Resources, Volume 12, Issue 12 (December 2023) – 12 articles

Potato peel is a waste generated in large amounts in the food industry; however, it has been shown that these residues are an important source of antioxidant compounds. The effect of potato peel powder addition (2, 5, and 10%) on the physicochemical, sensory, and antioxidant status of pork patties during refrigerated storage (2 °C/9 days/under dark) was evaluated. Polyphenol content and antioxidant activity of potato peel powder ethanol extract were determined. Pork patties were subjected to proximate chemical composition, physicochemical, and sensory evaluations. Results showed that potato peel ethanol extract at the highest used concentration (500 µg/mL) is an important source of total phenolic (>50 mg gallic acid equivalents/g) and chlorogenic acid compounds (ca. 40 mg chlorogenic acid equivalents/g) and exerts free radical scavenging (>50% of DPPH inhibition) and reducing power activity (<0.5 abs) (p < 0.05). Additionally, potato peel powder incorporation in raw pork patties reduces changes in pH, lipid oxidation, water-holding capacity, cooking loss weight, and color values during storage. Although an effect was observed on texture and sensory values (color and appearance) of raw patties, depending on addition level (p < 0.05), no differences were found in color appearance, odor, flavor, juiciness, fat sensation, texture, and overall acceptability of cooked patties between treatments (p > 0.05). The use of potato peel powder as a natural antioxidant for meat products is recommended. Full article

Analysis of the energy sector from the micro perspective that relates to individual companies is much rarer than a macroeconomic analysis that concerns the power industry as a whole and its impact on the functioning of the economy. However, energy companies directly implement the government’s energy policies and innovation strategies. Thus, this article attempts to answer the question concerning the relationships in three large energy companies operating in Poland (1) between the use of renewable resources for production and the innovative nature of a company, (2) between the use of renewable energy sources and the standing on the stock exchange and profitability. This study used multiple case studies, financial analysis indicators, a time series analysis, and an interdependence analysis. This study covers 2011–2022 and allows consideration of long-term changes in domestic energy policy. Our findings suggest that there is a relationship between a company’s investment activity and the use of renewable energy sources. Unfortunately, the scope of the use of RESs in these companies is small (from ca. 1% to 15%, which demonstrates the low progress of green transformation) and has negative correlations with the investors’ assessment and profitability. In relation to innovation, the ratio of intangible assets to total assets was the highest for Tauron SA, increasing from 1.96% to 5.16%. Its material commitment to innovation is distinguishable from the other two companies. This is also the company with the highest share of RESs in energy production. The second place belongs to Enea SA with its ratio of intangible assets to total assets that increased from 0.72% to 1.69%. The ratio was lowest for PGE SA, increasing from 0.37% to 1.47%. The results and standing of the analyzed energy companies are strongly affected by energy policy amendments, including the improved status of coal and the re-oriented use of RESs (prioritizing solar energy over wind). As a result, these companies, despite the twelve-year period of the implementation of green transformation in the European Union, have achieved little on the path to sustainable energy. Therefore, achieving the goal of a zero-emission economy seems unlikely, since the renewable energy mix is still very slight and not diversified. Changes in energy policy are also not conducive to sectoral and economic innovation. Full article

The active drainage network (ADN), as a dynamic component of a catchment, plays an important role in a catchment’s functioning. Changes in the ADN are the most noticeable during extreme hydro-meteorological events, and they result from, among others, the incorporation of man-origin incisions into the ADN. Knowledge of the parameters of the “real” ADN is a key element in the field of catchment hydrology because the ADN affects the intensity of hydro-, geomorpho-, and biological processes. The goals of this study are to assess (1) the changes in the ADN during extreme hydro-meteorological events (with special attention paid to the human-induced impact on the ADN transformation) and (2) the consequences of the ADN changes on the hydrological response of a catchment and their impact on the flood hazard/risk management processes. The study was performed in a mountain catchment, prone to flash flood occurrences. The ADN was reconstructed with the use of ALS-LiDAR data using GIS tools, and the hydrological response was evaluated by using SCS-CN and GIUH models. The results revealed that the ADN functioning during heavy rainfalls is three to four times denser than the natural-origin river drainage network (RDN) (11.4 km·km⁻² vs. 2.9 km·km⁻²), and the RDN is significantly modified by human-origin elements (e.g., roads, ditches, furrows, etc.—they constitute ca. 1/3 of the ADN). Moreover, significant structural changes in the ADN have occurred, which were confirmed by the Hortonians’ type of analysis. The changes in the ADN have affected the hydrological response of the catchment (predominantly an increase in the peak flow—up to 7%) and the dimensions of the 1% probable flood hazard zone (increase of ca. 5%). It may be concluded that significant changes in the ADN, in the catchment studied, had a moderate impact on the changes in the flood hazard level. The results give a new insight into the flood hazard/risk assessment processes in a small flysch mountain catchment. Full article

Hydrothermal carbonization (HTC) of rice husk was optimized in terms of the adsorption capacity at equilibrium (q_e) and hydrochar mass yield (MY). The studied variables were reaction temperature, residence time, and biomass-to-water ratio by means of response surface methodology. In both cases, reaction temperature resulted the most significant parameter promoting high q_e values at higher temperatures when treating methylene blue (MB) as the target pollutant. Nevertheless, MY was low (~40%) when focusing on a possible industrial application. Hence, maximizing q_e and MY simultaneously by optimization of multiple responses emerges as a promising solution to improve MY values (>60%) with no significant differences regarding the q_e response. Furthermore, additional activation was conducted on optimal hydrochars to further investigate the enhancement of q_e. As a result, no statistical differences between non-modified and activated hydrochars were observed for q_e; however, the pseudo-second-order constant (k₂) seemed to be increased after alkali activation, mainly due to a larger surface area. Non-modified and activated hydrochars were characterized via SEM, FTIR, XRD, and BET, resulting in two significant effects contributing to MB adsorption: increased surface area and functionalized hydrochar surface. Consequently, this work provides valuable insights on subsequent application of this HTC optimization scheme at an industrial scale. Full article

Sustainable mechanisms for efficient and circular metal recycling have yet to be uncovered. In this study, the metal recycling potential of seven metal-resistant bacterial species (Deinococcus radiodurans, Deinococcus aerius, Bacillus coagulans, Pseudomonas putida, Staphylococcus rimosus, Streptomyces xylosus and Acidocella aluminiidurans) was investigated in a multi-step strategy, which comprises bioleaching of industrial waste products and subsequent biosorption/bioaccumulation studies. Each species was subjected to an acidic, multi-metal bioleachate solution and screened for potential experimental implementation. Bacterial growth and metal acquisition were examined using scanning transmission electron microscopy coupled to electron dispersive X-ray spectroscopy (STEM-EDS). Two of the seven screened species, D. aerius and A. aluminiidurans, propagated in a highly acidic and metal-laden environment. Both accumulated iron and copper compounds during cultivation on a multi-metallic bioleachate. Our findings suggest that extremotolerant bacteria should be considered for waste recycling operations due to their inherent polyextremophily. Furthermore, STEM-EDS is a promising tool to investigate microbial–metal interactions in the frames of native industrial waste products. To develop further experimental steps, detailed analyses of adsorption/accumulation mechanisms in D. aerius and A. aluminiidurans are required to design a circular metal recycling procedure. Full article

The aim of this work is to gain a better understanding of the diversity of groundwater resource quality in the Auvergne-Rhône-Alpes region (France) using the national Sise-Eaux database. Three matrices were extracted, which included a hollow matrix (approximately 120,000 observations and 21 variables) and two complete matrices (8078 observations with 13 variables each and 150 observations with 20 variables each, respectively). The mapping of these parameters, the chemical profiles of the water, and the characteristics of the variograms make it possible to estimate the importance of the temporal variance compared with the spatial variance. This distinction led to a typology separating 4 groups of chemical parameters and 2 groups of bacteriological parameters, highlighting the information redundancies linking several parameters. A PCA was used to considerably reduce the size of the hyperspace of the data. The study of the factorial axes combined with their distribution over the study area made it possible to discriminate and identify certain mechanisms for acquiring the physico-chemical and bacteriological characteristics of groundwater, the importance of lithology, the components of faecal contamination, and the role of environmental conditions. A typology of the parameters by hierarchical clustering on the major part of the information makes it possible to reduce the information to that carried by a few representative parameters. This work is a new step in understanding the diversity of groundwater resources in general, with a view to more targeted monitoring based on this diversity. Full article

Non-point source pollution poses a continuous threat to the quality of Great Lakes waters. To abate this problem, the Great Lakes Agricultural Stewardship Initiative (GLASI) was initiated in Ontario, Canada, with the primary aim of reducing phosphorus pollution. Therefore, a case-study analysis of the Wigle Creek watershed, one of the six priority watersheds under the GLASI program, was undertaken to evaluate the effectiveness of various existing and potential future Best Management Practices (BMPs) and to identify BMPs that might aid in mitigating the watershed’s contribution to phosphorus loads reaching Lake Erie. Given the watershed’s very flat topography, hydrological/nutrient modeling proved an extremely challenging exercise. The Soil and Water Assessment Tool (SWAT) model was used in this evaluation. Several digital elevation model (DEM) options were considered to accurately describe the watershed and represent flow conditions. A 30 m resolution DEM, implementing a modified burning in of streams based on ground truthing, was finally employed to develop the SWAT model’s drainage framework. The model was first calibrated for flow, sediment, and phosphorus loads. The calibrated model was used to evaluate the ability of potential BMPs (minimum tillage, no-till, retiring croplands into pasture, retiring croplands into forest, winter wheat cover crop, and vegetative filter strips) to reduce phosphorus loads compared to implemented practice. Converting all croplands into pasture or forest significantly decreased P loads reaching Lake Erie. Comparatively, a winter wheat cover crop had minimal effect on reducing phosphorus loading. Full article

Food resources are essential for the survival and growth of the population. Soil phytopathogenic nematodes cause great damage to agricultural crops, endangering food supplies and resources in general. Different methods have been used to control them. However, this issue still requires a more effective solution. Caenorhabditis elegans (CGC strain wild-type N2) was applied as a model with an Escherichia coli OP50 feeding substrate for nematodes. Our approach was based on the thermodynamically substantiated creation of growth conditions that are unfavorable for nematodes to suppress them irreversibly. The thermodynamic calculations showed that obligate anaerobic conditions, namely the absence of oxygen and a low redox potential (−100 mV and below), were potentially unacceptable for nematodes. Anaerobic conditions were created using both abiogenic (physicochemical) and biological methods. Abiogenic anaerobic conditions were achieved by preventing oxygen access and adding low-potential sodium sulfide (Eh = −250...−200 mV) to the cultivation medium. By applying biological methods, Pleurotus ostreatus Po4 and E. coli O₂ was completely removed and the redox potential was decreased from +100…+200 mV to −100...−200 mV (in particular, due to the synthesis of H₂S). Even the short-term exposure (1–2 days) of nematodes under anaerobic conditions led to their suppression and death. Thus, the short-term creation of anaerobic conditions in the soil may be an effective method to control, e.g., phytopathogenic aerobic nematodes. This research contributes to the development of foundations to preserve agricultural plants and increase crop yield as well as the development of an approach for the environmentally friendly control of phytopathogens. Full article

Given the need to improve bioenergy production processes, it is necessary to focus on low-cost culture media and environmental conditions of radiation and temperature. The Scenedesmus dimorphus species was cultured in eutrophicated lagoon water and Bayfolan 0.3% as culture media under four photoperiods with the objective of evaluating the biomass productivity, bioremediation capacity and influence of illumination on the composition and lipid content. It is concluded that the increase of light hours in the culture with eutrophicated lagoon water produces a decrease in the biomass productivity and COD removal percentage. The highest biomass productivity was obtained in photoperiod F1 (10.5:13.5) hours L:O, 0.053 ± 0.0015 g/L day and a removal of 95.6%. Bayfolan 0.3% with F2 (11.5:12.5) and F3 (12.5:11.5) did not show significant differences in the biomass productivity and COD removal. The increase in light hours in the photoperiod induced an increase of 1.01% and 2.84% of saturated fatty acids and 0.8% and 2.14% of monounsaturated fatty acids, as well as a decrease of 3.85% and 2.88% of polyunsaturated fatty acids in eutrophicated lagoon water and Bayfolan 0.3%, respectively. Full article

Wild mushrooms and truffles (MT) are important resources, which can contribute to the socioeconomic sustainability of forestry ecosystems. However, not all wild MT are edible. Fast, cheap, and reliable methods that distinguish wild MT species (including the deadly ones) can contribute to valuing these important forest resources. Here, we tested if wild MT species, and their edibility, could be distinguished based on their aroma profiles (i.e., smellprints). For that, we combined the use of the electronic nose with classification models (linear discriminant analysis (LDA) and partial least squares discriminant analysis (PLS-DA)) to distinguish between 14 wild MT species (including edible and non-edible species) collected in Portugal. The 14 wild MT species could be accurately distinguished using LDA (93% accuracy), while the edible and non-edible species could be accurately distinguished using both LDA and PLS-DA (97% and 99% accuracy, respectively). Keeping in mind that our methodological design’s feasibility was verified using a small sample, the data show the potential of the combined use of the electronic nose with discriminant analysis to distinguish wild MT species and their edibility based on their aromatic profile. Although a larger dataset will be necessary to develop a quick and reliable identification method, it shows potential to be as accurate as the identification performed by mycologists and molecular biology, yet requiring less technical training, and the analyses are cheaper and faster. Full article

A multi-tracer approach has been implemented in the southwestern part of the Lake Chad Basin to depict the functioning of aquifers in terms of recharge, relationship with surface water bodies, flow paths and contamination. The results are of interest for sustainable water management in the region. The multi-layered structure of the regional aquifer was highlighted with shallower and intermediate to deep flow paths. The shallower aquifer is recharged with rainwater and interconnected with surface water. The groundwater chemistry indicates geogenic influences in addition to a strong anthropogenic fingerprint. The intermediate to deep aquifer shows a longer residence time of groundwater, less connection with the surface and no to only a little anthropogenic influence. Ambient Background Levels (ABLs) and Threshold Values (TVs) show the qualitative status of the groundwater bodies and provide helpful information for water resources protection and the implementation of new directives for efficient and more sustainable groundwater exploitation. Full article

Over the centuries, extensive changes have occurred in the functioning of the hydrosphere. In the case of Poland, the hydrographic network has been significantly transformed, and many of its elements have ceased to exist. The aim of this study was to investigate renaturalised lakes and to determine their original volume, which is a fundamental parameter in the context of stabilising water relationships. Based on archival cartographic materials, the locations of 15 such lakes were determined, with their volume totaling 11.7 million m³. This indicates a significant potential for renaturalised lakes in the context of increasing water resources. In the long term, the methodology adopted in this work may complement water-management efforts aimed at increasing retention and offering new ecosystem services. Such an approach is less invasive to the natural environment and more economically justified compared to new investments in artificial hydrotechnical infrastructure. Full article