A Critical Look into the Deviation of Full Scale Performance from Design Expectations

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1389-1402 ◽  
Author(s):  
R. Zaloum
Keyword(s):  
Expert Systems ◽  
Waste Treatment ◽  
Full Scale ◽  
Operating Conditions ◽  
Organic Load ◽  
Computer Assisted ◽  
Uniform Load ◽  
Effluent Quality ◽  
Simulation Techniques ◽  
Steady Level

Deviations from design expectations appear to stem from views which assume that a unique response should result from a given set of operating conditions. The results of this study showed that two systems operating at equal organic loads or F/M ratios and at the same SRT do not necessarily give equal responses. This deviation was linked to the manner in which the HRT and influent COD are manipulated to obtain a constant or uniform load, and to subtle interactions between influent COD, HRT and SRT on the biomass and effluent responses. Increases of up to 200% in influent COD from one steady level to the next did not significantly influence the effluent VSS concentration while an effect on filtered COD was observed for increases as low as 20%. Effluent TKN and filtered COD correlated strongly with the operating MLVSS while phosphorus residual depended on the operating SRT and the organic load removed. These results point to the inadequacy of traditional models to predict effluent quality and point to the need to consider these effects when developing simulation techniques or computer assisted expert systems for the control of waste treatment plants.

Characterization, Digestibility and Anaerobic Treatment of Leachates from Old and Young Landfills

1989 ◽  
Vol 21 (4-5) ◽  
pp. 145-155 ◽  
Author(s):  
R. Méndez ◽  
J. M. Lema ◽  
R. Blázquez ◽  
M. Pan ◽  
C. Forjan
Keyword(s):  
Anaerobic Digestion ◽  
Anaerobic Treatment ◽  
Full Scale ◽  
Operating Conditions ◽  
Organic Load ◽  
Anaerobic Filter ◽  
Standards Of Living ◽  
Landfill Sites

We have evaluated the utility of applying anaerobic digestion treatment to the leachates from two landfill sites receiving solid urban refuse from populations of similar standards of living. Both tips are located in the same area and have very similar climates, but they differ as regards the length of time they have been operated. The leachates from the older tip have much lower levels of organic load, 40% of which was refractory to the anaerobic digestion treatment applied. The digestibility of leachates was studied by using a semicontinuous suspended sludge system.It was possible to remove up to 65% of the soluble COD of leachates from the young tip by means of an anaerobic filter working at HRTs less than 2 days. This system proved to be highly stable when its operating conditions were subjected to perturbations similar to those likely to be suffered by a full-scale plant.

Reliability analysis of stabilisation pond systems

2007 ◽  
Vol 55 (11) ◽  
pp. 127-134 ◽  
Author(s):  
S.M.A.C. Oliveira ◽  
M. von Sperling
Keyword(s):  
Reliability Analysis ◽  
Coefficient Of Variation ◽  
High Variability ◽  
Full Scale ◽  
Operating Conditions ◽  
Effluent Quality ◽  
Standard Values ◽  
Expected Compliance

This article presents a reliability analysis of 116 full-scale pond systems in Brazil, comprising 73 primary facultative ponds and 43 anaerobic–facultative pond systems. A methodology developed by Niku et al. (1979) is used for the determination of the coefficients of reliability, in terms of the compliance of effluent BOD, COD, TSS and FC to discharge standards or effluent quality targets. The design concentrations necessary to meet the prevailing discharge standards and the expected compliance percentages have been calculated from the coefficients of reliability obtained. The results showed that few units, under the observed operating conditions, would be able to present reliable performances in terms of compliance with the analyzed standards. For the four constituents (BOD, COD, TSS and FC) and both systems (facultative ponds and anaerobic-facultative systems), the variability of the effluent quality was very large, leading to a high variability of the coefficient of variation (CV) and the coefficient of reliability (COR). The effluent quality from the facultative ponds showed a larger distance to both the desired values and the discharge standard values, compared with the anaerobic–facultative systems.

Design and operating experiences of municipal MBRs in Europe

2008 ◽  
Vol 58 (12) ◽  
pp. 2319-2327 ◽  
Author(s):  
H. Itokawa ◽  
C. Thiemig ◽  
J. Pinnekamp
Keyword(s):  
Membrane Bioreactor ◽  
Membrane Damage ◽  
Full Scale ◽  
Operating Conditions ◽  
Small Scale ◽  
Membrane Unit ◽  
Effluent Quality ◽  
Membrane Flux ◽  
The Moment ◽  
And Control

The number of membrane bioreactor (MBR) installations is increasing worldwide, not only for small-scale industrial WWTPs but also for larger-scale municipal WWTPs. In Europe, MBR has been installed in municipal WWTPs since late 1990s, and more than 100 full-scale plants are operated at the moment. In this paper, present state of European municipal MBRs is described in terms of design and operating conditions, as well as operating problems and their solutions, based on the information collected from 17 full-scale WWTPs by interview and questionnaire survey. Decisive factors of MBR installation at these plants were footprint and effluent quality. Full-aerobic and pre-denitrification were the most common reactor configurations, nearly half of them being equipped with independent filtration tanks. Operating conditions of bioreactor and filtration, including membrane flux and cleaning strategy, were different from plant to plant, as a result of plant-specific optimization experiences, even among the similar type of membrane. Operating problems specific for MBR were reported, including blocking/failure of pre-screen, sludging/hair-clogging of membrane, damage on membrane unit, air in permeate pipes, as well as conventional troubles including occurrence of scum and initial trouble in instrumentation and control systems. Aspects for further optimization of MBR design were also pointed out by the operators.

scholarly journals The Utilization of Laundry Wastewater as Liquid Fertilizer for Rice Plants

2021 ◽  
Author(s):  
Sadono Mulyo ◽  
Suwarno Hadisusanto ◽  
Prabang Setiono
Keyword(s):  
Aquatic Ecosystems ◽  
Waste Treatment ◽  
Quality Standard ◽  
Operating Conditions ◽  
Treatment Model ◽  
Liquid Fertilizer ◽  
Effluent Quality ◽  
Rice Plants ◽  
Variable Quantity ◽  
Reduction Efficiency

Abstract The laundry liquid wastewater contains detergents and phosphates which are nutrients for plant which can also causepollution, explosive growth of aquatic biota, and aquatic ecosystems eutrophication. The great potential of laundrywaste requires an efficient and inexpensive waste treatment model to reduce the phosphate content. This study aimsto examine the effect of wetlands on laundry wastewater, straw soaking water, and the use of effluent as a liquidfertilizer for rice plants. As well as analyzing the fate of toxic detergents (ABS) in rice grains on a laboratory scale.The results showed the wetland was able to reduce the pollutants level in laundry wastewater and toxic organic bondswith the BOD, COD, TSS, TDS, Detergent, Phosphate reduction efficiency between 49% - 95%; has met the PERDADIY no. 7 of 2016 about Quality Standard. The operating conditions that provided the optimum results in this studywere the laundry wastewater treatment model and the utilization of effluent as liquid fertilizer for rice plants withstraw soaking water neutralization with minimum discharge variations resulting in effluent quality and quantity ofharvested products of 75 gr/0.4 m2 and there is a detergent residue content of 24.80 mg/kg; without straw soaking,yields 155 gr/0.4 m2 with detergent residue content of 32.65 mg/kg. Iconic and diagrammatic models of laundrywastewater treatment were obtained based on the quality variable, quantity variable, and the effluent pre-treatmentcapacity variable thus it can be used as liquid fertilizer for rice plants to describe the behavior of the real system. Thefactor that has a high influence on system performance, but the dependence between factors is low, namely the effluent flow discharge into the wetland.

Automatic buffer capacity based sensor for effluent quality monitoring

1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Buffer Capacity ◽  
Wastewater Treatment Plants ◽  
Data Interpretation ◽  
Full Scale ◽  
Quality Monitoring ◽  
Effluent Quality ◽  
Capacity Curves ◽  
On Line

The use of an automatic on-line titration unit for monitoring the effluent quality of wastewater plants is presented. Buffer capacity curves of different effluent types were studied and validation results are presented for both domestic and industrial full-scale wastewater treatment plants. Ammonium and ortho-phosphate monitoring of the effluent were established by using a simple titration device, connected to a data-interpretation unit. The use of this sensor as the activator of an effluent quality proportional sampler is discussed.

Variability control: key to regulatory compliance and sustainability goals

2006 ◽  
Vol 53 (11) ◽  
pp. 1-9 ◽  
Author(s):  
A.J. Englande ◽  
W.W. Eckenfelder ◽  
G. Jin
Keyword(s):  
Wastewater Treatment ◽  
Waste Treatment ◽  
Management Practice ◽  
Regulatory Compliance ◽  
Process Technology ◽  
Effluent Quality ◽  
Best Management ◽  
Performance Variability ◽  
Treatment Technologies ◽  
Biological Waste Treatment

The focus of this paper is on variability concerns in wastewater treatment and approaches to control unacceptable fluctuations in effluent quality. Areas considered include: factors contributing to variability in both waste loads and process technology performance; variability assessment; control of variability employing the process best management practice (BMP); design/operation of biological waste treatment technologies for variability reduction; and modelling to enhance process control.

Ultra-Low Emission Hydrogen/Syngas Combustion With a 1.3 MW Injector Using a Micro-Mixing Lean-Premix System

2011 ◽  
Author(s):  
Brian Hollon ◽  
Erlendur Steinthorsson ◽  
Adel Mansour ◽  
Vincent McDonell ◽  
Howard Lee
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Flame Temperature ◽  
Fuel Mixture ◽  
Full Scale ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Nitrogen Dilution ◽  
Fuel Mixtures

This paper discusses the development and testing of a full-scale micro-mixing lean-premix injector for hydrogen and syngas fuels that demonstrated ultra-low emissions and stable operation without flashback for high-hydrogen fuels at representative full-scale operating conditions. The injector was fabricated using Macrolamination technology, which is a process by which injectors are manufactured from bonded layers. The injector utilizes sixteen micro-mixing cups for effective and rapid mixing of fuel and air in a compact package. The full scale injector is rated at 1.3 MWth when operating on natural gas at 12.4 bar (180 psi) combustor pressure. The injector operated without flash back on fuel mixtures ranging from 100% natural gas to 100% hydrogen and emissions were shown to be insensitive to operating pressure. Ultra-low NOx emissions of 3 ppm were achieved at a flame temperature of 1750 K (2690 °F) using a fuel mixture containing 50% hydrogen and 50% natural gas by volume with 40% nitrogen dilution added to the fuel stream. NOx emissions of 1.5 ppm were demonstrated at a flame temperature over 1680 K (2564 °F) using the same fuel mixture with only 10% nitrogen dilution, and NOx emissions of 3.5 ppm were demonstrated at a flame temperature of 1730 K (2650 °F) with only 10% carbon dioxide dilution. Finally, using 100% hydrogen with 30% carbon dioxide dilution, 3.6 ppm NOx emissions were demonstrated at a flame temperature over 1600 K (2420 °F). Superior operability was achieved with the injector operating at temperatures below 1470 K (2186 °F) on a fuel mixture containing 87% hydrogen and 13% natural gas. The tests validated the micro-mixing fuel injector technology and the injectors show great promise for use in future gas turbine engines operating on hydrogen, syngas or other fuel mixtures of various compositions.

Numerical Characterization of Flow and Heat Transfer in Pre-Swirl Systems

2017 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Jacopo D’Errico
Keyword(s):  
Heat Transfer ◽  
Gas Turbines ◽  
Numerical Study ◽  
Physical Phenomenon ◽  
Computational Procedure ◽  
Operating Conditions ◽  
Simulation Techniques ◽  
Numerical Characterization ◽  
Unsteady Simulation

This paper deals with a numerical study aimed at the validation of a computational procedure for the aerothermal characterization of pre-swirl systems employed in axial gas turbines. The numerical campaign focused on an experimental facility which models the flow field inside a direct-flow pre-swirl system. Steady and unsteady simulation techniques were adopted in conjunction with both a standard two-equations RANS/URANS modelling and more advanced approaches such as the Scale-Adaptive-Simulation principle, the SBES and LES. The comparisons between CFD and experiments were done in terms of swirl number development, static and total pressure distributions, receiving holes discharge coefficient and heat transfer on the rotor disc surface. Several operating conditions were accounted for, spanning 0.78·106<Reφ<1.21·106 and 0.123<λt<0.376. Overall the steady-state CFD predictions are in good agreement with the experimental evidences even though it is not able to confidently mimic the experimental swirl and pressure behaviour in some regions. Although the use of unsteady sliding mesh and direct turbulence modelling, would in principle increase the insight in the physical phenomenon, from a design perspective the tradeoff between accuracy and computational costs is not always favourable.

scholarly journals Full-Scale Seawater Reverse Osmosis Desalination Plant Simulator

2020 ◽  
Author(s):  
Hammad Siddiqui ◽  
Mariam Elnour ◽  
Nader Meskin ◽  
Syed Zaidi
Keyword(s):  
Reverse Osmosis ◽  
Full Scale ◽  
Operating Conditions ◽  
Water Desalination ◽  
System Behavior ◽  
Desalination Plant ◽  
Local Plant ◽  
Seawater Reverse Osmosis ◽  
High Flexibility ◽  
Operational Data

Reverse Osmosis (RO) is an efficient and clean membrane-based technology for water desalination. This work presents a full-scale seawater reverse osmosis (SWRO) desalination plant simulator using MATLAB/Simulink that has been validated using the operational data from a local plant. It allows simulating the system behavior under different operating conditions with high flexibility and minimal cost.

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