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1.
Mediterr J Rheumatol ; 35(1): 199-201, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38736947

RESUMO

In the early 19th century, Auguste François Chomel gathered the knowledge on rheumatism, systematised it, and published it in his majestic work Pathologie Générale. In his treatise, for the first time, rheumatic heart was discussed. Taking into account the opinions of the ancient Greek physicians, he had described the disease as an acute or chronic manifestation of the inflammation of the heart due to rheumatism. His publication rendered rheumatic heart an issue in vogue for his era, a disease being mentioned in all textbooks of the internal pathology.

2.
Sci Rep ; 13(1): 3792, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36882465

RESUMO

Air-cushion (AC) packaging has become widely used worldwide. ACs are air-filled, dual plastic packaging solutions commonly found surrounding and protecting items of value within shipping enclosures during transit. Herein, we report on a laboratory assessment employing ACs as a microalgal photobioreactor (PBR). Such a PBR inherently addresses many of the operational issues typically encountered with open raceway ponds and closed photobioreactors, such as evaporative water loss, external contamination, and predation. Using half-filled ACs, the performance of microalgal species Chlorella vulgaris, Nannochloropsis oculata, and Cyclotella cryptica (diatom) was examined and the ash-free dry cell weight and overall biomass productivity determined to be 2.39 g/L and 298.55 mg/L/day for N. oculata, 0.85 g/L and 141.36 mg/L/day for C. vulgaris, and 0.67 g/L and 96.08 mg/L/day for C. cryptica. Furthermore, maximum lipid productivity of 25.54 mg/L/day AFDCW and carbohydrate productivity of 53.69 mg/L/day AFDCW were achieved by C. cryptica, while maximum protein productivity of 247.42 mg/L/day AFDCW was attained by N. oculata. Data from this work will be useful in determining the applicability and life-cycle profile of repurposed and reused ACs as potential microalgal photobioreactors depending upon the end product of interest, scale utilized, and production costs.


Assuntos
Chlorella vulgaris , Diatomáceas , Microalgas , Fotobiorreatores , Biomassa , Peso Corporal
3.
Eur J Health Econ ; 24(3): 335-347, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35616793

RESUMO

The European continent has one of the longest life expectancies in the world, but still faces a significant challenge to meet the health targets set by the Sustainable Development Goals of the United Nations for 2030. To improve the understanding of the rationale that guides health outcomes in Europe, this study assesses the direction and magnitude effects of the drivers that contribute to explain life expectancy at birth across 30 European countries for the period 2008-2018 at macro-level. For this purpose, an aggregated health production function is used allowing for spatial effects. The results indicate that an increase in the income level, health expenditure, trade openness, education attainment, or urbanisation might lead to an increase in life expectancy at birth, whereas calories intake or quantity of air pollutants have a negative impact on this health indicator. This implies that health policies should look beyond economic factors and focus also on social and environmental drivers. The results also indicate the existence of significant spillover effects, highlighting the need for coordinated European policies that account for the synergies between countries. Finally, a foresight analysis is conducted to obtain projections for 2030 under different socioeconomic pathways. Results reveal significant differences on longevity projections depending on the adoption, or not, of a more sustainable model of human development and provides valuable insight on the need for anticipatory planning measures to make longer life-spans compatible with the maintenance of the welfare state.


Assuntos
Expectativa de Vida , Longevidade , Recém-Nascido , Humanos , Escolaridade , Europa (Continente) , Países em Desenvolvimento , Fatores Socioeconômicos
4.
Maedica (Bucur) ; 18(4): 665-671, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38348074

RESUMO

Introduction: Cilostazol is a selective cyclic inhibitor of the 3-phosphodiesterase type (PDE3) that is recommended to be administered in cases of symptomatic peripheral vascular disease (YEI). It was discovered as a chemical compound in the 1980s, in Takao Nishi laboratory in Japan. Objective: The purpose of the present review was to evaluate the efficacy of cilostazol administration in a YEI with intermittent claudication or moderate to severe lower extremity ischemia. Materials and methods:A systematic review of the literature was carried out where articles were searched in the international database PubMed. The year 2005 was set as a time limit for the publication date of the articles. The following keywords were used: cilostazol, peripheral arterial disease, revascularization and lower limb. A total of 95 articles were found, of which only 10 were selected for the present study. Results:According to the results of the current review, the use of cilostazol increases the ability to walk, improves the quality of life, reduces the rates of re-narrowing of vessels and stents, reduces the likelihood of amputation and is co-administered with other antiplatelet and anticoagulant agents. Conclusion:Cilostazol administration should be a possible treatment option for symptomatic YEI. Further research is necessary to determine its safety after three years.

5.
Bioresour Technol ; 364: 128101, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36241066

RESUMO

Incorporation of microalgae in biorefineries intended to help society reach carbon neutrality is hindered by algal growth inhibition at high temperatures, necessitating the use of costly and carbon-intensive cooling systems. In the present study, a two-prong strategy of random mutagenesis and adaptive laboratory evolution to generate robust thermotolerant strains of Nannochloropsis oculata, was used. The best mutants demonstrated increased productivity at 35 °C, which was 10 °C higher than the optimal temperature of the wild type. In a 2-L photobioreactor at 35 °C, biomass and lipid productivity were 1.43-fold and 2.24-fold higher, respectively, than wild type at 25 °C. Higher pigment and carbohydrate content contributed to the mutants' rapid growth and enhanced photosynthetic efficiency. Metabolomics and lipidomics showed rewiring of the central carbon metabolism and membrane lipid synthesis in thermotolerant strains to ensure cellular homeostasis without compromising productivity. Tagatose and phosphatidylethanolamine upregulation were identified as future genetic targets for further enhancing lipid production.


Assuntos
Microalgas , Estramenópilas , Temperatura , Mutagênese , Fotossíntese , Estramenópilas/genética , Estramenópilas/metabolismo , Microalgas/metabolismo , Biomassa , Lipídeos , Carbono/metabolismo
6.
J Agric Food Chem ; 70(27): 8338-8350, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35767746

RESUMO

Random mutagenesis is an effective strategy for enhancing cellular traits. In this study, we used the mutagen ethyl methanesulfonate to create fast-growing Nannochloropsis oculata mutants. When cultivated in a photobioreactor with a diel cycle, two mutants exhibited 2.2-fold higher carbohydrate productivity and 3.5-4.0-fold higher pigment productivity than the wild type, while one of them also showed 2.5-fold higher lipid productivity. A comprehensive physiological, metabolomic, and lipidomic study showed that the mutants had high levels of glucose-, galactose-, and xylose-based carbohydrates. Their high growth rate was attributed to increased chlorophyll a content, improved nitrogen assimilation, storage, and recycling, and low monogalactosyldiacyl glycerol/digalactosyldiacyl glycerol ratio, which was responsible for higher biomass productivity. The investigation revealed upregulation of lipid precursors, shedding light on high lipid accumulation. The derived algae strains are capable of increasing the biosynthesis of value-added storage molecules without impairing growth, rendering them promising candidates for commercial development in future biorefineries.


Assuntos
Microalgas , Estramenópilas , Biomassa , Carboidratos , Clorofila A , Glicerol , Lipidômica , Lipídeos , Microalgas/genética , Estramenópilas/genética
7.
Sci Total Environ ; 839: 156361, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35640758

RESUMO

High outdoor temperatures significantly inhibit the growth and lipid production of the industrially promising marine microalga Tetraselmis suecica, which is viewed as a potential feedstock for high-value bioproducts and biofuels. To overcome this limitation, T. suecica was subjected to ultraviolet irradiation to generate mutants capable of being productive at higher temperatures. The top two high-lipid mutants UV-25 and UV-31 isolated at 25 °C and 31 °C, respectively, were compared to the wild type (WT) to delineate physiological alterations and shed light on the mutants' increased biomass and lipid productivity. At 25 °C, UV-25 and UV-31 exhibited lipid productivity of 36.12 and 31.33 mg/L day, which were 1.4- and 1.2-fold higher than WT, respectively. This increase in lipid biosynthesis correlated well with increased carotenoid content in UV-25 (2.2-fold) and UV-31 (3.6-fold), indicating an improved capacity to quench reactive oxygen species. At 31 °C, the growth and lipid accumulation of UV-31 remained high, signifying adaptation to higher temperatures. This is attributed to a well-coordinated modulation of the mutant's cellular metabolism through an increase in galactose and phosphatidylglycerol levels, as well as in protein, all of which contributed to its performance at elevated temperatures. The study successfully established a UV mutagenesis strategy for producing superior- performing microalgae strains with industrially desired traits, paving the way for future outdoor cultivation deployment.


Assuntos
Clorófitas , Microalgas , Biocombustíveis , Biomassa , Clorófitas/metabolismo , Lipídeos , Microalgas/metabolismo , Temperatura
8.
Struct Chang Econ Dyn ; 60: 290-301, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35370368

RESUMO

In its revised bioeconomy strategy, the European Union (EU) has extended the scope of activities to include services. Employing an output-based approach, this study quantifies the contribution of bioeconomy services to gross domestic product and employment in the EU Member States over 2008-2017. Moreover, it also identifies the main sectoral sources of employment and growth within bioeconomy services. The choice of Eurostat statistics ensures data harmonisation across countries and continuity for future updates, although important data needs are identified to enhance the representation of bioeconomy services within European statistical frameworks. In 2015-2017, economic growth was stronger in bioeconomy services than in the total EU economy. Bioeconomy services accounted for between 5.0-8.6% and 10.2-16.9% of EU gross domestic product and the EU labour force, respectively, whilst three service sectors account for more than 60% of bioeconomy services employment and value added. Interestingly, in the decade up to 2017, labour productivity in bioeconomy services improved.

9.
Bioresour Technol ; 342: 125890, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34543816

RESUMO

The recycling of unfiltered spent media during cultivation of Chlorella vulgaris was studied using metabolomics in an effort to enhance water and nutrient sustainability and reduce operating costs in algal biorefineries. Cultivation in spent media resulted in reduced biomass and lipid productivity by 14% and 19%, respectively, compared to fresh media. The decrease was related to a detected lower nutrient uptake. Nevertheless, carbohydrate content (28% of dry cell weight) and α-linolenic acid content (27 % of fatty acids) were higher in spent media cultures than in fresh media. Metabolomics analysis of intracellular metabolites revealed downregulation of nitrogen assimilation, tricarboxylic acid cycle, structural lipids, and energy metabolism, but upregulation of stress mitigation and carbohydrate synthesis. No growth was supported by spent media during a second cultivation cycle and was likely due to the identified extracellular accumulation of humic acid and free fatty acids that acted as growth auto-inhibitors.


Assuntos
Chlorella vulgaris , Microalgas , Biomassa , Meios de Cultura , Ácidos Graxos , Lipídeos
10.
Appl Microbiol Biotechnol ; 105(16-17): 6199-6213, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34410439

RESUMO

Propionic acid is an important organic acid with wide industrial applications, especially in the food industry. It is currently produced from petrochemicals via chemical routes. Increasing concerns about greenhouse gas emissions from fossil fuels and a growing consumer preference for bio-based products have led to interest in fermentative production of propionic acid, but it is not yet competitive with chemical production. To improve the economic feasibility and sustainability of bio-propionic acid, fermentation performance in terms of concentration, yield, and productivity must be improved and the cost of raw materials must be reduced. These goals require robust microbial producers and inexpensive renewable feedstocks, so the present review focuses on bacterial producers of propionic acid and promising sources of substrates as carbon sources. Emphasis is placed on assessing the capacity of propionibacteria and the various approaches pursued in an effort to improve their performance through metabolic engineering. A wide range of substrates employed in propionic acid fermentation is analyzed with particular interest in the prospects of inexpensive renewable feedstocks, such as cellulosic biomass and industrial residues, to produce cost-competitive bio-propionic acid. KEY POINTS: • Fermentative propionic acid production emerges as competitor to chemical synthesis. • Various bacteria synthesize propionic acid, but propionibacteria are the best producers. • Biomass substrates hold promise to reduce propionic acid fermentation cost.


Assuntos
Propionatos , Propionibacterium , Fermentação , Engenharia Metabólica
11.
Sci Total Environ ; 800: 149504, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34426316

RESUMO

The inherent metabolic versatility of Chlorella vulgaris that enables it to metabolize both inorganic and organic carbon under various trophic modes of cultivation makes it a promising candidate for industrial applications. To shed light on the metabolic flexibility of this microalga, time resolved proteomic and metabolomic studies were conducted in three distinct trophic modes (autotrophic, heterotrophic, mixotrophic) at two growth stages (end of linear growth at 6 days and during nutrient deprivation at 10 days). Sweet sorghum bagasse (SSB) hydrolysate was supplied to the cultivation medium as a renewable source of organic carbon mainly in the form of glucose. Integrated multi-omics data showed improved nitrogen assimilation, re-allocation, and recycling and increased levels of photosystem II (PS II) proteins indicating effective cellular quenching of excess electrons during mixotrophy. As external addition of organic carbon (glucose) to the cultivation medium decreases the cell's dependence on photosynthesis, an upregulation in the mitochondrial electron transport chain was recorded that led to increased cellular energy generation and hence higher growth rates under mixotrophy. Moreover, upregulation of the lipid-packaging proteins caleosin and 14_3_3 domain-containing protein resulted in maximum expression during mixotrophy suggesting a strong correlation between lipid synthesis, stabilization, and assembly. Overall, cells cultivated under mixotrophy showed better nutrient stress tolerance and redox balancing leading to higher biomass and lipid production. The study offers a panoramic view of the microalga's metabolic flexibility and contributes to a deeper understanding of the altered biochemical pathways that can be exploited to enhance algal productivity and commercial potential.


Assuntos
Chlorella vulgaris , Microalgas , Biomassa , Processos Heterotróficos , Proteômica , Açúcares
13.
Sci Rep ; 11(1): 13768, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215823

RESUMO

The Brazilian government's decision to open the Amazon biome to sugarcane expansion reignited EU concerns regarding the sustainability of Brazil's sugar sector, hindering the ratification of the EU-Mercosur trade agreement. Meanwhile, in the EU, certain conventional biofuels face stricter controls, whilst uncertainty surrounding the commercialisation of more sustainable advanced-biofuels renders bioethanol as a short- to medium-term fix. This paper examines Brazil's land-use changes and associated greenhouse gas emissions arising from an EU driven ethanol import policy and projections for other 13 biocommodities. Results suggest that Brazil's sugarcane could satisfy growing ethanol demand and comply with EU environmental criteria, since almost all sugarcane expansion is expected to occur on long-established pasturelands in the South and Midwest. However, expansion of sugarcane is also driven by competition for viable lands with other relevant commodities, mainly soy and beef. As a result, deforestation trends in the Amazon and Cerrado biomes linked to soy and beef production could jeopardize Brazil's contribution to the Paris agreement with an additional 1 ± 0.3 billion CO2eq tonnes above its First NDC target by 2030. Trade talks with a narrow focus on a single commodity could thus risk unsustainable outcomes, calling for systemic sustainability benchmarks, should the deal be ratified.

14.
Sci Rep ; 11(1): 6779, 2021 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-33762646

RESUMO

Supplementing cultivation media with exogenous carbon sources enhances biomass and lipid production in microalgae. Utilization of renewable organic carbon from agricultural residues can potentially reduce the cost of algae cultivation, while enhancing sustainability. In the present investigation a medium was developed from sweet sorghum bagasse for cultivation of Chlorella under mixotrophic conditions. Using response surface methodology, the optimal values of critical process parameters were determined, namely inoculum cell density (O.D.750) of 0.786, SSB hydrolysate content of the medium 25% v/v, and zero medium salinity, to achieve maximum lipid productivity of 120 mg/L/d. Enhanced biomass (3.44 g/L) and lipid content (40% of dry cell weight) were observed when the alga was cultivated in SSB hydrolysate under mixotrophic conditions compared to heterotrophic and photoautotrophic conditions. A time course investigation revealed distinct physiological responses in terms of cellular growth and biochemical composition of C. vulgaris cultivated in the various trophic modes. The determined carbohydrate and lipid profiles indicate that sugar addition to the cultivation medium boosts neutral lipid synthesis compared to structural lipids, suggesting that carbon flux is channeled towards triacylglycerol synthesis in the cells. Furthermore, the fatty acid profile of lipids extracted from mixotrophically grown cultures contained more saturated and monosaturated fatty acids, which are suitable for biofuel manufacturing. Scale-up studies in a photobioreactor using SSB hydrolysate achieved a biomass concentration of 2.83 g/L consisting of 34% lipids and 26% carbohydrates. These results confirmed that SSB hydrolysate is a promising feedstock for mixotrophic cultivation of Chlorella and synthesis of algal bioproducts and biofuels.


Assuntos
Biomassa , Chlorella vulgaris/fisiologia , Lipídeos/biossíntese , Microalgas/crescimento & desenvolvimento , Fenômenos Fisiológicos Vegetais , Ingestão de Alimentos , Concentração de Íons de Hidrogênio , Fotossíntese , Pigmentos Biológicos/biossíntese , Açúcares/metabolismo
15.
Appl Microbiol Biotechnol ; 104(22): 9619-9629, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33047167

RESUMO

Propionic acid, a widely used food preservative and intermediate in the manufacture of various chemicals, is currently produced from petroleum-based chemicals, raising concerns about its long-term sustainability. A key way to make propionic acid more sustainable is through fermentation of low-cost renewable and inedible sugar sources, such as lignocellulosic biomass. To this end, we utilized the cellulosic hydrolysate of sweet sorghum bagasse (SSB), a residue from a promising biomass source that can be cultivated around the world, for fermentative propionic acid production using Propionibacterium freudenreichii. In serum bottles, SSB hydrolysate supported a higher propionic acid yield than glucose (0.51 vs. 0.44 g/g, respectively), which can be attributed to the presence of additional nutrients in the hydrolysate enhancing propionic acid biosynthesis and the pH buffering capacity of the hydrolysate. Additionally, SSB hydrolysate supported better cell growth kinetics and higher tolerance to product inhibition by P. freudenreichii. The yield was further improved by co-fermenting glycerol, a renewable byproduct of the biodiesel industry, reaching up to 0.59 g/g, whereas volumetric productivity was enhanced by running the fermentation with high cell density inoculum. In the bioreactor, although the yield was slightly lower than in serum bottles (0.45 g/g), higher final concentration and overall productivity of propionic acid were achieved. Compared to glucose (this study) and hydrolysates from other biomass species (literature), use of SSB hydrolysate as a renewable glucose source resulted in comparable or even higher propionic acid yields. KEY POINTS: • Propionic acid yield and cell growth were higher in SSB hydrolysate than glucose. • The yield was enhanced by co-fermenting SSB hydrolysate and glycerol. • The productivity was enhanced under high cell density fermentation conditions. • SSB hydrolysate is equivalent or superior to other reported hydrolysates.


Assuntos
Propionatos , Propionibacterium freudenreichii , Sorghum , Celulose , Fermentação , Propionibacterium
16.
J Clean Prod ; 267: 122147, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32921933

RESUMO

This paper takes three global visions of world development to 2050 and quantifies their implications for sustainable progress employing the metrics of the Sustainable Development Goals (SDGs). The SDG outcomes are structured through the interconnectivities of the three 'wedding cake' layers of 'economy', 'society' and 'biosphere', as posited by the Stockholm Resilience Centre. The key policy contribution is to quantify the resulting SDG synergies and trade-offs, whilst also decomposing and calculating the part-worth of the market drivers which contribute to these outcomes. The paper employs a global economic simulation model that combines rational market behaviour with environmental constraints (MAGNET) and is further extended with an SDG metrics module. A 'non-sustainable' world reveals trade-offs between economy and biosphere SDGs, with population growth of particular concern to a safe planetary operating space in the world's poorest regions. Sustainable visions could reduce natural resource pressures and emissions and meet energy requirements at potentially limited economic cost. Notwithstanding, these futures do not address income inequalities and potentially increase food security concerns for the most vulnerable members of society. Consequently, developed region led international cooperation and in-kind income transfers to developing countries, constitutes a necessary prerequisite to help remedy the SDG trade-offs exhibited within the more sustainable global pathways.

17.
N Biotechnol ; 59: 10-19, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32622862

RESUMO

The EU Bioeconomy Strategy, updated in 2018, in its Action Plan pledges an EU-wide, internationally coherent monitoring system to track economic, environmental and social progress towards a sustainable bioeconomy. This paper presents the approach taken by the European Commission's (EC) Joint Research Centre (JRC) to develop such a system. To accomplish this, we capitalise on (1) the experiences of existing indicator frameworks; (2) stakeholder knowledge and expectations; and (3) national experiences and expertise. This approach is taken to ensure coherence with other bioeconomy-related European monitoring frameworks, the usefulness for decision-making and consistency with national and international initiatives to monitor the bioeconomy. We develop a conceptual framework, based on the definition of a sustainable bioeconomy as stated in the Strategy, for a holistic analysis of the trends in the bioeconomy sectors, following the three pillars of sustainability (economy, society and environment). From this conceptual framework, we derive an implementation framework that aims to highlight the synergies and trade-offs across the five objectives of the Bioeconomy Strategy in a coherent way. The EU Bioeconomy Monitoring System will be publicly available on the web platform of the EC Knowledge Centre for Bioeconomy.


Assuntos
Biotecnologia/economia , Desenvolvimento Econômico , União Europeia
18.
ACS Omega ; 5(25): 15519-15528, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32637827

RESUMO

Cellulose, the most abundant renewable biopolymer, exists in many forms, such as microgranular cellulose (MGCell), sigmacell cellulose (SCell), cellulose fibers (FCell), and α-cellulose (AlfaCell). Several of these cellulose forms were protonated with an amine-containing agent polyethyleneimine (PEI), and the modified celluloses (XCell-PEI+) were studied as catalysts in methanolysis of NaBH4 for hydrogen (H2) generation. It was found that the SCell-PEI+-catalyzed reaction is the fastest one among the modified celluloses with a hydrogen generation rate of 5520 ± 119 mL H2/(g of catalyst × min). The activation energies of MGCell-PEI+, SCell-PEI+, FCell-PEI+, and AlfaCell-PEI+ were determined as +21.7, +23.4, +24.8, and + 21.8 kJ/mol, respectively. Reusability of catalysts was investigated, and regeneration of cellulose based catalysts after the fifth cycle could be readily achieved by HCl treatment to completely recover its activity. Therefore, PEI-modified-protonated cellulose forms constitute sustainable, re-generable, and renewable catalysts for production of H2, an environmentally benign green energy carrier.

19.
World J Microbiol Biotechnol ; 36(3): 39, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32095995

RESUMO

Landfilling of municipal waste, an environmental challenge worldwide, results in the continuous formation of significant amounts of leachate, which poses a severe contamination threat to ground and surface water resources. Landfill leachate (LL) is generated by rainwater percolating through disposed waste materials and must be treated effectively before safe discharge into the environment. LL contains numerous pollutants and toxic substances, such as dissolved organic matter, inorganic chemicals, heavy metals, and anthropogenic organic compounds. Currently, LL treatment is carried out by a combination of physical, chemical, and microbial technologies. Microalgae are now viewed as a promising sustainable addition to the repertoire of technologies for treating LL. Photosynthetic algae have been shown to grow in LL under laboratory conditions, while some species have also been employed in larger-scale LL treatments. Treating leachate with algae can contribute to sustainable waste management at existing landfills by remediating low-quality water for recycling and reuse and generating large amounts of algal biomass for cost-effective manufacturing of biofuels and bioproducts. In this review, we will examine LL composition, traditional leachate treatment technologies, LL toxicity to algae, and the potential of employing algae at LL treatment facilities. Emphasis is placed on how algae can be integrated with existing technologies for biological treatment of LL, turning leachate from an environmental liability to an asset that can produce value-added biofuels and bioproducts for the bioeconomy.


Assuntos
Microalgas/crescimento & desenvolvimento , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Biomassa , Gerenciamento de Resíduos
20.
J Biosci Bioeng ; 129(1): 93-98, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31331795

RESUMO

The present study investigated the effect of light intensity and mixing on microalgae growth in a raceway by comparing the performance of a paddlewheel to a combination of paddlewheel and CO2 spargers in a 20 L raceway. The increase of light intensity was known to be able to increase the microalgal growth rate. Increasing paddlewheel rotation speed from 13 to 30 rpm enhanced C. vulgaris growth by enhancing culture mixing. Simulation results using computational fluid dynamics (CFD) indicated that both the turnaround areas of the raceway and the area opposite the paddlewheel experienced very low flow velocities (dead zones) of less than 0.1 m/min, which could cause cell settling and slow down growth. The simulated CFD velocity distribution in the raceway was validated by actual velocity measurements. The installation of CO2 spargers in the dead zones greatly increased flow velocity. The increase of paddlewheel rotation speed reduced the dead zones and hence increased algal biomass production. By complementing the raceway paddlewheel with spargers providing CO2 at 30 mL/min, we achieved a dry cell weight of 5.2 ± 0.2 g/L, which was about 2.6 times that obtained without CO2 sparging.


Assuntos
Dióxido de Carbono/metabolismo , Chlorella vulgaris/metabolismo , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Biomassa , Reatores Biológicos , Dióxido de Carbono/química , Chlorella vulgaris/química , Chlorella vulgaris/crescimento & desenvolvimento , Chlorella vulgaris/efeitos da radiação , Hidrodinâmica , Luz , Microalgas/química , Microalgas/efeitos da radiação
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