ASM1 dynamic calibration and long-term validation for an intermittently aerated WWTP

2006 ◽  
Vol 53 (12) ◽  
pp. 247-256 ◽  
Author(s):  
A. Marquot ◽  
A.-E. Stricker ◽  
Y. Racault
Keyword(s):  
Treatment Plant ◽  
Simulation Software ◽  
Biological Nutrient Removal ◽  
Model Parameters ◽  
Dynamic Calibration ◽  
Biological Degradation ◽  
Data Set ◽  
Degree Of Confidence ◽  
High Degree

Activated sludge models, and ASM1 in particular, are well recognised and useful mathematical representations of the macroscopic processes involved in the biological degradation of the pollution carried by wastewater. Nevertheless, the use of these models through simulation software requires a careful methodology for their calibration (determination of the model parameters' values) and the validation step (verification with an independent data set). This paper presents the methodology and the results of dynamic calibration and validation tasks as a prior work to a modelling project for defining a reference guideline destined to French designers and operators. To reach these goals, a biological nutrient removal (BNR) wastewater treatment plant (WWTP) with intermittent aeration was selected and monitored for 2 years. Two sets of calibrated parameters are given and discussed. The results of the long-term validation task are presented through a 2-month simulation with lots of operation changes. Finally, it is concluded that, even if calibrating ASM1 with a high degree of confidence with a single set of parameters was not possible, the results of the calibration are sufficient to obtain satisfactory results over long-term dynamic simulation. However, simulating long periods reveals specific calibration issues such as the variation of the nitrification capacity due to external events.

scholarly journals Long-term observation of midlatitude quasi 2-day waves by a water vapor radiometer

2018 ◽  
Vol 18 (16) ◽  
pp. 12061-12074 ◽  
Author(s):  
Martin Lainer ◽  
Klemens Hocke ◽  
Niklaus Kämpfer
Keyword(s):  
Water Vapor ◽  
Large Fraction ◽  
Dynamical Behavior ◽  
Measurement Data ◽  
Data Set ◽  
Water Vapor Radiometer ◽  
Long Term Observation ◽  
Scientific Value ◽  
High Degree

Abstract. A mesospheric water vapor data set obtained by the middle atmospheric water vapor radiometer (MIAWARA) close to Bern, Switzerland (46.88∘ N, 7.46∘ E) during October 2010 to September 2017 is investigated to study the long-term evolution and variability of quasi 2-day waves (Q2DWs). We present a climatological overview and an insight on the dynamical behavior of these waves with the occurring spectrum of periods as seen from a midlatitude observation site. Such a large and nearly continuous measurement data set as ours is rare and of high scientific value. The core results of our investigation indicate that the activity of the Q2DW manifests in burst-like events and is higher during winter months (November–February) than during summer months (May–August) for the altitude region of the mesosphere (up to 0.02 hPa in winter and up to 0.05 hPa in summer) accessible for the instrument. Single Q2DW events reach at most about 0.8 ppm in the H2O amplitudes. Further, monthly mean Q2DW amplitude spectra are presented and reveal a high-frequency variability between different months. A large fraction of identified Q2DW events (20 %) develop periods between 38 and 40 h. Further, we show the temporal evolution of monthly mean Q2DW oscillations continuously for all months and separated for single months over 7 years. The analysis of autobicoherence spectra gives evidence that Q2DWs are sometimes phase coupled to diurnal oscillations to a high degree and to waves with a period close to 18 h.

scholarly journals Analysis of Stable Targets in High-Resolution Polarimetric SAR Data Stacks

2016 ◽  
Vol 7 (1) ◽  
pp. 10-19 ◽  
Author(s):  
B. Scheuchl
Keyword(s):  
Decomposition Analysis ◽  
Polarimetric Sar ◽  
Data Set ◽  
Full Resolution ◽  
Novel Approach ◽  
Complexity Result ◽  
Degree Of Confidence ◽  
Distributed Target ◽  
Sar Data ◽  
High Degree

Polarimetric SAR data provide information about the scattering of the area observed. The availability of data stacks allows the identification of stable targets and subsequent scattering analysis with a high degree of confidence at full resolution. A novel approach to find and evaluate polarimetric persistent target is presented, that is an extension of well-established analysis methods for single scenes. The use of the Cloude-Pottier distributed target decomposition analysis applied on the temporal averages (as opposed to spatial averaging), combined with a Cameron point target analysis applied on each layer separately to select pixels only, provides an efficient scattering classification of polarimetric persistent point targets in the stack. This method can also be used to analyze targets identified through other means, albeit at a lower degree of confidence. The approach retains the full resolution of the data set, though temporal changes between acquisitions add additional complexity. Result interpretation is therefore performed under consideration of a set of boundary conditions. Results from the analysis of two polarimetric data stacks acquired by RADARSAT-2 are shown.

The Radioactivity Depth Analysis Tool (RADPAT)

2009 ◽  
Author(s):  
B. Alan Shippen ◽  
Malcolm J. Joyce
Keyword(s):  
Silica Sand ◽  
Model Parameters ◽  
Analysis Tool ◽  
Data Set ◽  
Plant Materials ◽  
Depth Analysis ◽  
Absolute Efficiency ◽  
The Uk ◽  
High Degree ◽  
Detector Type

The Radioactive Depth Analysis Tool (RADPAT) is a PhD bursary project currently being undertaken at Lancaster University in the UK. The RADPAT project involves the development of nuclear instrumentation capable of ascertaining depth of radioactive contamination within legacy plant materials such as concrete. This paper evaluates the merits of two types of detector; sodium iodide (NaI(Tl)) and cadmium zinc telluride (CZT), both of which have been identified as possible solutions for the final RADPAT detector. A bespoke concrete phantom has been developed to allow a set depth of simulated contamination to be obtained with a low measurement error within a concrete analogue: silica sand. Utilising this phantom, in combination with the selected detectors, a set of measurements have been obtained varied with increasing depth of caesium-137 contamination. By comparing the relative attenuation of the x-ray and γ-ray photo-peaks from the data-set to that suggested by a differential attenuation law, a set of model parameters can be obtained. This model, once calibrated, describes the contact depth of contamination with the relative intensity of the peaks in a measured spectrum with a high degree of accuracy. Thus, this technique allows for a set of measurements across the surface of a given material to obtain the inherent distribution of the depth of caesium-137 contamination. This paper is primarily interested in the ability of each detector type to derive the attenuation model, paying particular attention to the associated statistical uncertainty of the fitted parameters and thus the error in the derived depth. The paper describes the contributing effects of the inherent properties of each detector; effects such as their energy resolution, absolute efficiency as well as peak-to-Compton ratio. Finally a commentary on the applicability of each selected detector type is presented, including a comment on the extension the technique to a more generic, real world solution.

Are standard wastewater treatment plant design methods suitable for any municipal wastewater?

2012 ◽  
Vol 66 (2) ◽  
pp. 328-335 ◽  
Author(s):  
G. Insel ◽  
B. Güder ◽  
G. Güneş ◽  
E. Ubay Cokgor
Keyword(s):  
Activated Sludge ◽  
Volatile Fatty Acids ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Design Methods ◽  
Biological Nutrient Removal ◽  
Model Parameters ◽  
Plant Design ◽  
Biological Phosphorus Removal ◽  
Operational Parameters

The design and operational parameters of an activated sludge system were analyzed treating the municipal wastewaters in Istanbul. The design methods of ATV131, Metcalf & Eddy together with model simulations were compared with actual plant operational data. The activated sludge model parameters were determined using 3-month dynamic data for the biological nutrient removal plant. The ATV131 method yielded closer sludge production, total oxygen requirement and effluent nitrogen levels to the real plant after adopting correct influent chemical oxygen demand (COD) fractionation. The enhanced biological phosphorus removal (EBPR) could not easily be predicted with ATV131 method due to low volatile fatty acids (VFA) potential.

scholarly journals Long-term observation of mid-latitude quasi 2-day waves by a water vapor radiometer

2018 ◽  
Author(s):  
Martin Lainer ◽  
Klemens Hocke ◽  
Niklaus Kämpfer
Keyword(s):  
Water Vapor ◽  
Large Fraction ◽  
Dynamical Behavior ◽  
Measurement Data ◽  
Data Set ◽  
Water Vapor Radiometer ◽  
Long Term Observation ◽  
Scientific Value ◽  
High Degree

Abstract. A mesospheric water vapor data set obtained by the middle atmospheric water vapor radiometer (MIAWARA) close to Bern, Switzerland (46.88° N, 7.46° E) during October 2010 to September 2017 is investigated to study the long-term evolution and variability of quasi 2-day waves (Q2DWs). We present a climatological overview and an insight on the dynamical behavior of these waves with the occurring spectrum of periods as seen from a mid-latitude observation site. Such a large and nearly continuous measurement data set as ours is rare and of high scientific value. The core results of our investigation include that the activity of the Q2DW manifests in burst-like events and is higher during winter months (November–February) than during summer months (May–August) for the altitude region of the mesosphere (up to 0.02 hPa in winter and up to 0.05 hPa in summer) that is accessible for the instrument. Single Q2DW events reach at most about 0.8 ppm in the H2O amplitudes. Further, monthly mean Q2DW amplitude spectra are presented and reveal a high frequency variability between different months. A large fraction of identified Q2DW events (20 %) develop periods between 38–40 h. Further, we show the temporal evolution of monthly mean Q2DW oscillations continuously for all months and separated for single months over 7 years. The analysis of autobicoherence spectra gives evidence that the Q2DW occasionally is to a high degree phase coupled to diurnal oscillations and to waves with a period close to 18 h.

Use of genetic markers to aid in re-establishing migratory connectivity in a fragmented metapopulation of bull trout (Salvelinus confluentus)

2011 ◽  
Vol 68 (11) ◽  
pp. 1952-1969 ◽  
Author(s):  
Patrick W. DeHaan ◽  
Shana R. Bernall ◽  
Joseph M. DosSantos ◽  
Lawrence L. Lockard ◽  
William R. Ardren
Keyword(s):  
River System ◽  
Fish Passage ◽  
Bull Trout ◽  
Region Of Origin ◽  
Salvelinus Confluentus ◽  
Data Set ◽  
Degree Of Confidence ◽  
High Degree ◽  
Spawning Tributaries ◽  
Analysis Protocol

Dams and other barriers fragment important migratory corridors for bull trout ( Salvelinus confluentus ) across the species range. Three dams constructed without fish passage facilities prevented migratory bull trout in the Lake Pend Oreille and Clark Fork River system in Idaho and Montana, USA, from returning to their natal spawning tributaries for nearly 100 years. We genotyped bull trout from 39 spawning tributaries to assemble a baseline data set that we used to develop a real-time genotyping and analysis protocol to assist with upstream fish transport decisions. Self-assignment tests and analysis of blind samples indicated that unknown individuals could be assigned to their region of origin with a high degree of confidence. From 2004 to 2010, genetic assignments were conducted for 259 adult bull trout collected below mainstem dams. Based on genetic assignments, 203 fish were transported upstream above one or more dams. This protocol has helped re-establish connectivity in a fragmented system, providing increased numbers of spawning adults for numerically depressed populations above the dams. We discuss the utility of genetic data for assisting with upstream passage decisions.

Managing sewer solids for the reduction of foul flush effects – Forfar WTP

2002 ◽  
Vol 45 (3) ◽  
pp. 265-272
Author(s):  
A.G. Fraser ◽  
R. Sakrabani ◽  
R.M. Ashley ◽  
F.M. Johnstone
Keyword(s):  
Sediment Quality ◽  
Treatment Plant ◽  
Sediment Traps ◽  
Bulk Water ◽  
The Body ◽  
Flow Conditions ◽  
Sediment Deposits ◽  
Hydraulic Regime ◽  
High Degree

In times of high sewer flow, conditions can exist which enable previously deposited material to be re-entrained back into the body of the flow column. Pulses of this highly polluted flow have been recorded in many instances at the recently constructed wastewater treatment plant (WTP) in Forfar, Scotland. Investigations have been undertaken to characterise the incoming flows and to suggest remedial measures to manage the quality fluctuations. Initial visits to the works and incoming pipes indicated a high degree of sediment deposition in the two inlet pipes. Analyses were carried out and consequently, changes to the hydraulic regime were made. Measurements of sediment level, sediment quality, wall slime and bulk water quality were monitored in the period following the remedial works to observe any improvements. Dramatic alterations in each of the determinands measured were recorded. Analyses were then undertaken to determine long term sediment behaviour and to assess the future usefulness of existing upstream sediment traps. It was concluded that with proper maintenance of the traps, the new hydraulic regime is sufficient to prevent further significant build up of sediment deposits and reduce impacts on the WTP. Further investigations made by North of Scotland Water Authority highlighted trade inputs to the system which may also have contributed to the now managed foul flush problem.

EXPONENTIATED HALF-LOGISTIC LOMAX DISTRIBUTION WITH PROPERTIES AND APPLICATION

2019 ◽  
Vol XVI (2) ◽  
pp. 1-11
Author(s):  
Farrukh Jamal ◽  
Hesham Mohammed Reyad ◽  
Soha Othman Ahmed ◽  
Muhammad Akbar Ali Shah ◽  
Emrah Altun
Keyword(s):  
Real Data ◽  
Continuous Model ◽  
Model Parameters ◽  
Data Set ◽  
Lomax Distribution ◽  
Mathematical Properties ◽  
Proposed Model ◽  
Probability Weighted Moment ◽  
Record Statistics ◽  
Maximum Likelihood Criterion

A new three-parameter continuous model called the exponentiated half-logistic Lomax distribution is introduced in this paper. Basic mathematical properties for the proposed model were investigated which include raw and incomplete moments, skewness, kurtosis, generating functions, Rényi entropy, Lorenz, Bonferroni and Zenga curves, probability weighted moment, stress strength model, order statistics, and record statistics. The model parameters were estimated by using the maximum likelihood criterion and the behaviours of these estimates were examined by conducting a simulation study. The applicability of the new model is illustrated by applying it on a real data set.

Sludge minimization by disintegration at different wastewater treatment plants

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
New Technologies ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Biological Degradation ◽  
Ongoing Research ◽  
Sludge Minimization

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).

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