Chlorella zofingiensis has been in the center of attention due to its viability of cultivation, capability to yield various products, and applicability in various industrial sectors. Several research ...studies have evaluated this microalga as a bio-factory for carotenoids and lipids production, which are interesting compounds for industrial applications. The microalgae's robustness to various environmental and stress conditions such as light, temperature, salinity, and nutrients' deficiency/excess promotes its importance as a promising source of the mentioned valuable products. Hence, this study intends to review the most prominent contents of C. zofingiensis (i.e., lutein, astaxanthin, exopolysaccharides or EPS, lipids, etc.) and analyze the cultivation and stress conditions which directly influence the quality and quantity of the desired compounds. Upon review, discussions will be conducted to investigate the ability to combine stress factors to increase the contents of interest. Following an investigation over the composition and content induction approaches, several commercial applications of this microalga will be listed and explained, in particular, to obtain valuable products which have been discussed. These applications are chosen to cover multiple sectors, from medical and pharmaceutical, to food and feedstock, biofuel and energy, and wastewater treatment. The broad capability and robustness of C. zofingiensis make it a suitable investment to target more than one sector. Finally, it is discussed and presented a tentative design of a pipeline combining several applications to increase the economic viability of obtaining multiple products.
•Main composition and compounds of interest of C. zofingiensis•Factors targeting to show potential applications of the studied microalga•Cultivation systems and stress factors, individually and grouped•Synergistic interaction between different stress factors•Applications of C. zofingiensis, per each compound of interest
Phycocyanin is a light-blue water-soluble natural pigment with wide application in fields including pharmaceutical, cosmetic and food industry. Arthrospira platensis is considered a natural ...bio-factory for obtaining phycocyanin, and although suitable cultivation conditions can enhance the pigment content, the importance of extraction and purification should not be overlooked, because the chemicals used in those steps can affect the quality of phycocyanin. Further, changes in temperature, or approaches used to extract other protein types from biomass, have been reported to degrade phycocyanin, influencing its final quality, while also contributing to higher energy consumption in the extraction process. Hence, this work compares several approaches for phycocyanin extraction, and analyzed the effects of changes in operating conditions, such as exposure time, application of solvent buffer, and ultrasonication, on the extraction yield, the extracts purity, and the process energy use efficiency. Experimental results point to promising improvements in the extraction yield with high purity of phycocyanin (44.24 mg/g with purity ratio of 0.34), when suitable operating parameters were used (2 h exposure to potassium phosphate buffer with 20 min of ultrasonication).
In either unicellular or multi-cellular form, microalgae are photosynthetic microorganisms, mainly known for being part of the human diet in several world regions. More recently, they have been in ...the spotlight of researchers, not only because of their nutritional value, but also due to their high value-added components. This work reviews five microalgae genera: Dunaliella, Botryococcus, Chlamydomonas, Chlorella and Arthrospira, considered among the most promising for commercial biotechnological applications. The analysis shows that, although the research paradigms are generally shared among species, parameterization changes of culture environment and stress conditions, several applications can be envisaged for the cultivated species, which is discussed in this work. Besides, several applications in which these microalgae are being widely used, or are intended to be used, are analyzed and discussed. The potential applications depend on the type of metabolites found in each microalgae species, which is discussed in this work, giving examples of application and describing methods for their cultivation, harvesting and biomass processing. Thus, in addition to being used in human diet supplementation, microalgae can be used as ingredients for animal feed, medicines, cosmetics pigments, biofuels, bioplastics and biostimulants.
•Five microalgae genera considered most promising for commercial applications.•Type of metabolites found in each microalgae species.•Different methods for cultivation, harvesting and biomass processing.•Microalgae promising commercial applications.
With the development of technology, machine learning (ML), a branch of computer science that aims to turn computers into decision-making agents using the most appropriate algorithms, is also paving ...its way in the modern world. This systematic review arises from the need to understand the impact and report the best practices for applying ML in occupational safety and health. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to provide the best research results. From the 759 identified papers, only 42 were included in the study after applying both exclusion and inclusion criteria. Application is primarily used in accident and risk assessment, and construction and office work are the leaders in applications. The applied methods mainly consist of classification (injuries, accidents, monitoring data), prediction (of hazards), and regression (to find patterns of accidents to prevent them). In conclusion, decision-makers and workers are taking advantage of various artificial intelligence techniques to find solutions in the occupational safety and health environment when experts have access to correct data, either in real-time or recorded datasets. However, it is necessary that in future investigations, limitations of using ML applications in occupational safety and health area be improved and their full potential is achieved.
In recent decades, the pace of industrialization has caused an number of environmental problems. A considerable increase in the global energy demand is one of the most important problems in today’s ...world. In fact, fossil fuels are the main source of energy triggering the release of huge amounts of greenhouse gases into the atmosphere. Many efforts have been made by researchers to come up with different strategies to mitigate the global consequences of greenhouse gas emissions such as global warming. One of these strategies is to reduce the amount of greenhouse gas emited into the atmosphere. This study aims to select the appropriate sites for carbon dioxide underground storage facilities. The selection of the best sites for CO2 underground storage is very important from various perspectives of sustainable development to accelerate the commercialization of such facilities. In this regard, fuzzy-Delphi methodology was used to prioritize the most important criteria in the CO2 storage process. Nineteen sub-criteria were selected in the technical, health, safety and environmental (HSE), economic and social categories. Specialist questionnaires were prepared, considering all relevant scientific and technical aspects, and experts in the field were invited to participate in the survey. The results were analyzed using SPSS 25.0. According to results, Geology and Lithology, Caprock Permeability, Social Acceptance, Depth, Reservoir Permeability, and Porosity were determined as the highest priorities. Based on the results achieved, it can be concluded that technical criteria are of the highest importance in the site selection of underground carbon dioxide site selection facilities.
O declínio da pluviosidade anual, juntamente com o aumento da procura de água para fins agrícolas originou uma nova crise no mundo actual. Neste aspecto, atenções renovadas estão viradas para a ...descoberta de novos recursos hídricos, como efluentes líquidos, devido à sua diminuição consecutiva nas últimas décadas. Embora tenha havido um desenvolvimento de novas metodologias e infra-estruturas de tratamentos de águas residuais, estes não foram largamente aplicados em produtos de irrigação agrícola. Adicionalmente, estudos recentes têm demonstrado que alguns produtos agrícolas têm um risco acrescido de ser contaminados, não podendo ser tratados por infra-estruturas de baixo custo.Olhando para situações do quotidiano, foi demonstrado que a maior parte dos efluentes produzidos podem estar contidos numa categoria de menor poluição, chamada Água Cinzenta. Se se excluir a categoria chamada Água Preta, que inclui dejetos humanos, essencialmente provenientes de sanitas, a maior parte dos efluentes de uma casa é produzida a partir de cozinhas, banheiras, máquina de lavar louça, lavatórios ou mesmo máquina lavar roupa, sendo este conjunto denominado Água Cinzenta. Uma vez que a Água Cinzenta contém menos poluição bacteriana, pode ser considerada um efluente com uma boa relação custo-eficiência para ser tratada e reutilizada.Nesta dissertação, foram estudadas metodologias actuais para tratamento de Água Cinzenta, juntamente com a avaliação de efeitos de irrigação de produtos agrícolas com e sem o tratamento da Água Cinzenta. São ainda apresentados argumentos que recomendam a irrigação de colheitas com Água Cinzenta.
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