enhances anaerobic digestion, mitigates ammonia stress to methanogens, and significantly increases biogas production. Full article

This work is aimed at illustrating one of the most engaging geoparks in Europe, the Gole della Breggia Geopark. By following its geotrail, the visitors can observe a great deal of features that encompass a wide variety of sedimentary, stratigraphic, tectonic and paleogeographic processes. Its contents are popularized by a comprehensive geotrail that encompasses 23 geostops, enriched with explanatory panels, which enable viewers to gain an overall picture of the complex processes that led to the present-day configuration of the outcrops encountered in the geopark. We have selected five significative outcrops, which we have regarded as fully-fledged geosites, and which encompass the whole 170-million-year interval, from Early Jurassic to Late Miocene times, during which the rocks of the geopark were deposited and deformed. We have performed an assessment of the five geosites, using the most common criteria that can be applied for geosite evaluation. The results of the assessment show that the most valuable geosites are the Lombardian Maiolica, and the Limestone with Pelagic Bivalves. All five geosites, thanks to a QR code added to each figure along the text, can be viewed as virtual geosites (VGs), integrated by 360° videos. Full article

Being key players in providing sustainable energy on a global scale, oil and gas (O&G) companies can contribute to achieving the UN’s Sustainable Development Goals SDG 7 (Affordable and Clean Energy) and SDG 13 (Climate Action). This paper focuses on Russian O&G companies and presents an analysis of their contribution to these SDGs in the context of today’s decarbonization agenda. The study is based on a content analysis of their corporate sustainability reports and has produced three results. First, we analyzed the key strategic goals of Russian O&G companies. Second, we identified the correspondence between the progress towards the SDGs declared in their sustainability reports and the UN’s SDG indicators. Third, we analyzed the contributions of Russian O&G companies to SDGs 7 and 13. As a result of the study, recommendations were formulated to introduce practical tools aimed at increasing the contribution of Russian O&G companies to sustainable development. The article discusses problems in corporate sustainability reporting of Russian O&G companies. The paper also seeks to expand the existing literature on the contribution of the Russian O&G sector to providing sustainable energy and accelerating the energy transition in line with the decarbonization agenda. Full article

Food waste occurs at various stages of the food supply chain, starting from the production stage on farms to processing, distribution, and consumption. It is an important global problem that has social, environmental, ethical, and economic costs. The present work aims to discuss the differences in waste generated from surpluses or leftovers, the monitoring systems of food waste in public food services, and the good practices to reduce food waste. Besides the accessible knowledge about reducing waste, tonnes of food were daily discarded and wasted. To achieve a sustainable food system, food waste must be reduced significantly. Collaborative efforts are necessary to achieve significant reductions in food waste for achieving SDG 12.3 in public food services. Thus, policies that support or enforce larger implementation of best practices are needed. Knowledge about food waste is important to change attitudes and behaviors toward surplus food and leftovers. Some best practices can include promoting awareness campaigns to educate staff about the impact of food waste and the best practices to reduce it, including information on proper storage, portion control, and meal planning; implementing inventory management systems; donating surplus food via collaboration with food banks and charities; optimizing portion sizes, ensuring they are adequate and manageable for customers, reducing the likelihood of leftover food on the plate; allowing customers to order smaller quantities or share a meal; providing packaging to allow customers take their leftovers home for later consumption. The procedures to be adopted by public food services should provide guidance for the selection of products that can be donated. However, specific temperature requirements depending on the food category should be complied with. This paper enlarges the understanding of surpluses and leftovers and the best practices that could be implemented in public food services to minimize food waste. Full article

Municipal wastewater (MWW) provides a promising platform for microalgae cultivation due to its rich content of essential nutrients. Recent research has showcased the multifaceted benefits of microalgae-based wastewater treatment, from the potent depollution capabilities of these organisms to their biomass potential for ecofriendly applications. A significant advantage lies in the ability of these systems to promote environmental sustainability without producing secondary pollutants, aligning with the circular economy model. This approach encompasses various stages, from cultivating microalgae to biomass separation and subsequent valorization. However, challenges arise when scaling these systems to industrial levels. A predominant barrier is the difficulty in maintaining consistent control over all the factors influencing wastewater phytoremediation. This can compromise both biomass survival and the efficiency of pollution removal and valorization. Notably, using native microalgal consortiums from the effluent appears to be a promising strategy. These autochthonous communities often demonstrate superior adaptability and treatment capacity, emphasizing the importance of further exploring their potential to provide effective and economically viable solutions for wastewater treatment. Full article

The functions of community gardens (CGs) are determined by the preferences of their users and external factors such as government restrictions or the situation of the food market. Recent food prices increases and COVID-19 restrictions have shown the importance of CGs as a place for both food self-provisioning (FSP) and relaxation. These have influenced how much the benefits provided by CGs in the form of ecosystem services (ES) are appreciated. This study aims to demonstrate how ES provided by the CG ‘Žížala na Terase’ in Czechia are affected in times of crisis related to the COVID-19 pandemic and to increased food prices, which trigger a demand for greater FSP. The results indicate that the importance of social interaction and educational ES decreased significantly in the COVID-19 scenario. On the contrary, the role of CGs as places for recreation increased. In the FSP scenario, the provisioning ES increased at the expense of recreational ES. The results of the economic assessment further show that the most important monetarily valued ES provided by CGs are cultural ES, followed by provisioning ES. This study demonstrates both the multifunctionality and adaptability of CGs to the current social crises and dynamic urban conditions. Full article

Rewilding attempts to increase biodiversity and restore natural ecosystem processes by reducing human influence. Today, there is growing interest in rewilding urban areas. Rewilding of the Detroit, Michigan, USA and Windsor, Ontario, Canada metropolitan area, and its shared natural resource called the Detroit River, has been delineated through the reintroduction of peregrine falcons and osprey, and a return of other sentinel species like bald eagles, lake sturgeon, lake whitefish, walleye, beaver, and river otter. Rewilding has helped showcase the value and benefits of environmental protection and restoration, ecosystem services, habitat rehabilitation and enhancement, and conservation, including social and economic benefits. Improved ecosystem health and rewilding have become a catalyst for re-establishing a reconnection between urban denizens and natural resources through greenways and water trails. The provision of compelling outdoor experiences in nature, in turn, can help foster a personal attachment to the particular place people call home that can help inspire a stewardship ethic. Full article

Agricultural production activities generate a large amount of waste, most of which is of organic origin from plant remains. These residues could easily be transformed into a resource, specifically, into a substrate for use in soilless cultivation; however, in most cases, they are not used. Therefore, a characterization of local agricultural residues was carried out to determine their use as a substrate for crop cultivation without soil in a protected environment. The selected substrates were Sphagnum peat, coir fiber, and compost, which were managed alone or in mixtures of 50/50, 75/25, or 25/75% v/v ratios. We also included a mixture of virgin mountain soil and earthworm humus (known as INIA mixture) because it is used by local growers. The results showed that the substrates based on coir fiber, peat, and mixtures of both presented suitable characteristics for horticultural crops. On the contrary, compost-based substrates had high pH values and low organic matter contents that could be improved before use. The relationship found between the evaluated parameters of each substrate allowed us to establish that variables, such as the content of organic matter and water at different tensions and particle sizes, can be utilized to make a quick selection of the substrates produced locally, which would lead to the use of waste in a way that is more consistent with sustainable agricultural production and minimal environmental impact, by being used in the production of crops in containers without soil. In addition, these results can be used as an alternative reference in localities where these residues are easily available. Full article

The discourse surrounding sustainability, particularly in the urban environment, has gained considerable momentum in recent years. The concept of a smart city epitomises the integration of innovative technological solutions with community-centred approaches, thereby laying the groundwork for a sustainable lifestyle. One of the crucial components of this integration is the effective and innovative management of waste. The aim of this article was to classify scientific research pertaining to waste management within the context of smart city issues, and to identify emerging directions for future research. A systematic literature review, based on a bibliometric analysis of articles included in the Scopus and Web of Science databases, was conducted for this study. The purpose of such a systematic review is to identify, integrate, and evaluate research on a selected topic, using clearly defined criteria. The research query included: TITLE-ABS-KEY (“smart city” AND (waste OR garbage OR trash OR rubbish)) in the case of Scopus, and TS = (“smart city” AND (waste OR garbage OR trash OR rubbish)) in the case of the Web of Science database. A total of 1768 publication records qualified for the analysis. This study presents an investigation into the current and forthcoming directions of waste management in smart cities, synthesising the latest advancements and methods. The findings outline specific future research directions encompassing technological advancement, special waste challenges, digitisation, energy recovery, transportation, community engagement, policy development, security, novel frameworks, economic and environmental impact assessment, and global implications. These insights reflect a multifaceted approach, advocating a technology-driven perspective that is integral to urban sustainability and quality of life. The study’s findings provide practical avenues for cities to enhance waste management through modern technologies, promoting efficient systems and contributing to sustainable urban living and the circular economy. The insights are vital for policymakers and industry leaders globally, supporting the creation of universal standards and policies, thereby fostering comprehensive waste management systems aligned with global sustainability objectives. Full article

Nitrous oxide (N₂O) is a greenhouse gas contributing to ozone layer depletion and climate change. Wastewater treatment plants (WWTPs) contribute significantly to the global anthropogenic N₂O emissions. The main factors affecting N₂O emissions are the dissolved oxygen concentration (DO), the nitrite accumulation, the rapidly changing process conditions, the substrate composition and COD/N ratio, the pH, and the temperature. Low DO in the nitrification process results in higher N₂O emissions, whereas high aeration rate in the nitration/anammox process results in higher N₂O production. High DO in the denitrification inhibits the N₂O reductase synthesis/activity, leading to N₂O accumulation. High nitrite accumulation in both the nitrification and denitrification processes leads to high N₂O emissions. Transient DO changes and rapid shifts in pH result in high N₂O production. Ammonia shock loads leads to incomplete nitrification, resulting in NO₂⁻ accumulation and N₂O formation. Limiting the biodegradable substrate hinders complete denitrification, leading to high N₂O production. A COD/N ratio above 4 results in 20–30% of the nitrogen load being N₂O emissions. Maximum N₂O production at low pH (pH = 6) was observed during nitrification/denitrification and at high pH (pH = 8) during partial nitrification. High temperature enhances the denitrification kinetics but produces more Ν₂O emissions. Full article

The paper analyzes the results of metal extraction from tailings of ore processing based on traditional approaches. The history of methods of secondary processing of mineral raw materials is described. The technique and features of mechanochemical activation of the leaching process of metal ores and coals are described. The results of laboratory studies of a new mechanochemical technology for metal extraction are presented. A description of the compromise optimal criterion formulated in the model of extraction of metals from tailings with substandard mineral raw materials based on the mathematical planning of the experiment, regression analysis methods and consideration of sanitary standards for the disposal of processing tailings is proposed. Mechanochemical technology results in economic and environmental effects from the utilization of processing tailings and radical strengthening of the mineral resource base of the mining industry. Full article

Understanding the relationship between communities and wetland ecosystems is imperative to facilitate the development of wetland management and conservation strategies that can effectively safeguard wetland health and sustain the flow of ecosystem services. To understand the knowledge, attitude, and perception of communities on wetland ecosystem services, a survey was conducted involving 133 households from 4 villages dependent on 5 wetlands within the Upper Chindwin Basin (UCB), northwestern Myanmar. Most of the respondents extracted wetland resources for subsistence and income. A total of 84% of the households depended on wetland fish for their primary protein consumption, while 70% (n = 94) collected fuelwood from wetlands for subsistence. The survey participants unanimously recognized the benefits of wetland ecosystem services (i.e., provisioning benefits), particularly for fish, food, fiber, fuel, natural medicines, ornamental resources, and minerals. A total of 97% of the participants lacked knowledge of any existing law or regulation that ensures wetland protection in Myanmar. Furthermore, 87% of the respondents concurred that the government has not adequately endeavored to promote awareness of wetland conservation in this remote area due to lack of capacity and resources. This study establishes a baseline for the region and recommends designing and implementing a community-centric wetland action plan. This action plan provides a self-sustaining and cost-effective approach to conserve wetlands and is crucial in enhancing the capacity of dependent communities to participate and eventually lead wetland management of UCB. Full article