Search results for "reactors"

ABATEMENT OF ACID ORANGE 7 IN WATER BY DIFFERENT ELECTROCHEMICAL APPROACHES

2014

Very large amounts of synthetic dyes are discharged in the environment from industrial effluents [1]. Due to their large-scale production and extensive application, synthetic dyes can cause considerable nonaesthetic pollution and are serious health-risk factors [2]. Dyes are commonly classified from their chromophore group. The majority of these compounds consumed at industrial scale are azo (–N=N–) derivatives that represent more than 50% of the all dyes used in textile industries, although antraquinone, indigoide, triphenylmethyl, xanthene, sulphur and phtalocyanine derivatives are frequently utilized [3]. Since dyes usually present high stability under sunlight and resistance to microbia…

Hydrothermal liquefaction of municipal sludge in sub- and super- critical water

2020

Hydrothermal liquefaction of municipal sludge was conducted to investigate the effects of sub- and supercritical water and of the fluid dynamic regime on the quality of the products. Preliminary experimental runs were performed at two different temperatures (350°C and 400°C) changing reaction time in order to work at fixed kinetic severity of the process. An improvement of the C content in the solid residues and of the ratio H/C of the biocrude was obtained when a stirred reactor was used both in sub- and supercritical water. A hydrocarbon fraction was separated from biocrude whose maximum yield of 25% w/w was achieved in supercritical conditions. Results showed that the cumulative energy r…

Determination of β-decay ground state feeding of nuclei of importance for reactor applications

2020

In β-decay studies the determination of the decay probability to the ground state (g.s.) of the daughter nucleus often suffers from large systematic errors. The difficulty of the measurement is related to the absence of associated delayed γ-ray emission. In this work we revisit the 4πγ−β method proposed by Greenwood and collaborators in the 1990s, which has the potential to overcome some of the experimental difficulties. Our interest is driven by the need to determine accurately the β-intensity distributions of fission products that contribute significantly to the reactor decay heat and to the antineutrinos emitted by reactors. A number of such decays have large g.s. branches. The method is…

Electrochemical incineration of oxalic acid in a micro gap flow cell

2009

Innovative sequential batch reactor solutions for wastewater treatment

2019

Sekwencyjne biologiczne reaktory (SBR) są szeroko wykorzystywane do oczyszczania ścieków, które obecnie stają się zanieczyszczone coraz to nowymi i bardziej złożonymi substancjami. Korzystne zatem staje się włączenie różnego rodzaju rozszerzających się konfiguracji oraz modyfikacji operacyjnych, aby efektywniej oczyszczać ścieki. W pracy przedstawiono podstawowy opis procesu SBR oraz jego modyfikacji, które prowadzą do lepszego usuwania powstających zanieczyszczeń. Scharakteryzowano cykliczny system osadów czynnych (CASS), który jest jednym z najpopularniejszych procesów reaktorów sekwencyjnych (SBR) stosowanych do oczyszczania ścieków komunalnych oraz ścieków z różnych branż, w tym rafiner…

Methods to enhance hydrolysis during one and two-stage anaerobic digestion of energy crops and crop residues

2011

Mass transfer and hydrodynamic characteristics of a Long Draft Tube Self-ingesting Reactor (LDTSR) for gas-liquid-solid operations

2011

Gas-liquid stirred vessels are widely employed to carry out chemical reactions involving a gas reagent and a liquid phase. The usual way for introducing the gas stream into the liquid phase is through suitable distributors placed below the impeller. An interesting alternative is that of using “self ingesting” vessels where the headspace gas phase is injected and dispersed into the vessel through suitable surface vortices. In this work the performance of a Long Draft Tube Self-ingesting Reactor dealing with gas-liquid-solid systems, is investigated. Preliminary experimental results on the effectiveness of this contactor for particle suspension and gas-liquid mass transfer performance in pres…

Influence of Viscosity on Mass Transfer Performance of Unbaffled Stirred Vessels

2013

Unbaffled stirred tanks are seldom employed in the process industry as they are considered poorer mixers than baffled vessels. However they may be expected to provide significant advantages in a wide range of applications (e.g. crystallization, food and pharmaceutical processes, etc) where the presence of baffles is often undesirable. Moreover, in plants or animal cell cultivation bioreactors, where cell damage is often caused by bursting bubbles at the air –medium interface (Barret et al., 2010), they can provide sufficient mass transfer through the free surface vortex, so bubble formation and subsequent bursting inside the reactor can be conveniently avoided (Scargiali et al., 2012). In t…

Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems

2007

The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The results indicated the feasibility of the UASB-septic tank for (pre)treatment of black water at low temperatures with respect to removal of suspended solids and dissolved organic material. Inoculum sludge had little effect on COD(ss) removal, though in the start-up phase some poorly adapted inoculum disintegrated and washed out, thus requiring consideration when designing the process. Removal of …