Search results for "Aerobic"
showing 10 items of 760 documents
Effect of substrate improvement on optimising biogas yield from anaerobic digestion
2014
Masteroppgave i fornybar energi ENE 500 Universitetet i Agder 2014 The anaerobic digestion process involves the decomposition of the organic matter to yield biogas; gas that is mainly composed of methane and carbon dioxide with traces of some other gases. This process is used for different purposes including municipal waste treatment, wastewater treatment, fertilizer production, and farm wastes disposal as well as energy production. It is accomplished in three main stages; hydrolysis, acidogenesis and methanogenesis with each of the stages achieved by specific microorganisms that are active in limited ranges of operational and environmental conditions. These conditions are controlled to ach…
A Contribution to Environmental Protection Through the Valorisation of Kitchen Biowaste
2022
The worldwide interest in Renewable Energy Sources (RES) is gathering momentum. Anaerobic Digestion (AD) process is steadily growing, as more people are setting up bioreactors in order to produce biogas and digestate. AD process is the fermentation of solid biowaste in the absence of oxygen and is zero emission, i.e. it is CO2 neutral. The aim of this work is to test HomeBiogas 2.0, i.e. a revolutionary equipment that used the kitchen biowaste from the canteen of the agricultural institute of Marsala (Trapani, Italy). This equipment works as a continuous flow bioreactor: the waste is fed in one end, while biogas and digestate come out from the other. The process continuously took place at a…
Emissions of Greenhouse Gases and Climate Politics in the Latvian Waste Sector
2015
According IPCC guidelines for determination of greenhouse gases in waste management (IPCC 2006) the quantity of greenhouse gases must be determined for the emissions of CO2, CH4, N2O for such treatment activities: disposal of solid waste, biological treatment of solid waste and incineration and open burning of waste. Presented report reviles the current situation of this field in Latvia and conclusions on its minimization actions. The data received from Latvian environmental data bases shows that the quantity of disposed unsorted municipal waste is rising and created sanitary landfill system with anaerobic digestion of bio mas (the content of it in the disposed waste reaches 40–50 %) is pro…
Anaerobic moving bed biofilm reactor followed by aerobic granular sludge for brewery wastewater treatment
2018
Small and medium breweries discharging to municipal sewers without treatment generate significant loads with typical concentrations reported by Valta et al. (2014) as 2-6 g COD L-1, 25-80 mg TN L-1, 10-50 mg TP L-1, with pH between 4.5 and 12. Treatment of the high-strength wastewater requires specialized low footprint processes, such as aerobic granular sludge (AGS), capable of high-rate degradation, as well as simultaneous nitrogen and phosphorous removal (Wang et al., 2007). The objective of this study was to evaluate the start-up period of AGS receiving brewery wastewater after initial anaerobic pre-treatment.
Analysis of anaerobic power in club level young rowers
2013
Aim: To date, assessment of the anaerobic components to determine performance in rowers is not part of standard evaluation or monitoring set for training. The aim of this study was to evaluate the relation between anaerobic power output and ergometer rowing performance over 2000 meters, in a group of 14 -17 years old rowers (n = 11). Methods: Each subject performed, in three separate days, two “all-out” tests, over 20 and 60 seconds, and a 2000 meters trial, using a Concept II rowing ergometer. Mean power values over 20 sec (W20) and 60 sec (W60) were measured and compared with the time to perform the 2000 m trial (t2000). Results: Statistical analysis showed high and significant correlatio…
Requirement for the Proton-Pumping NADH Dehydrogenase I of Escherichia Coli in Respiration of NADH to Fumarate and Its Bioenergetic Implications
1997
In Escherichia coli the expression of the nuo genes encoding the proton pumping NADH dehydrogenase I is stimulated by the presence of fumarate during anaerobic respiration. The regulatory sites required for the induction by fumarate, nitrate and O2 are located at positions around –309, –277, and downstream of –231 bp, respectively, relative to the transcriptional-start site. The fumarate regulator has to be different from the O2 and nitrate regulators ArcA and NarL. For growth by fumarate respiration, the presence of NADH dehydrogenase I was essential, in contrast to aerobic or nitrate respiration which used preferentially NADH dehydrogenase II. The electron transport from NADH to fumarate …
Transport of C(4)-dicarboxylates in Wolinella succinogenes.
2000
ABSTRACT C 4 -dicarboxylate transport is a prerequisite for anaerobic respiration with fumarate in Wolinella succinogenes , since the substrate site of fumarate reductase is oriented towards the cytoplasmic side of the membrane. W. succinogenes was found to transport C 4 -dicarboxylates (fumarate, succinate, malate, and aspartate) across the cytoplasmic membrane by antiport and uniport mechanisms. The electrogenic uniport resulted in dicarboxylate accumulation driven by anaerobic respiration. The molar ratio of internal to external dicarboxylate concentration was up to 10 3 . The dicarboxylate antiport was either electrogenic or electroneutral. The electroneutral antiport required the prese…
Anaerobic respiration of Bacillus macerans with fumarate, TMAO, nitrate and nitrite and regulation of the pathways by oxygen and nitrate
1995
In Bacillus macerans, anaerobic respiratory pathways and the regulation of facultatively anaerobic catabolism by electron acceptors were analysed. In addition to fermentative growth, B. macerans was able to grow anaerobically by fumarate, trimethylamine N-oxide, nitrate, and nitrite respiration with glycerol as donor. During growth by fumarate respiration, a membrane-bound fumarate reductase was present that was different from succinate dehydrogenase. The end product of nitrate and nitrite respiration was ammonia. No N2 or NO and only traces of N2O could be detected. O2 repressed the activity of nitrate and fumarate reductases and the fermentation of glucose, presumably at the transcription…
Alternative respiratory pathways of Escherichia coli: energetics and transcriptional regulation in response to electron acceptors
1997
AbstractThe electron-transport chains of Escherichia coli are composed of many different dehydrogenases and terminal reductases (or oxidases) which are linked by quinones (ubiquinone, menaquinone and demethylmenaquinone). Quinol:cytochrome c oxido-reductase (`bc1 complex') is not present. For various electron acceptors (O2, nitrate) and donors (formate, H2, NADH, glycerol-3-P) isoenzymes are present. The enzymes show great variability in membrane topology and energy conservation. Energy is conserved by conformational proton pumps, or by arrangement of substrate sites on opposite sides of the membrane resulting in charge separation. Depending on the enzymes and isoenzymes used, the H+/e− rat…
Start-up and Operation of Laboratory-Scale Thermophilic Upflow Anaerobic Sludge Blanket Reactors Treating Vegetable Processing Wastewaters
1997
Thermophilic anaerobic treatment of hot vegetable processing wastewaters was studied in laboratory-scale UASB reactors at 55°C. The high-strength wastewater streams, deriving from steam peeling and blanching of carrot, potato and swede were used. The reactors were inoculated with mesophilic granular sludge. Stable thermophilic methanogenesis with about 60% COD removal was reached within 28 days. During the 134 day study period the loading rate was increased up to 24 kg COD m−3 day−1. High treatment efficiency of more than 90% COD removal and concomitant methane production of 7·3 m3 CH4 m−3 day−1 were achieved. The anaerobic process performance was not affected by the changes in the wastewat…