Analysis of Techniques for Evaluating and Optimizing Existing Full-Scale Wastewater Treatment Plants

1992 ◽  
Vol 25 (4-5) ◽  
pp. 103-118 ◽  
Author(s):  
G. T. Daigger ◽  
J. A. Buttz ◽  
J. P. Stephenson

This paper presents an analysis of techniques applied to the evaluation and optimization of nearly 40 full-scale wastewater treatment plants. The techniques evaluated included oxygen transfer analysis by off-gas and hydrogen peroxide techniques, clarifier analysis by stress testing and hydraulic analysis, on-line monitoring, and reactor tracer testing. The results indicate that the process performance of full-scale wastewater treatment units can be measured using these techniques. Advantages exist for off-gas testing when applied to the analysis of low to moderate turbulence diffused air systems. Hydrogen peroxide analysis can be applied to essentially all oxygen transfer systems. Stress testing can be used to quantify the treatment capability of clarifier units; hydraulic analysis can then be used to identify clarifier upgrade opportunities and to quantify the impact of any modifications implemented. On-line monitoring is the most powerful technique tested. It has been used successfully to optimize and improve full-scale treatment plants. Reactor tracer testing can be used to identify upgrade opportunities for full-scale units.

1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete

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.


Water SA ◽  
2021 ◽  
Vol 47 (1 January) ◽  
Author(s):  
Olivier Nsengiyumva ◽  
Yuva Coothen ◽  
David Ikumi ◽  
Kirshen Naidoo

There have been three considerable shifts, in the past 20 years, in the conventional design and modelling of wastewater treatment plants (WWTPs): (i) single unit process to plant-wide modelling, (ii) consideration of WWTPs as water and resource recovery facilities (WRRFs), and (iii) the need to simplify WWTP models to allow their intake by new stakeholders (i.e. plant operators, designers and decision-makers) who use these models for evaluation of WWTP optimisation strategies. The latter shift has prompted the debate about model complexity versus the required modelling purpose among modellers. In addition to the aforementioned shifts, there has been limited research on the impact of sludge recycling dewatering liquor on the overall plant performance, especially in the context of South African WWTPs. A simplified full-scale steady-state WWTP simulation tool was developed, based on principles of sound mass-balance stoichiometry and rate-limiting kinetics. This tool enables the user to analyse the impact of recycling the DWL on the plant performance through different scenarios. The strategic scenarios evaluated included the implementation of two side-stream treatment processes (STPs), namely BABE and struvite precipitation. The evaluation of various strategies was done using the benchmark simulation model (BSM) task group plant performance indices (i.e. effluent quality and operational cost indices, EQI and OCI, respectively) incorporated into the simplified steady-state full-scale models. The integration of STP in the WWTP layout results in better EQI and OCI. The composition of the DWL affects the choice of the STP to be used, i.e., for DWL from an AD treating WAS that is not P-rich the recommended side-stream treatment operation would be the BABE process rather than struvite precipitation.


2010 ◽  
Vol 2 (5) ◽  
pp. 97-102
Author(s):  
Ala Sokolova ◽  
Mindaugas Rimeika

The paper analyzes the impact of the way of mounting a tube diffuser, the design of an aeration tank and the presence of a fixed carrier on the operational parameters of aeration systems used in small wastewater treatment plants. It was found out that the vertically mounted tube diffuser decreased standard oxygen transfer rate (SOTR) of the aeration system by approximately 20% and standard oxygen transfer efficiency (SOTE) by 25% comparing to the horizontally mounted tube diffuser. It was also defined that the design of the aeration tank might have an impact on the operation parameters of the aeration system: when the centre shell used to protect a diffuser was dismantled from a test tank, SOTR and SOTE increased by approximately 20%. It was also established that the presence of the fixed carrier in the aeration tank did not have an impact on the performance of aeration systems. Finally, research was carried out to compare the operational parameters of two diffusers of different types offered on the market and used in small wastewater treatment plants. It was found out that the performance different type diffusers might vary considerably.


2006 ◽  
Vol 53 (4-5) ◽  
pp. 215-223 ◽  
Author(s):  
M. Devisscher ◽  
G. Ciacci ◽  
L. Fé ◽  
L. Benedetti ◽  
D. Bixio ◽  
...  

This paper discusses a methodology to estimate the costs and benefits of advanced control for wastewater treatment plants. The methodology has been applied to four wastewater treatment plants, representing four standard types of plants built in Flanders, Belgium. The paper outlines the methodology and illustrated results from one of the four design cases. General results are shown and contrasted with full-scale experience. The methodology appears to give realistic results and will be used for further refinement of default control algorithms for certain types of plants. A preliminary analysis indicates that on-line control can become cost-effective for plant sizes above 50,000 population equivalents.


1995 ◽  
Vol 31 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Jacob Carstensen ◽  
Poul Harremoës ◽  
Henrik Madsen

Time series analysis of on-line monitored ammonia and nitrate concentrations from full-scale wastewater treatment plants operated according to an alternating scheme makes the identification of Monod-kinetic expressions possible. The models presented in the present context only include kinetic parameters which have shown to be significant in a statistical sense. Estimates of kinetic parameters for the nitrification and denitrification processes are obtained by applying these models to the time series of ammonia and nitrate concentrations. In this paper, the concept of statistical identification which depends on the two conditions of theoretical and practical identification, is described. Experiences from estimating time series models of the nitrification and denitrification processes with data from two wastewater treatment plants are discussed. It appears that the dynamic of the biological processes on a full-scale plant is strongly varying. The proposed models are suitable for on-line control, because the states of the plant are continuously updated as new information from the on-line sensors becomes available.


1999 ◽  
Vol 39 (4) ◽  
pp. 103-111 ◽  
Author(s):  
Frank Obenaus ◽  
Karl-Heinz Rosenwinkel ◽  
Jens Alex ◽  
Ralf Tschepetzki ◽  
Ulrich Jumar

This report presents the main components of a system for the model-based control of aerobic biological wastewater treatment plants. The crucial component is a model which is linked to the actual processes via several interfaces and which contains a unit which can immediately follow up the current process state. The simulation calculation of the model is based on data which are yielded by on-line measuring devices. If the sensors should fail at times, there are available a number of alternative concepts, some of which are based on the calculations of artificial neural networks or linear methods.


1997 ◽  
Vol 36 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Vibeke R. Borregaard

In the upgrade of wastewater treatment plants to include biological nutrient removal the space available is often a limiting facor. It may be difficult to use conventional suspended growth processes (i.e. activated sludge) owing to the relatively large surface area required for these processes. Recent years have therefore seen a revived interest in treatment technologies using various types of attached growth processes. The “new” attached growth processes, like the Biostyr process, utilise various kinds of manufactured media, e.g. polystyrene granules, which offer a high specific surface area, and are therefore very compact. The Biostyr plants allow a combination of nitrification-denitrification and filtration in one and the same unit. The results obtained are 8 mg total N/l and an SS content normally below 10 mg/l. The plants in Denmark which have been extended with a Biostyr unit have various levels of PLC control and on-line instrumentation.


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