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Treatment of phenolic wastewater in suspended and fixed bed bioreactors

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Book Series: Karlsruher Berichte zur Ingenieurbiologie / Institut für Ingenieurbiologie und Biotechnologie des Abwassers, Universität Karlsruhe ISSN: 01728709 ISBN: 9783866443167 Year: Volume: 45 Pages: XXXIII, 134 p. DOI: 10.5445/KSP/1000009916 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Astronomy (General)
Added to DOAB on : 2019-07-30 20:01:58
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Phenol and chlorophenols are among the most important class of raw materials in chemical industry. These compounds also list among priority pollutants. The main problem in treating phenol or chlorophenol containing wastewater is the toxicity it exerts to the microbial flora in biological treatment plants. This may lead to partial or complete treatment plant failure, when the microbial flora is not adapted to phenol concentrations in the influent. The purpose of this thesis was to adapt the microbial flora of domestic sewage sludge to phenol and 2-chlorophenol at high concentration under continuous feeding conditions for long time periods and to study the response of suspension and fixed biofilm systems to transient loading and operation.

Hydrodynamic processes at the water-sediment interface of streambeds

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Book Series: Dissertationsreihe am Institut für Hydromechanik der Universität Karlsruhe / Universität Karlsruhe (TH), Institut für Hydromechanik ISSN: 14394111 ISBN: 9783866442443 Year: Volume: 2008/1 Pages: IV, 153 p. DOI: 10.5445/KSP/1000008267 Language: GERMAN
Publisher: KIT Scientific Publishing
Subject: General and Civil Engineering
Added to DOAB on : 2019-07-30 20:02:00
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Simultaneous 2D pressure and 2D velocity information at the rough water-sediment interface of streambeds were gained by a newly developed measurement setup. In the bed the pressure fluctuations decay exponentially within the first 1-2 equivalent sand roughnesses. Structural findings concerning coherent flow structures are consistent with models originally developed for smooth walls. A significant bed destabilizing flow-pressure pattern was identified for the first time.

Degradation of whey in an anaerobic fixed bed (AnFB) reactor

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Book Series: Karlsruher Berichte zur Ingenieurbiologie ISSN: 01728709 ISBN: 3937300120 Year: Volume: 41 Pages: XIII, 135 p. DOI: 10.5445/KSP/1592004 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Astronomy (General)
Added to DOAB on : 2019-07-30 20:02:02

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An Anaerobic Fixed Bed (AnFB) reactor was run as an upflow anaerobic reactor with an arrangement of supporting material for growth of a biofilm. The supporting material was made from Liapor-clay-polyethylene sinter lamellas (Herding Co., Amberg).The AnFB reactor was used for treating high concentrations of whey-containing wastewater. Optimal operating conditions for whey treatment at a concentration of COD in the influent of around 50 g whey·l-1 were found for a hydraulic retention time (HRT) in the range of 4-8 days or an organic loading rate (OLR) less than 10 kg COD·m-3·d-1. This is a higher load than normally applied in praxis reactors.Accumulation of volatile fatty acids (VFAs) happened when the AnFB was supplied with surplus whey solution at a high OLR or when it was oxygenated. VFAs were accumulated faster when the HRT was changed from 12 days to 6 days compared to a change of HRT from 6 days to 4 days. However, at a HRT of 6 days, the accumulated VFAs were completely degraded after an adaptation period of about 5 days, whereas the accumulated VFAs at a HRT of 4 days remained constant upon time and could not be degraded during further incubation.The conversion process (acetogenesis and methanogenesis) of VFAs was influenced by the pH in the reactor. Acetate and n-Butyrate were converted faster at neutral or slightly alkaline pH, while propionate was degraded faster at slightly acidic pH-value. The population in the AnFB contained hydrogen-utilizing methanogenic bacteria, formate-utilizing methanogenic bacteria, methanol-utilizing methanogenic bacteria, acetoclastic methanogenic bacteria and sulfate-reducing bacteria as the final-stage organism of whey degradation. Acetogenic and methanogenic bacteria grew slower and were present at much lower numbers than acidogenic bacteria. This made the acid degradation rate less than the acid production rate. The minimal HRT in the whey reactor was thus dependent on acid degradation rates. Acetate-utilizing methanogens seemed to be unable to grow as single cells. They preferred to grow in a particulate or attached manner on a support material. The biofilm on the support materials provided a lower redox potential and an anaerobic environment that was obligately needed by these bacteria. The addition of a reducing agent was necessary to keep the few culturing acetoclastic methanogens in suspended cultures active.H2/CO2 was the best methanogenic substrate for the bacteria in the effluent suspension of whey reactor, followed by formate and methanol. The least degradable substrate in suspension cultures was acetate. The optimal H2 gas concentration for methanogens was provided at 2.25 bar.Ferric ions addition or the addition of a mix of minerals improved acetate degradation and methane production rates more than two-folds. The redox potential + reducing agent was low enough for methanogenesis. An AnFB-reactor would be a suitable means for stabilizing wastewater from dairy processing. Liapor-clay-polyethylene sinter lamellas in a regularly arrangement could be the substratum for biofilm formation. A minimum HRT of 4-6 days should be planned or a maximum OLR rate 10 kg COD·m-3·d-1 not exceeded.

Nitrification in Fixed Bed Reactors Treating Saline Wastewater

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Book Series: Karlsruher Berichte zur Ingenieurbiologie / Institut für Ingenieurbiologie und Biotechnologie des Abwassers, Karlsruher Institut für Technologie ISSN: 01728709 ISBN: 9783866446915 Year: Volume: 47 Pages: XXIV, 173 p. DOI: 10.5445/KSP/1000023321 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Astronomy (General)
Added to DOAB on : 2019-07-30 20:01:58
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Two fixed bed reactors for nitrification with either polyethylene/clay sinter lamellas (FBR A) or porous ceramic rings (FBR B) were continously run for treating synthetic saline wastewater. Seawater from Hafen Büsum was used as an inoculums. The performance of the system was evaluated under different operating conditions. A better overall nitrification without nitrite accumulation was observed in FBR B during continuous incubation. However, in term of ammonia (AOR) and nitrite oxidation rates (NOR) that were determined in batch incubations, FBR A revealed a higher AOR and NOR of 6 and 7 mg N L-1 h-1, compared to the AOR and NOR of 5 and 5.9 mg N L-1 h-1 in FBR B, respectively. For studies of the effect of fluctuating salinity on the nitrification, polyethylene/clay sinter lamellas or porous ceramic rings from FBR A and B, respectively, were used as a source of immobilized nitrifiers. Salt concentrations were decreased from 3.5% to 0.03% via 2, 1 and 0.5% and increased from 3.5% to 5, 7 and 9%. A similar result for AOR and NOR during batch incubation was obtained for both substrata in FBR A and FBR B. The salinity changes influenced more the nitrite oxidizing bacteria (NOB) than the ammonia oxidizing bacteria (AOB). Measurement of oxidation rates during changing conditions show that the NORs were always higher than the AORs in all reactors, especially in initial phase. However, NORs were more sensitive to the salinity fluctuation than AORs, especially at lower salinity. The AORs remained constant for 0.5-3.5% NaCl and dropped to 70% and 68.5% after the salt concentration was brought to 0.034 or 5%, respectively. The NORs decreased significantly to 62% and 87.5% of initial rates after the salt concentration was changed to 2 and 5%, respectively.Non-halotolerant nitrifiers reactors with fresh polyethylene/clay as supporting material were inoculated with water samples taken from a ""Brackwasser""-location at the North Sea and were continuously run. The salt content in medium was 0% at the start and was then increased up to 10.5%. Increases of the salt concentration in a non-salt-adapted FBR suppressed more to NOR than AOR. When salinity was increased from 0.03% to 0.5, 1 and 2%, AORs remained constant. The AORs were approx. 90% of initial rates after the salt concentrations were increased stepwise to 3.5%, whereas the NORs decreased to 85, 52 and 36% of initial rate after salinity was increased to 1, 2 and 3.5%, respectively.

Controversies and Perspectives in the Use of Postoperative Radiotherapy for Prostate Cancer

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889454501 Year: Pages: 74 DOI: 10.3389/978-2-88945-450-1 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Oncology
Added to DOAB on : 2018-11-16 17:17:57
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The use of radical prostatectomy in patients with high risk of recurrence has significantly increased during the past 10 years. Thus, adjuvant radiation as a part of multimodality treatment or salvage radiation at the evidence of prostate-specific antigen (PSA) progression represents mainstay curative-intent options for a great number of prostate cancer patients. Although, few randomized trials and many retrospective studies have been published, many uncertainties still mold the discussions on the best treatment management for men after prostatectomy. This research topic successfully intended to foster discussions on current controversies in the use of postoperative radiotherapy and to present novel perspectives for treatment optimization.

Combining Fischer-Tropsch Synthesis (FTS) and Hydrocarbon Reactions in one Reactor

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ISBN: 9783866443303 Year: Pages: IV, 170 p. DOI: 10.5445/KSP/1000010082 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Chemical Engineering
Added to DOAB on : 2019-07-30 20:02:02
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The present study addresses the combination of low-temperature Fischer-Tropsch synthesis (FTS) and hydrocarbon modification reactions (hydroprocessing) in one reactor. The objective of the present investigation was to study the influence of CO during hydroprocessing reactions of hydrocarbon model compounds on two different bifunctional catalysts. In addition, the influence of the catalyst-bed configuration for the combination FTS and hydrocarbon reactions was investigated.

Engineering Fluid Dynamics

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ISBN: 9783038426684 9783038426691 Year: Pages: 210 DOI: 10.3390/books978-3-03842-669-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Chemical Engineering
Added to DOAB on : 2018-01-31 13:09:30
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This book contains the successful submissions to a Special Issue of Energies on the subject area of “Engineering Fluid Dynamics”. The topic of engineering fluid dynamics includes both experimental as well as computational studies. Of special interest were submissions from the fields of mechanical, chemical, marine, safety, and energy engineering. We welcomed both original research articles as well as review articles. After one year, 22 papers were submitted and 12 were accepted for publication. The average processing time was 65.2 days. The authors had the following geographical distribution: China (four); Italy (two); Korea (one); Germany (one); UK (one); Ireland (one); Australia (one); Sweden (one); Japan (one); Spain (one); Norway (one).Papers covered topics such as heat transfer in shell and helically coiled tube heat exchangers, the multiphase modeling of sprays, flashing flows, as well as mixing in a bubbling fluidized bed. Two papers related to heating ventilation and air condition (HVAC) are included, namely evaporation and condensation in the underfloor space of detached houses and air distribution in a railway vehicle. Three papers dealt with various aspects of pumps and turbines: a performance prediction method for pumps as turbines; noise radiation in a centrifugal pump; periodic fluctuations in energy efficiency in centrifugal pumps; and study of a high-pressure external gear pump. One paper used both laser doppler velocimetry (LDV) and CFD in the study of flow behind a semi-circular step cylinder. Finally, a paper investigated the influence of the equivalence ratio (ER) and feedstock particle size on birch wood gasification.

Turbulence in River and Maritime Hydraulics

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ISBN: 9783038975946 Year: Pages: 296 DOI: 10.3390/books978-3-03897-595-3 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: General and Civil Engineering --- Technology (General)
Added to DOAB on : 2019-03-21 15:50:41
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Understanding of the role of turbulence in controlling transport processes is of paramount importance for the preservation and protection of aquatic ecosystems, the minimization of the deleterious consequences of anthropogenic activity, and the successful sustainable development of river and maritime areas. In this context, the present Special Issue collects 15 papers which provide a representation of the present understanding of turbulent processes and their effects in river and maritime environments. The presented collection of papers is not exhaustive, but it highlights the key priority areas and knowledge gaps in this field of research. The published papers present the state-of-the-art knowledge of complex environmental flows which are useful for researchers and practitioners. The paper contents are an overview of some recent topics of research and an exposure of the current and future challenges associated with these topics.

Keywords

breaking waves --- turbulence invariants --- laboratory experiments --- flow-through system --- tidal inlets --- residence time --- coastal lagoon --- MIKE 3 FM (HD & --- TR) --- MIKE 21 FM (HD) --- dense jet --- current flow --- velocity --- trajectory --- turbulence --- dissipation --- rivers --- meanders --- turbulence --- secondary motion --- prediction --- bedrock canyon --- ADCP --- eddy viscosity --- bed shear stress --- spatial analysis --- smoothed particle hydrodynamics models --- physical modelling --- plunging breaking waves --- vorticity --- turbulent jet --- wave–current interaction --- spectral dissipation --- bottom friction --- numerical model --- hydrodynamic model --- spectral model --- wave attenuation --- energy dissipation --- drag coefficient --- flexible vegetation --- Spartina maritima --- vegetation patch --- wake region --- submerged ratio --- SVF --- channel confluences --- junction angle --- flow deflection zone --- flow retardation zone --- flow separation zone --- numerical modelling --- PANORMUS --- jets --- waves --- turbulence --- mixing --- diffusion --- advection --- river mouth --- flow mixing --- nonlinear shallow water equations --- macrovortices --- sub-grid turbulence --- seabed friction --- flow resistance --- roughness --- gravel-bed rivers --- casting technique --- CFD --- Kelvin–Helmholtz --- billow --- lobe --- cleft --- gravity current --- surface waves --- inclined negatively buoyant jets --- regular waves --- dilution --- sea discharges --- rivers --- maritime areas --- turbulent processes

Process Design, Integration, and Intensification

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ISBN: 9783038979821 / 9783038979838 Year: Pages: 188 DOI: 10.3390/books978-3-03897-983-8 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-06-26 08:44:06
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With the growing emphasis on enhancing the sustainability and efficiency of industrial plants, process integration and intensification are gaining additional interest throughout the chemical engineering community. Some of the hallmarks of process integration and intensification include a holistic perspective in design, and the enhancement of material and energy intensity. The techniques are applicable for individual unit operations, multiple units, a whole industrial facility, or even a cluster of industrial plants. This book aims to cover recent advances in the development and application of process integration and intensification. Specific applications are reported for hydraulic fracturing, palm oil milling processes, desalination, reactive distillation, reaction network, adsorption processes, herbal medicine extraction, as well as process control.

Multiscale and Innovative Kinetic Approaches in Heterogeneous Catalysis

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ISBN: 9783039211791 / 9783039211807 Year: Pages: 214 DOI: 10.3390/books978-3-03921-180-7 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Technology (General) --- General and Civil Engineering
Added to DOAB on : 2019-08-28 11:21:27
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Kinetics and reactor modeling for heterogeneous catalytic reactions are prominent tools for investigating and understanding catalyst functionalities at nanoscale and the related rates of complex reaction networks. This book illustrates some examples related to the transformation of simple to more complex feedstocks, including different types of reactor designs, i.e., steady-state, transient plug flow reactors, and TAP reactors for which there is sometimes a strong gap in the operating conditions from ultra-high-vacuum to high-pressure conditions. In conjunction, new methodologies have emerged, giving rise to more robust microkinetics models. As exemplified, they include the kinetics and the dynamics of the reactors and span a large range of length and time scales. The objective of this Special Issue is to provide contributions that can illustrate recent advances and novel methodologies for elucidating the kinetics of heterogeneous reactions and the necessary multiscale approach for optimizing the reactor design. This book is dedicated to postgraduate and scientific researchers, and experts in heterogeneous catalysis. It may also serve as a source of original information for the elaboration of lessons on catalysis for Master students.

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