Letteratura scientifica selezionata sul tema "Afbrot"
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Articoli di riviste sul tema "Afbrot"
1
Shelley, Rowland M. "A FOURTH BAHAMIAN RECORD OF THE MILLIPED, AMPHELICTOGON SUBTERRANEUS BAHAMIENSIS CHAMBERLIN, 1918 (POLYDESMIDA: CHELODESMIDAE)". Entomological News 118, n. 3 (maggio 2007): 323–24. http://dx.doi.org/10.3157/0013-872x(2007)118[323:afbrot]2.0.co;2.
Testo completo
2
VILELA, L. M. B., W. V. MACÊDO e E. L. C. AMORIM. "BIOHYDROGEN PRODUCTION FROM CASSAVA WASTEWATER AND DOMESTIC SEWAGE IN AN ANAEROBIC FLUIDIZED BED REACTOR". Latin American Applied Research - An international journal 47, n. 1 (31 gennaio 2017): 29–34. http://dx.doi.org/10.52292/j.laar.2017.293.
Testo completoAbstract (sommario):
This study addresses hydrogen production in two anaerobic fluidized bed reactors (AFBRs) that were fed with cassava wastewater and domestic sewage. The reactors were operated at hydraulic retention times of 4-3 h (AFBR 1) and 4 h (AFBR 2). The maximum hydrogen yields (HY) and the maximum hydrogen production rate (HPR) were, respectively, 0.93 mol H2.mol glucose-1 and 1.69 L.h-1.L-1 (AFBR 1) for the AFBR 1, and 2.03 mol H2.mol glucose-1 and 0.95 L.h-1.L-1 for AFBR 2. The hydrogen content ranged from 2.25 to 23.25% (AFBR 1) and from 7 to 50.75% (AFBR 2). The hydrogen content increased significantly when the amount of domestic sewage decreased, that is, higher concentrations of cassava wastewater in the substrate favors the hydrogen production. Acetic acid was the predominant metabolite that was soluble in both reactors, indicating that the hydrogen production rate and the hydrogen yield made the acetic acid pathway predominant. The association between cassava wastewater and domestic sewage favored biohydrogen production satisfactorily.
3
Minke, R., e U. Rott. "Anaerobic treatment of split flow wastewater and concentrates from the textile processing industry". Water Science and Technology 40, n. 1 (1 luglio 1999): 169–76. http://dx.doi.org/10.2166/wst.1999.0037.
Testo completoAbstract (sommario):
Under anaerobic conditions an almost complete decolorization of many dyes, an efficient COD-removal and a digestion of substances that are refractory under aerobic conditions can be obtained. Therefore anaerobic processes can be used to treat highly loaded split flows and concentrates from the textile processing industry (TPI). Using a large number of biodegradability tests on a bench scale, different types of commercial textile auxiliaries, dyes, real split flow effluents from desizing and dyeing processes and real residual printing pastes were tested in regard to their anaerobic biodegradability. Investigations with anaerobic fixed bed reactors (AFBR) showed that it is possible to treat effluents containing a high organic load from desizing processes and highly coloured effluents from exhaust dyeing processes together resulting in high COD-removal and nearly complete decolorization. With respect to the further aerobic removal of the remaining organic load of the AFBR's effluents it could be seen that the decrease of COD-elimination in AFBR resulting from high portions of effluents from exhaust dyeing processes and short hydraulic retention times is compensated by an increase in aerobic BOD-elimination.
4
Prakash, R., e K. J. Kennedy. "Kinetics of an anaerobic fluidized bed reactor using biolite carrier". Canadian Journal of Civil Engineering 23, n. 6 (1 dicembre 1996): 1305–15. http://dx.doi.org/10.1139/l96-939.
Testo completoAbstract (sommario):
Start-up and steady state operation of anaerobic fluidized bed reactors (AFBRs) with biolite as the inert carrier material was studied. Start-up and concomitant biofilm development of AFBRs was performed using two common start-up techniques, the maximum efficiency profile (MEP) technique and the maximum load profile (MLP) technique. The MEP start-up technique increases the volumetric organic loading rates to the reactor gradually and is tied to the removal efficiency of the process. The MLP start-up technique maintains a moderately high but constant volumetric organic loading rate irrespective of reactor performance. Using sucrose-based wastewater as feed, both start-up techniques led to equally fast biofilm development and start-up times of approximately 5 weeks. However, the MEP technique resulted in more stable controlled reactor operation during the start-up period. The quick start-up confirms the high compatibility of biolite for bio-adhesion and the development of a healthy active biofilm.High concentrations of biofilm biomass achieved in AFBRs (69 g volatile biofilm solids (VBS)/L of expanded bed volume at an organic loading rate of 25 g COD/(Lùd)) allowed the successful treatment of wastewaters at high organic loading rates and organic removal efficiencies. During steady state experiments, organic removal efficiencies over 80% were obtained for organic loading rates as high as 20 g COD/(L∙d). It was found that the dependence of removal efficiency on hydraulic retention time is influenced by substrate concentration. Total biofilm yield was determined to be 0.08 g VBS/g COD removed, demonstrating the low net synthesis of solids in the AFBR. AFBRs had an average solids retention time of 150 days, corresponding to a washout factor of 0.01. Extrinsic kinetics of the AFBRs was determined to be zero order with a maximum specific utilization rate of 0.48 g COD/(g VBS∙d).AFBRs used to treat municipal landfill leachate with a BOD5:COD ratio of 0.86 achieved steady state COD removal efficiencies that ranged from 70% to 87%, depending on the reactor organic loading rate and the concentration of the leachate being treated. During leachate treatment, biofilm biomass gradually became "mineralized" as a result of precipitation of metal sulfides and carbonates. This eventually resulted in a decrease in biofilm microbial activity and the need for higher pumping rates to maintain the same degree of bed expansion. Key words: anaerobic, biological fluidized bed reactor, biolite, landfill leachate, sucrose, modeling, start-up, steady state kinetics.
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Mah, Jae-Hyung, e Jae-Hyuk Yu. "Upstream and Downstream Regulation of Asexual Development in Aspergillus fumigatus". Eukaryotic Cell 5, n. 10 (ottobre 2006): 1585–95. http://dx.doi.org/10.1128/ec.00192-06.
Testo completoAbstract (sommario):
ABSTRACT The opportunistic human pathogen Aspergillus fumigatus produces a large quantity of asexual spores (conidia), which are the primary agent causing invasive aspergillosis in immunocompromised patients. We investigated the mechanisms controlling asexual sporulation (conidiation) in A. fumigatus via examining functions of four key regulators, GpaA (Gα), AfFlbA (RGS), AfFluG, and AfBrlA, previously studied in Aspergillus nidulans. Expression analyses of gpaA, AfflbA, AffluG, AfbrlA, and AfwetA throughout the life cycle of A. fumigatus revealed that, while transcripts of AfflbA and AffluG accumulate constantly, the latter two downstream developmental regulators are specifically expressed during conidiation. Both loss-of-function AfflbA and dominant activating GpaAQ204L mutations resulted in reduced conidiation with increased hyphal proliferation, indicating that GpaA signaling activates vegetative growth while inhibiting conidiation. As GpaA is the primary target of AfFlbA, the dominant interfering GpaAG203R mutation suppressed reduced conidiation caused by loss of AfflbA function. These results corroborate the hypothesis that functions of G proteins and RGSs are conserved in aspergilli. We then examined functions of the two major developmental activators AfFluG and AfBrlA. While deletion of AfbrlA eliminated conidiation completely, null mutation of AffluG did not cause severe alterations in A. fumigatus sporulation in air-exposed culture, implying that, whereas the two aspergilli may have a common key downstream developmental activator, upstream mechanisms activating brlA may be distinct. Finally, both AffluG and AfflbA mutants showed reduced conidiation and delayed expression of AfbrlA in synchronized developmental induction, indicating that these upstream regulators contribute to the proper progression of conidiation.
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Døssing, Kristina Villekjær. "Afbrydelser og forstyrrelse på en akutafdeling". Dansk Tidsskrift for Akutmedicin 2, n. 4 (5 luglio 2019): 71–72. http://dx.doi.org/10.7146/akut.v2i4.113967.
Testo completoAbstract (sommario):
Baggrund
Sygeplejersker på en akutafdeling får flere og flere funktioner. Patienterne skal plejes og behandles, og behandlingen skal koordineres med patient, læge, pårørende, samt nye patienter skal modtages. De mange kontakter stiller store krav til sygeplejerskens kognitive evner, og det kræver, at sygeplejersken hele tiden skal bevare overblikket, så der ikke opstår fejl.
Formål
Formålet med opgaven var at undersøge omfanget af afbrydelser, og hvordan afbrydelser påvirker sygeplejerskens koncentration, og i hvor høj grad afbrydelser påvirker patientsikkerheden.
Metode
Der blev anvendt en kvalitativ metode med feltobservation i egen afdeling på akutafdelingen på Hospitalsenhed Midt i Viborg. Seks sygeplejersker blev observeret i én vagt på seks forskellige dage. Vagterne var af 8 timers varighed og var delt mellem dagvagter og aftenvagter.
En afbrydelse blev defineret, som en personlig eller telefonisk henvendelse på et tidspunkt, hvor sygeplejersken allerede var i gang med en anden opgave, samt patientklokker fra alle stuer på afsnittet, som alarmerede på telefonen. Afbrydelsen kunne både være af mere hastende karakter end den opgave sygeplejersken stod med i forvejen eller mindre hastende karakter.
Resultater
På de seks observationsdage blev sygeplejersken afbrudt i gennemsnit cirka 11 gange i timen, svarende til cirka hvert 5. minut. Cirka 50% af afbrydelserne var patientklokker og cirka 25 % af afbrydelserne var det en anden sygeplejerske, som afbrød.
Sygeplejersken var, trods stort pres på nogle af observationsdage, gode til at holde alle bolde i luften og vende tilbage til de afbrudte opgaver. Det blev vurderet, at patientsikkerheden ikke var i fare, da de sygeplejersker, der blev observeret udviste rummelighed og overskud. Der blev observeret én enkelt episode, hvor sygeplejersken ikke fik udleveret smertestillende medicin rettidigt. Hun kom dog i tanke om det efter cirka 30 minutter, hvorfor det ikke blev vurderet, som en trussel for patientsikkerheden.
Konklusion
Sygeplejersker i dagvagt og aftenvagt i en akutafdeling oplever mange afbrydelser i løbet af vagten. De afbrydelser, der blev observeret i studieperioden, kompromitterede dog ikke patientsikkerheden. Det vurderes alligevel, det er værd at mindske afbrydelserne, så de, der forekommer, er af mere væsentlig karakter.
7
Turan, M., e I. Öztürk. "Longitudinal dispersion and biomass hold-up of anaerobic fluidized bed reactors". Water Science and Technology 34, n. 5-6 (1 settembre 1996): 461–68. http://dx.doi.org/10.2166/wst.1996.0583.
Testo completoAbstract (sommario):
Longitudinal dispersion in fluidized bed reactors was studied using pulse-response techniques for both clean and anaerobic-biofilm coated media. A large number of experimental data on the longitudinal dispersion and biofilm growth in the anaerobic fluidized bed reactors (AFBRs) were investigated. Some correlations applicable to fluidized beds were obtained for both the hydraulic retention time and the biomass concentration versus the ratio Pe/Re. The biomass concentration tends to zero for a critical retention time in AFBRs. The biological growth in the bed causes an increase of Pe number.
8
Budhijanto, Wiratni, Sholahuddin Al Ayyubi e Khalid Abdul Latif. "Evaluasi Rangkaian Anaerobic Fluidized Bed Reactor (AFBR) dan Micro Bubble Generator (MBG) untuk Pengolahan Air Lindi Sampah". Jurnal Teknik Kimia Indonesia 18, n. 1 (14 gennaio 2020): 1. http://dx.doi.org/10.5614/jtki.2019.18.1.1.
Testo completoAbstract (sommario):
Abstrak. Timbulan air lindi adalah masalah serius pada tempat pengolahan sampah akhir (TPA) di Indonesia. Kandungan komponen organik pada sampah Indonesia yang mencapai 70-75% dari total timbulan sampah menyebabkan tingginya produksi lindi sebagai cairan hasil pembusukan. Studi ini bertujuan mengoptimalkan proses pembersihan air lindi dengan rangkaian proses anaerob yang diikuti dengan proses aerob pada skala mini pilot plant. Peruraian anaerobik dijalankan dalam anaerobic fluidized bed reactor (AFBR) dengan media imobilisasi mikroorganisme yang difluidisasi. Tahap selanjutnya adalah proses peruraian secara aerob dengan aerasi menggunakan micro bubble generator (MBG). Pilot plant yang didirikan di tempat pengolahan akhir (TPA) Piyungan di Yogyakarta ini terdiri atas AFBR dengan volume 500 L dan bak aerasi dengan MBG berukuran 500 L. Pengamatan data kualitas air (soluble chemical oxygen demand (sCOD) dan volatile fatty acid (VFA)) pada input/output AFBR dan input/output MBG serta volume biogas yang dihasilkan di AFBR dilakukan secara berkala selama 70 hari start-up di mana reaktor mulai dioperasikan secara kontinu setelah inokulasi secara batch dan 50 hari operasional pada kondisi steady state. Walaupun telah dioperasikan selama lebih dari sebulan, performa AFBR setelah tercapai kondisi steady state belum optimal karena baru mencapai kurang lebih 30% pengurangan kandungan senyawa organik. Performa yang lebih baik teramati pada proses aerob dengan aerasi menggunakan MBG. Proses tersebut berhasil menurunkan sCOD sampai 60%. Studi awal ini menunjukkan bahwa rangkaian AFBR dan MBG berpotensi untuk mengatasi masalah pencemaran air lindi di TPA. Optimalisasi kinerja unit ini terutama ditentukan oleh proses start-up yang dipengaruhi oleh teknik inokulasi. Kata Kunci: fluidisasi, imobilisasi mikrobia, lindi, peruraian aerob, peruraian anaerob, sampah. Abstract. Evaluation of Anaerobic Fluidized Bed Reactor (AFBR) and Micro Bubble Generator (MBG) for Landfill Leachate Treatment. Landfill leachate emission is a very serious problem in Indonesian landfill sites. High organic fraction in Indonesian garbage, which accounts for 70-75% of total municipal solid waste amount, emits high flow rate of leachate as the result of decay process. This study aims to optimize landfill leachate treatment by means of anaerobic process followed by aerobic process. The anaerobic digestion was carried out in AFBR in which microbial immobilization media was fluidized. The next stage was aerobic digestion by applying novel aeration technology using MBG. The pilot plant was installed in Piyungan Landfill Site in Yogyakarta, which consisted of 500 L AFBR and 500 L MBG units. Observation was conducted periodically for 70 days of start-up when the unit was operated continuously after batch inoculation followed by 50 days of steady-state operation. The measurement was taken as soluble chemical oxygen demand (sCOD) and volatile fatty acids (VFA) on the input/output of AFBR and input/output of MBG. The biogas volume production in the AFBR was also measured. AFBR performance was not optimal since even after achieving a steady state condition (for one-month operation), it could only reduce less than 30% organic content. A better performance was observed in the aerobic process where MBG was used for the aeration. It could reduce 60% of sCOD. This preliminary study showed that the coupling of AFBR and MBG units is potential for landfill leachate treatment. Optimization of this unit depended on the inoculation technique during the start-up period. Keywords: aerobic digestion, anaerobic digestion, fluidization, landfill leachate, microbial immobilization, municipal solid waste. Graphical Abstract
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Rajamohan, Rajaram, Sundarajulu Kothai Nayaki e Meenakshisundaram Swaminathan. "Spectrofluorimetric Study on Inclusion Complexation of 2-Amino-6-fluorobenzothiazole with β-Cyclodextrin". Collection of Czechoslovak Chemical Communications 73, n. 2 (2008): 147–60. http://dx.doi.org/10.1135/cccc20080147.
Testo completoAbstract (sommario):
The interaction between 2-amino-6-fluorobenzothiazole (AFBT) and β-cyclodextrin (β-CDx) has been investigated in aqueous solution and in the solid state. The stoichiometry and binding constant of the complex between AFBT and β-CDx in solution were determined by steady-state and time-resolved fluorescence spectroscopy. The FT-IR spectral data and SEM images of the solid complex confirmed the formation of inclusion complex. The proton transfer behaviour of AFBT has been investigated in aqueous and β-CDx solutions.
10
Prasetyo, Elli. "Evaluasi Hydraulic Retention Time (Hrt) Terhadap Removal Chemical Demand (Cod) Dalam Pengolahan Air Lindi Menggunakan Aerobic Fluidized Bed Reactor (AFBR)". Jurnal Migasian 2, n. 2 (30 dicembre 2018): 28. http://dx.doi.org/10.36601/jurnal-migasian.v2i2.28.
Testo completoAbstract (sommario):
Sampah merupakan masalah utama disetiap kota besar di indonesia. Tumpukan sampah menghasilkan air lindi dengan kandungan organik yang tinggi. Beban organik yang tinggi dan meningkatnya laju alir lindi memerlukan kolam aerasi yang luas untuk mengolah lindi. Salah satu metode pengolahan air lindi yang tepat dan efisien dengan menggunakan proses anaerobik. Anaerobic Fludized Bed Reaktor (AFBR) merupakan salah satu reactor anaerobic dengan efisiensi tinggi. Zeolit digunakan sebagai media imobilisasi bakteri untuk meningkatkan efisiensi pengolahan secara anaerobic pada reactor AFBR. Penyesuaian model kinetika dilakukan pada tahap awal menggunakan data reactor fase batch untuk diaplikasikan pada AFBR fase continyu. Model kinetika untuk mengevaluasi pengaruh Hydraulic Retention Time (HRT) terhadap removal Chemical Oxygen Demand (COD) AFBR dengan zeolit sebagai media imobilisasi. Eksperimen dilakukan dalam tiga fase, yaitu fase batch, fase start-up, dan fase steady state. Fase batch bertujuan untuk menentukan konstanta model kinetika. Fase start-up bertujuan untuk memverifikasi konstanta model yang ditentukan dengan data batch pada AFBR saat masa start up. Fase steady state bertujuan untuk mengevaluasi pengaruh HRT selama reactor beroperasi. Reaktor AFBR mencapai kondisi steady state tercepat pada HRT 10 dengan removal COD 73,40%. Hal ini membuktikan bahwa mikroorganisme tidak mengalami washout bahkan pada laju beban organik yang lebih tinggi sehingga mikroorganisme dapat menstabilkan populasinya. Data menunjukkan bahwa sCOD effluen (SCODeff) lindi TPA Piyungan mencapai nilai terendah pada kisaran 2.000 – 2.500 mg/L, Produksi biogas mengikuti fluktuasi nilai sCODeff. Pada kondisi steady state, nilai ini tidak dipengaruhi oleh HRT.
Tesi sul tema "Afbrot"
1
Padron, Harold. "Combined anaerobic/aerobic treatment for municipal wastewater". ScholarWorks@UNO, 2004. http://louisdl.louislibraries.org/u?/NOD,110.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of New Orleans, 2004.Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in the Environmental Engineering Program."--Thesis t.p. Vita. Includes bibliographical references.
2
Ferreira, Tiago Borges. "Produção de hidrogênio e metabólitos solúveis a partir de subprodutos da indústria sucroalcooleira em reator anaeróbio de leito fluidificado termofílico". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-27032017-164955/.
Testo completoAbstract (sommario):
A indústria sucroalcooleira nacional, fruto da política de autonomia energética da década de 70, busca no aumento de portifólio produtivo a melhora da eficiência produtiva e energética. A produção de hidrogênio e metabólitos dissolvidos por processo biológico é uma linha de pesquisa relativamente recente, porém, que pode representar uma alternativa para esse setor, maximizando a produção de energia e ampliando a produção de compostos de alto valor agregado. Partindo destes preceitos, o objetivo deste trabalho foi avaliar a produção de hidrogênio e ácidos orgânicos por meio da fermentação escura a partir de compostos da indústria sucroalcooleira; sacarose (RS), caldo (RC), melaço (RM) e vinhaça (RV) a 5.000 mg DQO L-1, em reatores anaeróbios de leito fluidificado termofílicos (55°C), submetidos a tempos de detenção hidráulica (TDH) de 8, 6, 4, 2 e 1h. O inóculo utilizado foi obtido a partir de lodo de reator de manta de lodo metanogênico empregado na biodigestão de vinhaça de cana-de-açúcar em faixa termofílica de temperatura (55°C). As produtividades volumétricas de hidrogênio (PVH) mais elevadas foram obtidas quando em operação em TDH de 1h, sendo 194,9; 501,4; 303,4 e 40,7 mL H2 h-1 L-1 para RS, RC, RM e RV, respectivamente. Os melhores rendimentos de hidrogênio (HY) foram logrados em distintos TDH; 1,97; 3,01; 2,5 e 0,65 mol H2 mol- 1 sacarose quando RS, RC, RM e RV foram operados em 4, 6, 2 e 1h, respectivamente. Na fase de maior PVH, os metabólitos dissolvidos predominantes resumiram-se a ácido lático, ácido acético, ácido butírico, ácido propiônico, ácido málico e etanol, condicionados ao substrato empregado em cada reator. Assim, evidenciou-se a possibilidade de produção de hidrogênio, ácidos orgânicos e etanol por meio da fermentação escura aplicada aos substratos desta indústria, confirmando que a produção de energia e produtos de elevado valor agregado pode ser uma aplicação alternativa para seus compostos.The national sugarcane industry, coming from the energy policy autonomy of the 70s, seeks increase its portfolio productive improvement of productive and energy efficiency. Hydrogen and dissolved metabolites production by biological process is a relatively recent research line, however it, may represent an alternative for this sector, maximizing energy production and increasing the value-added compounds production. Based on these principles, the aim of this study was to evaluate the hydrogen and dissolved metabolites production by means of the dark fermentation from compounds of the sugarcane industry; sucrose (RS), sugarcane juice (RC), molasses (RM) and vinasse (RV) with 5,000 mg COD L- 1in thermophilic anaerobic fluidized bed reactor (55°C) submitted to hydraulic retention time (HRT) of 8, 6, 4, 2, and 1h. The inoculum was obtained from methanogenic upflow anaerobic sludge blanket reactor employed to digestion of sugarcane stillage in thermophilic temperature range (55°C). The highest hydrogen production rates (HPR) of these reactors were obtained when operating in HRT 1h, which were 194.9, 501.4, 303.4, and 40.7 mL H2 h-1 L-1 to RS, RC , RM, and RV respectively. The best hydrogen yield (HY) were duped in differents HRT; 1.97, 3.01, 0.65, and 2.5 mol H2 mol-1 sacarose when RS, RC , RM, and RV were operated in 4, 6, 2, and 1h , respectively. When were produced the biggest HPR, the predominant dissolved metabolites were lactic acid, acetic acid, butyric acid, propionic acid, malic acid and ethanol, dependent on the substrate used in each reactor. Therefore, evidence of the possibility of hydrogen, organic acids and ethanol production by dark fermentation applied to substrates that industry, confirming that the production of energy and high value-added products may be an alternative application for their compounds.
3
Simões, Andreza Nataline. "Processamento do glicerol bruto em reatores anaeróbios de leito fluidificado, acidogênico e metanogênico, em temperatura mesofílica". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-12062017-095758/.
Testo completoAbstract (sommario):
A utilização de combustíveis renováveis tem se destacado nos últimos anos, principalmente devido aos impactos ambientais gerados pelo uso de combustíveis fósseis e escassez dos mesmos. Dentre os combustíveis renováveis destaca-se o biodiesel, cujo processo produtivo apresenta como principal subproduto o glicerol bruto, que tem instigado nos últimos anos intensas discussões sobre a problemática de sua destinação e disposição final. Apesar de ser utilizado na indústria química, o seu teor de impurezas limita o seu processamento industrial. Buscando agregar valor a esse resíduo bruto e contribuir para a produção de bioenergia, este trabalho teve por intuito avaliar a produção dos biocombustíveis hidrogênio e metano, assim como de intermediários químicos a partir de glicerol bruto como substrato em reatores anaeróbios de leito fluidificado (RALF), mesofílicos (30°C), utilizando inóculo de cultura mista. O RALF-H2, com o objetivo de produzir hidrogênio e metabólitos solúveis, foi submetido à concentração de 10 g.L-1 de glicerol e variação do tempo de detenção hidráulica (TDH) de 8, 6, 4, 2, 1 e 0,5 h. Já o RALF-CH4, com intuito de produzir metano, operou sob TDH fixo de 24 h, submetido à variação da concentração de glicerol de 1, 2, 3, 4, 5 e 7 g.L-1, e portanto, da taxa de carregamento orgânico (TCO) de 1, 2, 3, 4, 5 e 7 kgDQO.m-3.d-1, respectivamente. No RALF-H2, os valores máximos de conteúdo de hidrogênio no biogás (69,2 %), produtividade volumétrica de hidrogênio (1,90 L.h-1.L-1) e rendimento de hidrogênio (0,28 molH2.mol-1glicerolconsumido) foram verificados no TDH de 0,5 h. O 1,3-propanodiol se destacou entre os metabólitos produzidos, com rendimento máximo de 0,57 mol1,3-PDO.mol-1glicerolconsumido, alcançado no TDH de 8 h. No RALF-CH4, o máximo conteúdo de metano no biogás (83,0%) foi verificado na TCO de 1 kgDQO.m-3.d-1, a maior produtividade volumétrica de metano (2,26 L.d-1.L-1) na TCO de 5 kgDQO.m-3.d-1 e o máximo rendimento (0,19 m3H4.kg-1DQOaplicada ou 0,77 molCH4.mol-1glicerolconsumido) na TCO de 4 kgDQO.m-3.d-1. Portanto, os resultados evidenciaram a possibilidade de produção de biocombustíveis e metabólitos de valor agregado utilizando glicerol bruto como substrato no processo da digestão anaeróbia.The use of renewable fuels has been highlighted in recent years, mainly due to the environmental impacts generated by the use of fossil fuels and their scarcity. Among the renewable fuels highlights the biodiesel, whose production process displays as the main byproduct crude glycerol, which has instigated in recent years, intense debates about a problem of its destination and final disposal. Although it is used in the chemical industry, its impurities content limits its industrial processing. In order to add value to this crude residue and to contribute to the production of bioenergy, this work aimed to evaluate the production of biofuels hydrogen and methane, as well as chemical intermediates from crude glycerol as substrate in anaerobic fluidized bed reactors (AFBR), mesophilic (30°C), using mixed culture inoculum. The AFBR-H2, with the objective of producing hydrogen and soluble metabolites, was submitted to a concentration of 10 g.L-1 of glycerol and a variation of the hydraulic retention time (HRT) of 8, 6, 4, 2, 1 and 0.5 h. The AFBR-CH4, with the intention of producing methane, operated under fixed HRT of 24 h, subjected to the variation of the glycerol concentration of 1, 2, 3, 4, 5 and 7 g.L-1 and, therefore, of the organic loading rate (OLR) of 1, 2, 3, 4, 5 and 7 kgCOD.m-3d-1, respectively. In the AFBR-H2, the maximum values of hydrogen content in the biogas (69.2%), hydrogen volumetric productivity (1.90 L.h-1.L-1) and hydrogen yield (0.28 molH2.mol-1glycerolconsumed) were verified in the HRT of 0.5 h. The 1,3-propanediol was highlighted among the metabolites produced, with a maximum yield of 0.57 mol1,3-PDO.mol-1glycerolconsumed, reached in the TDH of 8 h. In the AFBR-CH4, the higher methane content in the biogas (83.0%) was detected in the OLR of 1 kgCOD.m-3.d-1, a higher volumetric productivity of methane (2.26 L.d-1.L-1) in the OLR of 5 kgCOD.m-3.d-1 and the maximum yield (0.19 m3CH4.kg-1CODapplied or 0.77 molCH4.mol-1glycerolconsumed) in the OLR of 4 kgCOD.m-3d-1. Therefore, the results evidenced the possibility of producing biofuels and value-added metabolites using crude glycerol as a substrate at the anaerobic digestion process.
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Paranhos, Aline Gomes de Oliveira. "Produção otimizada de 1,3-propanodiol, ácido propiônico, etanol e hidrogênio, a partir de glicerol bruto e cultura mista, em reator anaeróbio de leito fluidificado". Universidade Federal de São Carlos, 2016. https://repositorio.ufscar.br/handle/ufscar/7746.
Testo completoAbstract (sommario):
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
This study aimed to optimize the production of hydrogen and other metabolites using crude glycerol as substrate, through design of experiments (DoE) and statistical process optimization. The first study aimed at optimizing the operational parameters of the fermentation process, and therefore, a mesophilic AFBR reactor was operated on 10 different phases, distributed as a combination of HRT and the glycerol concentration (Gc) proposed by a matrix containing CCD array containing 10 experimental trials. The HRT varied to 9.24h to 0.76h, while Gc ranged from 17.1g / L to 2.9 g / L. The results showed that the maximum conversion of glycerol (CG), 98.4%, was obtained using substrate concentrations lower than 5.0 g/L. The maximum yield (0.17 mol H2 / mol consumed glycerol) and H2 content in the produced biogas (87.4%) were achieved at concentrations greater than 10.0 g/L and HRT of 5h. Among the main soluble metabolites produced, 1,3-propanediol (1,3-PD) and propionic acid (HPr) stood out. The maximum yield of 1,3-PD (1.05 mol 1,3-PD / mol consumed glycerol) was obtained with 10.0 g/L glycerol in HRT of 9,24h, whereas the maximum yield of HPr (0.71 mol HPr / mol consumed glycerol) was achieved with 15.0 g/L of glycerol and HRT of 2h. The second study, in turn, consisted of optimizing the culture medium components (glycerol, KH2PO4, yeast extract and vitamin B12), through batch tests, and subsequent application in AFBR reactor. The maximum hydrogen and ethanol yields, 0.006 and 0.291 mol / mol consumed glycerol, was obtained in optimal culture medium consisting of 26.53 g/L glycerol, 1.75 g/L KH2PO4, 0.0076 g/L B12 and 0.5 g/L yeast extract. The application of optimal culture medium in a continuous reactor did not result in improvement of H2 and ethanol yields, however, caused an increase in 1,3-PD yield, reaching a maximum of 0.38 mol 1.3-PD / mol consumed glycerol.
O presente trabalho teve como objetivo otimizar a produção de hidrogênio e outros metabólitos, utilizando glicerol bruto como substrato, empregando técnicas de planejamento experimental e otimização estatística de processos. O primeiro estudo visou a otimização de parâmetros operacionais do processo fermentativo, e para tanto, um reator RALF mesofílico foi operado em 10 fases distintas, distribuídas conforme uma combinação do TDH e da concentração de glicerol (Cg) proposta por uma matriz de um DCCR contendo 10 condições experimentais. O TDH variou de 9,24h a 0,76h, enquanto a Cg variou de 17,1 g/L a 2,9 g/L. Os resultados obtidos mostraram que a máxima conversão de glicerol (CG), 98,4%, foi obtida utilizando concentrações de substrato menores que 5,0 g/L. O máximo rendimento (0,17 mol H2/mol glicerol consumido) e conteúdo de H2 no biogás produzido (87,4%) foram atingidos em concentrações superiores a 10,0 g/L e TDH de 5h. Dentre os principais metabólitos solúveis produzidos, 1,3-propanodiol (1,3-PD) e ácido propiônico (HPr) se destacaram. O máximo rendimento de 1,3-PD (1,05 mol 1,3-PD/mol glicerol consumido) foi obtido com 10,0 g/L de glicerol em TDH de 9,24h, enquanto que o máximo rendimento de HPr (0,71 mol HPr/mol glicerol consumido) foi alcançado com 15,0 g/L de glicerol e TDH de 2h. O segundo estudo, por sua vez, consistiu na otimização de componentes do meio de cultura (glicerol, KH2PO4, extrato de levedura e vitamina B12), através de ensaios em batelada, e posterior aplicação em RALF. Os máximos rendimentos de H2 e etanol, 0,006 e 0,291 mol/mol glicerol consumido, foram obtidos em meio de cultura ótimo constituído por 26,53 g/L de glicerol, 1,75 de KH2PO4, 0,0076 g/L de B12 e 0,5 g/L de extrato de levedura. A aplicação do meio de cultura otimizado em reator contínuo não resultou na melhoria dos rendimentos de H2 e etanol, no entanto, ocasionou um aumento no rendimento de 1,3-PD, alcançando 0,38 mol 1,3-PD/mol glicerol consumido.
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Tsai, Cheng-Yu, e 蔡承祐. "Start-up and performance evaluation of the AFBR-AFMBR system treating low-strength municipal wastewater in Taiwan". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/04746276214735757313.
Testo completoAbstract (sommario):
碩士國立交通大學
環境工程系所
103
In the present study, an anaerobic fluidized bioreactor combined with an anaerobic fluidized membrane bioreactor (AFBR-AFMBR) was used to for treat municipal wastewater at ambient temperature. The objectives of this study were to evaluate the start-up time and the performance using zeolite as carriers and the performance of the AFBR-AFMBR. During the start-up period, the reactor system was operated in semi-continuous mode and at a hydraulic retention time (HRT) of 1 d and an organic loading rate (OLR) of 1 g/m3/d with influent chemical oxygen demand (COD) of 1000 mg COD/L (made by synthetic wastewater). The reactor system reached to steady state with a pH level of 7, COD removal efficiency higher than 90% and 1 L/d of the steady biogas production. The microorganisms were successfully attached onto the carrier. Thereafter, the reactor system was changed to continuous mode operation at 3.5 h of total HRT for treating municipal wastewater (73 to 220 mg COD/L) at ambient temperature ranged from 20 to 35oC. The reactor performance reached to 70 to 90% of COD removal, 96% of total suspended solids (TSS) removal and 0.13 L CH4/g CODremoved of specific methane production. The membrane module in AFMBR can be continuously used for 333 d at a flux of 10 LMH without chemical cleaning. Besides, the reactor system only needed 0.015 kWh/m3 of pumping energy requirement and can generate 0.0024 kWh/m3 of methane energy. The above results revealed that the AFBR-AFMBR is a high efficiency energy-saving system for treating municipal wastewater.
Libri sul tema "Afbrot"
1
Gunnlaugsson, Helgi. Afbrot og Íslendingar: Greinasafn í afbrotafræði. Reykjavík: Háskólaútgáfan, 2000.
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2
Gunnlaugsson, Helgi. Afbrot og Íslendingar: Greinasafn í afbrotafræði. Reykjavík: Háskólaútgáfan, 2000.
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Gunnlaugsson, Gísli Ágúst. Því dæmist rétt að vera: Afbrot, refsingar og íslenskt samfélag á síðari hluta 19. aldar. Reykjavík: Sagnfræðistofnun Háskóla Íslands, 1991.
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Kristjánsson, Jóhannes Kr. Brasilíufanginn. Reykjavík: Sena, 2010.
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5
Vedsegaard, Erik. Afbrudt Kode. Copenhagen: Litera, 2002.
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kontor, Denmark Undervisningsministeriet Økonomisk-statistisk, a cura di. Bevægelser inden for uddannelsessystemet i perioden 1981-1986: Overgange, fuldførelser og afbrud. København: Undervisningsministeriet, Økonomisk-statistisk kontor, 1989.
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Afbrot á Íslandi: Greinasafn í afbrotafræði. Reykjavík]: Háskólaútgáfan, 2008.
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Crane, Sheryl. God Overwinnaar: Hoe God Muren Afbrak Door Middel Van Een Gebedsdagboek. GW Christian Publications, 2022.
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Bevægelser inden for uddannelsessystemet i perioden 1981-1986: Overgange, fuldførelser og afbrud (Uddannelses statistik). Statens informationstjeneste [distributor, 1989.
Cerca il testo completoCapitoli di libri sul tema "Afbrot"
1
A. Ramadan, Nadeem, e Hadeel A. Al-Ameri. "Aflatoxins". In Aflatoxins - Occurrence, Detoxification, Determination and Health Risks. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.97292.
Testo completoAbstract (sommario):
The aflatoxin producing fungi Aspergillus flavus, A. parasiticus, and A. nomius, although they are also produced by other species of Aspergillus as well as by Emericella spp.(Telemorph). There are many types of aflatoxins, but the four main ones are aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2, while aflatoxin M1 (AFM1) and M2 (AFM2) are the hydroxylated metabolites of AFB1 and AFB2. Aflatoxin B1, which is a genotoxic hepatocarcinogen, which presumptively causes cancer by inducing DNA, adducts leading to genetic changes in target liver cells. Cytochrome-P450 enzymes to the reactive intermediate AFB1–8, 9 epoxide (AFBO) which binds to liver cell DNA, resulting in DNA adducts, metabolize AFB1 Ingestion of contaminated food is the main source of exposure to aflatoxins, which adversely affect the health of both humans and animals. The compounds can cause acute or chronic toxic effects of a teratogenic, mutagenic, carcinogenic, immunotoxic or hepatotoxic character. You can reduce your aflatoxin exposure by buying only major commercial brands of food and by discarding that look moldy, discolored, or shriveled.
Atti di convegni sul tema "Afbrot"
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MESDAGHINIA, ALIREZA, AMIR HOSSEIN, JALIL JAAFARI, MOHAMMAD HOSEINI e RAMIN NABIZADEH. "Influence of upflow velocity on performance and biofilm characteristics of Anaerobic Fluidized Bed Reactor AFBR in treating high strength wastewater". In Third International Conference on Advances In Civil, Structural and Environmental Engineering- ACSEE 2015. Institute of Research Engineers and Doctors, 2015. http://dx.doi.org/10.15224/978-1-63248-065-1-122.
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