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1.
Bioresour Technol ; 374: 128802, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36858122

RESUMEN

The aim of this review was to study why, despite large investments in research and development, algae biodiesel is still not price competitive with fossil fuels. Microalgal production was confirmed to be a critical cost item (84 up to 93 %) for biodiesel regardless of the production technology. Techno-economic assessment revealed the main cost drivers during mass cultivation. It is argued that a breakthrough in the cultivation efficiency of microalgae is identified as a necessary condition for achieving price-competitive microalgal biodiesel. The key bottlenecks were identified as follows: (1) light and O2 concentration management; (2) overnight respiratory loss of oil. It is concluded that most of the research on microalgae biodiesel yields economically over-optimistic presumptions because it has been based on laboratory scale experiments with a low level of interdisciplinary overlap.


Asunto(s)
Biocombustibles , Microalgas , Tecnología , Combustibles Fósiles , Biomasa
2.
Polymers (Basel) ; 14(2)2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-35054673

RESUMEN

Lignin is a natural biopolymer. A vibrant and rapid process in the synthesis of silica nanoparticles by consuming the lignin as a soft template was carefully studied. The extracted biopolymer from coir pith was employed as capping and stabilizing agents to fabricate the silica nanoparticles (nSi). The synthesized silica nanoparticles (nSi) were characterized by ultraviolet-visible (UV-Vis) spectrophotometry, X-ray diffraction analysis (XRD), Scanning Electron Microscope (SEM), Energy-Dispersive X-ray Analysis (EDAX), Dynamic Light Scattering (DLS) and Fourier-Transform Infrared Spectroscopy (FTIR). All the results obtained jointly and independently verified the formation of silica nanoparticles. In addition, EDAX analysis confirmed the high purity of the nSi composed only of Si and O, with no other impurities. XRD spectroscopy showed the characteristic diffraction peaks for nSi and confirmed the formation of an amorphous nature. The average size of nSi obtained is 18 nm. The surface charge and stability of nSi were analyzed by using the dynamic light scattering (DLS) and thus revealed that the nSi samples have a negative charge (-20.3 mV). In addition, the seed germination and the shoot and root formation on Vigna unguiculata were investigated by using the nSi. The results revealed that the application of nSi enhanced the germination in V. unguiculata. However, further research studies must be performed in order to determine the toxic effect of biogenic nSi before mass production and use of agricultural applications.

3.
Environ Sci Pollut Res Int ; 25(18): 18200-18203, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29785596

RESUMEN

Impacts of red beet consumption both on human and animal health are subject of intense research. In particular, products that are not heat-processed contain plethora of bioactive compounds that hold promise against numerous degenerative and aging-associated diseases. However, high level of nitrates (typically more than 2 g NO3- kg-1) whose health effects are perceived with reasoned objections counterbalance these benefits. Following the above, from a certain level, the increased consumption of red beet has contrary impacts, creating a limiting factor not only from the economic point of view but also in terms of beneficial compounds intake. Reduction of NO3- levels (- 35%) has been achieved by soil amendment via increased doses of biochar. The data obtained indicates that the mechanism can be explained as follows. The soil improvement reduces soil density, increases soil temperature, improves water retention, and other prerequisites for increased activity of soil microorganisms. Accelerated metabolism of soil biota turned more nitrogen from fertilizers into organic forms. Hence, less mineral nitrogen is left for red beet intake.


Asunto(s)
Beta vulgaris/química , Carbón Orgánico/química , Fertilizantes , Nitratos/análisis , Contaminantes del Suelo/análisis , Suelo/química , Beta vulgaris/crecimiento & desarrollo , Fertilizantes/análisis
4.
Sci Eng Ethics ; 24(4): 1331-1338, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-28597218

RESUMEN

The trend of emerging biorefineries is to process the harvest as efficiently as possible and without any waste. From the most valuable phytomass, refined medicines, enzymes, dyes and other special reactants are created. Functional foods, food ingredients, oils, alcohol, solvents, plastics, fillers and a wide variety of other chemical products follow. After being treated with nutrient recovery techniques (for fertilizer production), biofuels or soil improvers are produced from the leftovers. Economic optimization algorithms have confirmed that such complex biorefineries can be financially viable only when a high degree of feedstock concentration is included. Because the plant material is extremely voluminous before processing, the farming intensity of special plants increases in the nearest vicinity of agglomerations where the biorefineries are built for logistical reasons. Interdisciplinary analyses revealed that these optimization measures lead to significantly increased pollen levels in neighbouring urban areas and subsequently an increased risk of allergies, respectively costs to the national health system. A new moral dilemma between the shareholder's profit and public interest was uncovered and subjected to disputation.


Asunto(s)
Biocombustibles , Exposición a Riesgos Ambientales/ética , Fertilizantes , Industrias/ética , Plantas , Polen/efectos adversos , Tecnología , Agricultura/economía , Agricultura/ética , Biomasa , Biotecnología , Análisis Costo-Beneficio , Atención a la Salud/economía , Exposición a Riesgos Ambientales/efectos adversos , Ética en los Negocios , Humanos , Hipersensibilidad/etiología , Industrias/economía , Principios Morales , Responsabilidad Social
5.
Sci Eng Ethics ; 24(1): 299-305, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28275935

RESUMEN

The production of renewable energy in agricultural biogas plants is being widely criticized because-among other things-most of the feedstock comes from purpose-grown crops like maize. These activities (generously subsidized in the Czech Republic) generate competitive pressure to other crops that are used for feeding or food production, worsening their affordability. Unique pretreatment technology that allows substitution of the purpose-grown crops by farming residues (such as husk or straw) was built 6 years ago on a commercial basis in Pecín (Czech Republic) under modest funding and without publicity. The design of the concept; financial assessment and moral viewpoint were analyzed based on practical operating data. It showed that the apparatus improves economic, environmental and moral acceptance as well. However, according to the government's view, public funding for this type of processing was shortened, "because waste materials represent a lower cost". The impact of such governance was analyzed as well.


Asunto(s)
Agricultura , Biocombustibles , Conservación de los Recursos Energéticos , Conservación de los Recursos Naturales , Abastecimiento de Alimentos , Residuos Industriales , Tecnología , Agricultura/economía , Agricultura/ética , Costos y Análisis de Costo , Productos Agrícolas , República Checa , Ambiente , Financiación Gubernamental , Abastecimiento de Alimentos/economía , Abastecimiento de Alimentos/ética , Humanos , Principios Morales , Centrales Eléctricas , Tecnología/economía , Tecnología/ética
6.
3 Biotech ; 7(3): 162, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28660451

RESUMEN

Notable progress has been achieved in the past two decades regarding production of different enzymatic mixtures for hydrolysis of the lignocellulose matrix. Nevertheless, the hydrolysing mixtures remain slow and require tempering, which results in high-energy demands and bad financial results. Use of acids or alkali at a very high temperature and pressure accelerates the process more than ten times wherein the energy requirements are approximately equal. However, these elevated reaction conditions might cause the breakdown of complex lignin formula into substances that have the potential to inhibit subsequent fermentation processes. Formation of these breakdown products may be prevented by selecting the optimum process parameters, but their acquisition requires either a large number of expensive analytical techniques or equally large amounts of slow fermentation tests. An inexpensive and time saving alternative that is based on the sensitivity of chosen organisms to these inhibitors was designed and financially assessed. It was confirmed that the method is technically feasible and economically viable with significant potential to reduce the bioethanol production cost.

7.
Sci Eng Ethics ; 23(6): 1667-1672, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-27896607

RESUMEN

From the early days of philosophy, ethics and justice, there is wide consensus that the constancy of the laws establishes the legal system. On the other hand, the rate at which we accumulate knowledge is gaining speed like never before. Due to the recently increased attention of academics to climate change and other environmental issues, a lot of new knowledge has been obtained about carbon management, its role in nature and mechanisms regarding the formation and degradation of organic matter. A multidisciplinary techno-economic assessment of current composting standards and laws that took into account the current state of knowledge about carbon management was carried out as a case study. Economic and environmental damage caused by outdated laws was revealed. In addition, it was found that the introduction of the best composts into the market is permitted, causing additional negative environmental as well as economic impacts.


Asunto(s)
Carbono , Comercio , Compostaje/normas , Ambiente , Fertilizantes/normas , Principios Morales , Suelo/química , Cambio Climático , Comercio/ética , Comercio/legislación & jurisprudencia , Compostaje/economía , Compostaje/ética , Compostaje/legislación & jurisprudencia , Fertilizantes/economía , Humanos , Conocimiento , Responsabilidad Social
8.
Sci Eng Ethics ; 23(4): 1035-1040, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-27896609

RESUMEN

The unethical overuse of antibiotics to seek to achieve a shortening of the treatment period raises the cost of health services and poses a threat to humanity due to the gradual development of antibiotic resistance. Other consequences of our modern passion for antibiotics have appeared. Small concentrations of antibiotic residues in sewage waters slow down the metabolism of anaerobic microorganism thereby reducing the overall performance of the anaerobic fermentation used to detoxify and digest sewage and other collected organic wastes. Reduced biogas yields represents a serious threat to the energy self-sufficiency of some waste-water treatment plants, so it might change them from energy producers into energy consumers. Morally justifiable production of renewable energy from bio-waste is also threatened by antibiotic residues that remain in the bio-waste.


Asunto(s)
Antibacterianos , Uso Excesivo de Medicamentos Recetados/economía , Uso Excesivo de Medicamentos Recetados/ética , Contaminantes Ambientales
9.
Sci Eng Ethics ; 22(2): 581-90, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26026968

RESUMEN

This paper focuses on compost use in overpasses and underpasses for wild animals over roads and other similar linear structures. In this context, good quality of compost may result in faster and more resistant vegetation cover during the year. Inter alia, this can be interpreted also as reduction of damage and saving lives. There are millions of tones of plant residue produced every day worldwide. These represent prospective business for manufacturers of compost additives called "accelerators". The opinions of the sale representatives' with regards to other alternatives of biowaste utilization and their own products were reviewed. The robust analyzes of several "accelerated" composts revealed that the quality was generally low. Only two accelerated composts were somewhat similar in quality to the blank sample that was produced according to the traditional procedure. Overlaps between the interests of decision makers on future soil fertility were weighed against the preferences on short-term profit. Possible causes that allowed the boom of these underperforming products and the possible consequences are also discussed. Conclusions regarding the ethical concerns on how to run businesses with products whose profitability depends on weaknesses in the legal system and customer unawareness are to follow.


Asunto(s)
Agricultura , Comercio/ética , Ética en los Negocios , Reciclaje/métodos , Suelo , Animales , Animales Salvajes , Biomasa , Ecosistema , Humanos , Plantas , Eliminación de Residuos
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