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EISSN : 2079-9276
Published by: MDPI (10.3390)
Total articles ≅ 763
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Latest articles in this journal

Published: 14 October 2021
by MDPI
Abstract:
Since 2017, risk assessments for water intakes in Poland have provided the basis for decisions to establish indirect water protection zones. The preventive, risk-based approach and the related risk minimization measures are required under the provisions of the Drinking Water Directive (DWD) of the European Parliament and of the Council of 16 December 2020 on the quality of water intended for human consumption. This approach is in line with the World Health Organization (WHO) recommendations for water safety plans. The aim of this study was to present a methodology and to carry out a risk assessment of the threats to surface water intakes, which in Poland, should be completed by the end of 2022. Risk assessments were performed for four onshore-type surface water intakes located in south-eastern Poland. The results were presented in aggregate form, which enabled clear presentation and conclusions. It was found that the greatest risks are associated with seasonal changes in water quality (mainly high turbidity and water blooms), unregulated sewage management, the occurrence of floodwater flows and catastrophic events caused by the potential failure of wastewater treatment plants. Based on the results of the risk assessment, the need to establish new, or to adjust the existing, protection zones for the analyzed water intakes was identified.
Published: 13 October 2021
by MDPI
Abstract:
The limits to linear models of production based on material extraction, manufacture, use, and disposal are becoming increasingly apparent across the global economy. The Circular Economy (CE) describes an alternative to this problematic “take-make-waste” linear model that is concerned with resource efficiency and waste minimization. The construction and demolition sector represents an important focus for a CE transition due to its significant environmental impact. The use of thermal insulation to reduce energy demand associated with heating and cooling in buildings is vital for reducing the sector’s high environmental impact; however, there are significant challenges to recycling thermal insulation materials (IM). This study examines these challenges in the context of Switzerland and evaluates the potential for more circular management of expanded polystyrene and stonewool IM. The research provides an original analysis of the Swiss IM value chain in the context of the CE agenda based on a literature review, semi-structured interviews, and a workshop. Research gaps are highlighted based on scientific literature. The roles and agency of actors involved in the Swiss IM value chain are examined. Enablers of and barriers to wider IM recycling as reported by workshop participants are outlined. Interventions for tackling the current challenges faced for the recycling of thermal IM are suggested. Finally, an agenda for future research is proposed. Throughout the discussion, the importance of the involvement, commitment, and collaboration of stakeholders across the entire IM value chain for an effective and expedient transition to a CE is highlighted.
Published: 11 October 2021
by MDPI
Abstract:
Rainwater has been found to be a valuable source of drinking water in Europe, especially in such crisis situations as those caused by contamination of water uptake into water supply systems, large-scale floods or terrorist attacks (e.g., biological weapons). The microbiological quality of water plays a significant role, which is directly related to the potential health risks associated with harvested rainwater (including rainwater stored in the tanks). Microbial contamination is commonly found in rainwater. However, in the literature, detailed results of qualitative and quantitative microbiological assessments are sparse and remain unexplored. Therefore, the aim of this study was to investigate and analyze changes in the microbiological quality of roof-harvested rainwater stored in the tanks, depending on the collection conditions (type of roof surface), storage duration and season. Authors elucidate that conditions such as storage duration, the season in which rainwater is collected, the roof-like surface types and morphology of the catchment area highly affect rainwater quality. This study showed that rainwater harvested from a galvanized steel sheet roof had the best microbial quality, regarding the lowest number of bacteria, while rainwater from a flat roof covered with epoxy resin was the worst. Further, it was detected that rainwater collected in autumn and spring obtained the best microbiological quality. Moreover, a decrease in the number of bacteria was observed in correlation to storage duration. The water became sanitary safe after six weeks of storage at 12 °C. Its use for purposes requiring drinking water quality before six weeks of storage required disinfection.
Published: 8 October 2021
by MDPI
Abstract:
Composting is a sustainable method for recovering nutrients from various organic wastes, including food waste. Every input waste has different nutrient contents, in turn, suggesting that every compost has different fertilizer and/or soil improvement values. The phosphorus (P) concentration and relative distribution of P forms is related to the original organic material. The relative distribution of P forms determines how readily plants can absorb P from the compost-amended soil. The aim of this study was to investigate the content and relative share of P forms in composts made from fish waste, sewage sludge, green waste, and horse manure. Six forms of P (labile; bound to reducible metals; bound to non-reducible metals; bound to easily degradable organic material; and bound to calcium) were determined using sequential extraction method. The results indicated that fish waste compost had relatively high proportion of labile P, suggesting good biological availability. In comparison, sewage sludge compost contained the highest overall P concentration per dry weight unit, while labile P constituted only 6% of summary of P forms. The results indicate that the evaluation of composts as alternative P sources in agriculture should rely on the relative distribution of P forms in the compost in addition to the typically recognized value of the total P.
Published: 30 September 2021
by MDPI
Abstract:
The main aim of this paper is to answer the research question, “Is the Gompertz model suitable for studying the diffusion of the ISO 22000 standard in Europe?” Forecasting models adopting the Gompertz model were developed to estimate to which extent the Food Safety Management Systems (FSMS) based on the ISO 22000 standard are expected to be implemented and certified in the European continent. To provide a forecast for the next few years, data from the diffusion of renowned ISO standards, namely, ISO 9001 and ISO 14001, were extrapolated in order to overcome the shortcoming since data concerning ISO 22000 certification was only available for the period 2007 to 2018. The results provide a cross-sectional portrayal of the European diffusion of ISO 22000 certification and suggest an interval of the estimated number of certificates issued in Europe. This research paper presents the first attempt to empirically analyze the dynamic of diffusion of the European ISO 22000 certification. A more accurate fitting with real results may be expected with further information available in the forthcoming years.
Published: 30 September 2021
by MDPI
Abstract:
Human resources are essential for the mining industry. It is important to understand the requirements of the companies regarding the characteristics of their employees. Job- and career-related web pages of 40 of the world’s top mining companies have been analyzed for the general demands on their employees. These demands are attributed intuitively to seven basic categories (each category includes words with more or less coherent meanings). It is found that the most commonly demanded characteristics are skills, dedication to the work, and personality. Surprisingly, the least attention is paid to social issues. The disclosed expectations are weakly coherent, with the only persistent demand being talent. It also appears that North American and European companies are especially concerned of work dedication, whereas Asian and African companies are primarily concerned of skills. The present study deduces that policy improvements in contemporary mining are necessary—at least, the demands on the employees should be made better in agreement with the actual needs of the mining industry.
Published: 29 September 2021
by MDPI
Abstract:
Four nonlinear regression techniques were explored to model gas oil viscosity on the base of Walther’s empirical equation. With the initial database of 41 primary and secondary vacuum gas oils, four models were developed with a comparable accuracy of viscosity calculation. The Akaike information criterion and Bayesian information criterion selected the least square relative errors (LSRE) model as the best one. The sensitivity analysis with respect to the given data also revealed that the LSRE model is the most stable one with the lowest values of standard deviations of derivatives. Verification of the gas oil viscosity prediction ability was carried out with another set of 43 gas oils showing remarkably better accuracy with the LSRE model. The LSRE was also found to predict better viscosity for the 43 test gas oils relative to the Aboul Seoud and Moharam model and the Kotzakoulakis and George.
Published: 29 September 2021
by MDPI
Abstract:
The bioeconomy can be integral to transforming the current economic system into one with reduced environmental and social impacts of material consumption. This work describes a bio-based multi-layer panel that is based on residual coniferous bark. To ensure that the presented bio-based panel positively contributes to environmental protection while remaining competitive with conventional products and meeting high social standards, the development of the panel is accompanied by a life cycle sustainability assessment. This study performs a comparative LCA and LCC of the developed panel to conventional benchmark panels, as well as a qualitative social life cycle assessment. While the panel performs only economically marginally weaker than the benchmarks, the results are more heterogeneous for the environmental dimension with benefits of the bio-based panel in categories such as climate change, acidification, and ozone formation and detriments in categories including eutrophication. The S-LCA analysis shows that all of the involved companies apply social principles in direct proximity; however, social responsibility along the supply chain could be further promoted. All results need to be viewed with the caveat that the manufacturing processes for the new panel have been implemented, to date, on a pilot scale and further improvements need to be achieved in terms of upscaling and optimisation cycles.
Published: 29 September 2021
by MDPI
Abstract:
The regulation of small rivers and the consequent maintenance works are common in the Central European Lowlands. This article attempts to determine the relationship between the invertebrate fauna (and consequently the biocenosis) of the small lowland river valley and its landforms (morphodynamics) under the conditions of very large and rapid changes caused by river regulation and maintenance. On this basis, an attempt to analyze the response of the ecosystem to rapid transformations associated with engineering works was made. The study covered Kraska, a small river typical for Polish Lowlands, which has been regulated along almost the entire length. The results showed that, in the regulated sections, where the natural forms of the relief were destroyed, there were significantly fewer taxa and significantly smaller numbers of the specimen. Despite the clear negative impact of the regulatory work on the ecosystem, the river in some sections showed the ability to spontaneously restore certain geomorphic features.
Published: 28 September 2021
by MDPI
Abstract:
In southern Africa, several plants are used ethnobotanically as soap substitutes, however, this information resides in different literature sources. The foaming and cleansing properties of such plants are attributed mainly to the presence of saponins, but other compounds such as alkaloids and terpenoids are also implicated. This study aimed to compile a comprehensive list of plants used traditionally as soap substitutes in southern Africa and to assess the chemical properties of selected species. Qualitative phytochemical analysis was done using five solvents (ethanol, methanol, water, chloroform, and acetone) to determine the presence of saponins, alkaloids, and terpenoids in selected soap plants. Quantitative analysis of the saponin content was done employing spectrophotometric tests of methanol extracts. There are thirty-seven (37) known southern African soap plants from twenty-four (24) different families, with the Fabaceae having the highest number of species (eight). Saponin concentrations of nine previously unstudied selected soap plants are reported for the first time in this study, whereby Calodendrum capense had the highest saponin concentrations are at 107.89 ± 4.89 mg/g, followed by Noltea africana (52.65 ± 6.81 mg/g), Crinum bulbispermum (35.43 ± 4.25 mg/g), and Merwilla plumbea (25.59 ± 0.83 mg/g). The knowledge of plant composition gives a better understanding of plant chemistry and possible use of plants medicinally, industrially and as soap substitutes. Furthermore, this allows the verification and the justification of traditional plant use. Soap plants have been used traditionally for many years, the potential to commercialise the use of these plants has been realised with the increase in the use of organic products by conscious consumers hence, the purpose of this investigation can have bearing on future projects and products.
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