Thermochemical and analytical approach to describe secondary slag phase formation and local process conditions in a full-scale BGL gasifier

2021 ◽  
Vol 217 ◽  
pp. 106833
Author(s):  
Daniel Harry Schwitalla ◽  
Stefan Guhl ◽  
Marcel Laabs ◽  
Markus Reinmöller ◽  
Jin Bai ◽  
...  
Keyword(s):  
Phase Formation ◽  
Analytical Approach ◽  
Slag Phase ◽  
Full Scale ◽  
Process Conditions ◽  
Local Process

Full Scale Investigations on Enhanced Biological Phosphorus Removal – P-Release in the Anaerobic Reactor

1994 ◽  
Vol 29 (7) ◽  
pp. 153-156 ◽  
Author(s):  
D. Wedi ◽  
P. A. Wilderer
Keyword(s):  
Phosphorus Removal ◽  
Full Scale ◽  
Process Conditions ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Anaerobic Reactor ◽  
P Release ◽  
Acinetobacter Sp ◽  
Biological Phosphorus ◽  
P Removal

Most of the fundamental processes responsible for enhanced biological phosphorus removal (EBPR) were obtained through laboratory tests under defined conditions with pure or enriched cultures. Acinetobacter sp. was identified as the most important group of bacteria responsible for bio-P removal. Full scale data showed, however, that laboratory results do not match full scale results well enough. There is a lack of data on the effects of sub-optimal process conditions such as inadequate availability of volatile fatty acids (VFA), high nitrate recycle, storm water inflow or low temperatures. In this paper the results of full scale experiments on P-release are presented and compared with theoretical values. Measurements at a full scale Phoredox-system showed a surprisingly low P-release in the anaerobic reactor. Only 4 to 10% of the phosphorus in the activated sludge was released in the bulk liquid. With laboratory batch-tests, a maximum of 20% of the P in the sludge could be released. It is assumed that under the prevailing process conditions either the fraction of Acinetobacter sp. was very small, or bacteria other than Acinetobacter sp. were responsible for the P-removal, or most of the phosphorus was bound chemically but mediated by biological processes.

Removal of sulphite-reducing clostridia spores by full-scale water treatment processes as a surrogate for protozoan (oo)cysts removal

2000 ◽  
Vol 41 (7) ◽  
pp. 165-171 ◽  
Author(s):  
W. A. Hijnen ◽  
J. Willemsen-Zwaagstra ◽  
P. Hiemstra ◽  
G. J. Medema ◽  
D. van der Kooij
Keyword(s):  
Water Treatment ◽  
Removal Efficiency ◽  
Water Quality Monitoring ◽  
Full Scale ◽  
Process Conditions ◽  
Safe Drinking Water ◽  
Unit Process ◽  
Treatment Processes ◽  
Scale Unit ◽  
Micro Organisms

At eight full-scale water treatment plants in the Netherlands the removal of spores of sulphite-reducing clostridia (SSRC) was determined. By sampling and processing large volumes of water (1 up to 500 litres) SSRC were detected after each stage of the treatment. This enabled the assessment of the removal efficiency of the full-scale unit processes for persistent micro-organisms. A comparison with literature data on the removal of Cryptosporidium and Giardia by the same type of processes revealed that SSRC can be considered as a potential surrogate. The average Decimal Elimination Capacity (DEC) of the overall treatment plants ranged from 1.3–4.3 log. The observed actual log removal of SSRC by the unit processes and the overall treatment at one of the studied locations showed that the level of variation in removal efficiency was approximately 2 log. Moreover, from the actual log removal values it was observed that a low SSRC removal by one unit process is partly compensated by a higher removal by subsequent unit processes at this location. SSRC can be used for identification of the process conditions that cause variation in micro-organism removal which may lead to process optimization. Further research is necessary to determine the optimal use of SSRC in water quality monitoring for the production of microbiologically safe drinking water.

scholarly journals Indicative Marker Microbiome Structures Deduced from the Taxonomic Inventory of 67 Full-Scale Anaerobic Digesters of 49 Agricultural Biogas Plants

2021 ◽  
Vol 9 (7) ◽  
pp. 1457
Author(s):  
Julia Hassa ◽  
Johanna Klang ◽  
Dirk Benndorf ◽  
Marcel Pohl ◽  
Benedikt Hülsemann ◽  
...  
Keyword(s):  
Stable Process ◽  
Process Condition ◽  
Full Scale ◽  
Process Models ◽  
Process Efficiency ◽  
Process Conditions ◽  
Rrna Gene ◽  
General Process ◽  
Specific Distribution ◽  
Biogas Plants

There are almost 9500 biogas plants in Germany, which are predominantly operated with energy crops and residues from livestock husbandry over the last two decades. In the future, biogas plants must be enabled to use a much broader range of input materials in a flexible and demand-oriented manner. Hence, the microbial communities will be exposed to frequently varying process conditions, while an overall stable process must be ensured. To accompany this transition, there is the need to better understand how biogas microbiomes respond to management measures and how these responses affect the process efficiency. Therefore, 67 microbiomes originating from 49 agricultural, full-scale biogas plants were taxonomically investigated by 16S rRNA gene amplicon sequencing. These microbiomes were separated into three distinct clusters and one group of outliers, which are characterized by a specific distribution of 253 indicative taxa and their relative abundances. These indicative taxa seem to be adapted to specific process conditions which result from a different biogas plant operation. Based on these results, it seems to be possible to deduce/assess the general process condition of a biogas digester based solely on the microbiome structure, in particular on the distribution of specific indicative taxa, and without knowing the corresponding operational and chemical process parameters. Perspectively, this could allow the development of detection systems and advanced process models considering the microbial diversity.

Establishing the Dependence of Output Parameters Depending on Local Process Conditions for Friction Stir Welding of Pure Copper Plates

2018 ◽  
Vol 1146 ◽  
pp. 32-37 ◽  
Author(s):  
Marius Adrian Constantin ◽  
Ana Boşneag ◽  
Eduard Niţu ◽  
Lia Nicoleta Boţilă
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Speed ◽  
Frictional Heating ◽  
Pure Copper ◽  
Fusion Welding ◽  
Process Conditions ◽  
Friction Stir ◽  
Local Process ◽  
Welding Processes

Welding copper and its alloys is usually difficult to achieve by conventional fusion welding processes because of high thermal diffusivity of the copper, which is at least 10 times higher than most steel alloys, in addition to this, there are the well-known disadvantages of conventional fusion welding represented by necessity of using alloying elements, a shielding gas and a clean surface. To overcome these inconveniences, Friction Stir Welding (FSW), a solid state joining process that relies on frictional heating and plastic deformation, is being explored as a feasible welding process. In order to achieve an increased welding speed and a reduction in tool wear, this process is assisted by another one (TIG) which generates and adds heat to the process. The research includes two experiments for the FSW process and one experiment for tungsten inert gas assisted FSW process. The process parameters that varied were the rotational speed of the tool [rpm] and the welding speed [mm/min] while the compressive force remained constant. The purpose of this paper is to correlate the evolution of temperature, tensile strength, elongation and microscopic aspect with the linear position on the joint (local process parameters) for each experimental case and then make comparisons between them, and to identify and present the set of process parameters that has the best mechanical properties for this material.

Evaluating the application of Microbacterium sp. strain BR1 for the removal of sulfamethoxazole in full-scale membrane bioreactors

2015 ◽  
Vol 72 (10) ◽  
pp. 1754-1761 ◽  
Author(s):  
A. Fenu ◽  
B. M. R. Donckels ◽  
T. Beffa ◽  
C. Bemfohr ◽  
M. Weemaes
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Membrane Bioreactors ◽  
Full Scale ◽  
Process Conditions ◽  
Municipal Wastewater Treatment ◽  
Viable Biomass ◽  
The One ◽  
Micro Organisms

Microbacterium sp. strain BR1 is a bacterial strain that recently received attention for its capability to mineralize sulfamethoxazole (SMX) and other sulfonamides. In this study, the survival of Microbacterium sp. in municipal sludge waters was tested in batch experiments to explore optimal process conditions. Inoculation of Microbacterium sp. was subsequently performed in a pilot membrane bioreactor (MBR) operated in two configurations: treating full-scale MBR permeate (post-treatment) and treating raw municipal wastewater. SMX removal by Microbacterium sp. could not be proved in any of the configurations, except for SMX concentrations far higher than the ones normally found in municipal wastewater. By use of molecular tools (fluorescence in situ hybridization analysis) a low capability to survive in activated sludge systems was assessed. After inoculation, Microbacterium sp. was reduced to a small fraction of the viable biomass. The observed growth rate appeared to be many times lower than the one of typical activated sludge micro-organisms. Possibilities of application in full-scale municipal wastewater treatment are scarce.

scholarly journals Wide-angle Reconfigurable Refraction by Silicon Fourier Metasurfaces

2021 ◽  
Vol 2015 (1) ◽  
pp. 012005
Author(s):  
A A Antonov ◽  
M V Gorkunov
Keyword(s):  
Analytical Approach ◽  
Numerical Solutions ◽  
Full Scale ◽  
Silicon Films ◽  
Angle Of Incidence ◽  
Wide Angle ◽  
Angular Range ◽  
Optical Setup ◽  
Fourier Harmonics ◽  
Rayleigh Hypothesis

Abstract We design metasurfaces based on silicon films with smooth relief described by several Fourier harmonics and study their ability to redirect the refracted light over a wide angular range controlled by subtle variations of the optical setup. We use semi-analytical approach based on the Rayleigh hypothesis as well as full-scale numerical solutions to optimize the relief shape. To illustrate the reconfigurability potential, we design metasurfaces efficiently redirecting the refracted light from 83° to −73° with respect to the normal, when the angle of incidence is varied from 0° to 2°, and from 80° to −74°, when the substrate permittivity is altered from 2.3 to 2.2.

Full scale experience of two stage thermophilic/mesophilic sludge digestion

1997 ◽  
Vol 36 (6-7) ◽  
pp. 449-456 ◽  
Author(s):  
Jürgen Oles ◽  
Norbert Dichtl ◽  
Hans-hermann Niehoff
Keyword(s):  
Degradation Process ◽  
Pilot Scale ◽  
Full Scale ◽  
Process Efficiency ◽  
Anaerobic Sludge ◽  
Process Conditions ◽  
Two Stage ◽  
Operational Conditions ◽  
Digestion Process ◽  
General Goals

The general goals of anaerobic sludge stabilisation are degradation of organic substances, reduction of solids, decrease of pathogenic bacterias, improvement of dewatering capabilities and production of biogas. The anaerobic degradation process can be divided in several steps with different optimum operational conditions. This gives the possibility to design treatment plants as a two-stage process, optimizing the process conditions in each step and thereby leading to an overall increase in process efficiency. Research results in lab scale and pilot scale have shown that a two-stage digestion process with a high loaded first thermophilic (50-55°C) stage and a second stage under mesophilic (35-37°C) conditions with sufficient retention time will lead to the best results. After giving a short summary of the development of the two-stage thermophilic/mesophilic digestion process the paper will present full scale experiences with this system in Germany.

Biofilter Response to Upsets in Process Conditions

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Zarook M Shareefdeen
Keyword(s):  
Process Control ◽  
Dynamic Behavior ◽  
Flow Rate ◽  
Environmental Conditions ◽  
Full Scale ◽  
Axial Dispersion ◽  
Process Conditions ◽  
Operational Conditions ◽  
Dispersion Effects ◽  
Component Adsorption

Full scale biofilter systems are often subjected to variations in operational and environmental conditions. Occasional fluctuations in the flow rate, temperature, concentrations of process emissions, and pH drops are commonly encountered. In this work, a general transient biofilter model which incorporates axial dispersion effects, interactive kinetics, multi-component adsorption effects and oxygen limitations aspects have been used to study the dynamic behavior of biofilters to process upsets. Biofilter performance under sinusoidal and triangular perturbations of concentrations, flow rate, and media pH are presented. The results of this study will be useful in the designing and process control of biofilter systems that are exposed to varying operational conditions.

Going for mainstream deammonification from bench to full scale for maximized resource efficiency

2013 ◽  
Vol 68 (2) ◽  
pp. 283-289 ◽  
Author(s):  
B. Wett ◽  
A. Omari ◽  
S. M. Podmirseg ◽  
M. Han ◽  
O. Akintayo ◽  
...  
Keyword(s):  
Research Effort ◽  
Resource Efficiency ◽  
Full Scale ◽  
Process Conditions ◽  
Intermittent Aeration ◽  
Resource Saving ◽  
Operation Modes ◽  
Metabolic Route ◽  
And Performance ◽  
Nitrite Oxidizers

A three-pronged coordinated research effort was undertaken by cooperating utilities at three different experimental scales investigating bioaugmentation, enrichment and performance of anammox organisms in mainstream treatment. Two major technological components were applied: density-based sludge wasting by a selective cyclone to retain anammox granules and intermittent aeration to repress nitrite oxidizers. This paper evaluates process conditions and operation modes to direct more nitrogen to the resource-saving metabolic route of deammonification.

Monitoring the variations of the oxygen transfer rate in a full scale membrane bioreactor using daily mass balances

2011 ◽  
Vol 63 (11) ◽  
pp. 2651-2657 ◽  
Author(s):  
Y. Racault ◽  
A.-E. Stricker ◽  
A. Husson ◽  
S. Gillot
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Membrane Bioreactor ◽  
Oxygen Transfer Rate ◽  
Full Scale ◽  
Process Conditions ◽  
Aeration Tank ◽  
Oxygen Balance ◽  
Mass Balances ◽  
Total N

Oxygen transfer in biological wastewater treatment processes with high sludge concentration, such as membrane bioreactor (MBR), is an important issue. The variation of α-factor versus mixed liquor suspended solids (MLSS) concentration was investigated in a full scale MBR plant under process conditions, using mass balances. Exhaustive data from the Supervisory Control And Data Acquisition (SCADA) and from additional online sensors (COD, DO, MLSS) were used to calculate the daily oxygen consumption (OC) using a non-steady state mass balance for COD and total N on a 24-h basis. To close the oxygen balance, OC has to match the total oxygen transfer rate (OTRtot) of the system, which is provided by fine bubble (FB) diffusers in the aeration tank and coarse bubbles (CB) in separate membrane tanks. First assessing OTRCB, then closing the balance OC=OTRtot allowed to calculate OTRFB and to fit an exponential relationship between OTRFB and MLSS. A comparison of the α-factor obtained by this balance method and by direct measurements with the off-gas method on the same plant is presented and discussed.

Sign in / Sign up

Export Citation Format

Share Document