Future Directions in Instrumentation, Control and Automation in the Water and Wastewater Industry

1993 ◽  
Vol 28 (11-12) ◽  
pp. 9-14 ◽  
Author(s):  
Troy D. Vassos
Keyword(s):  
Control Strategies ◽  
Treatment Plant ◽  
Dynamic Modelling ◽  
Simulation Software ◽  
Plant Performance ◽  
Limiting Factors ◽  
Time Data ◽  
Training Environment ◽  
Factors Affecting ◽  
Water And Wastewater

The need to optimize treatment plant performance and to meet increasingly stringent effluent criteria are two key factors affecting future development of instrumentation, control and automation (ICA) applications in the water and wastewater industry. Two case studies are presented which highlight the need for dynamic modelling and simulation software to assist operations staff in developing effective instrumentation control strategies, and to provide a training environment for the evaluation of such strategies. One of the limiting factors to date in realizing the potential benefits of ICA has been the inability to adequately interpret the large number of existing instrumentation inputs available at treatment facilities. The number of inputs can exceed the number of control loops by up to three orders of magnitude. The integration of dynamic modelling and expert system software is seen to facilitate the interpretation of real-time data, allowing both quantitative (instrumented) and qualitative (operator input) information to be integrated for process control. Improvements in sensor reliability and performance, and the development of biological monitoring sensors and control algorithms are also discussed.

Dynamic optimisation of WWTP inflow to reduce total emission

2007 ◽  
Vol 56 (10) ◽  
pp. 11-18 ◽  
Author(s):  
J. Tränckner ◽  
T. Franz ◽  
K. Seggelke ◽  
P. Krebs
Keyword(s):  
Control Strategies ◽  
Integrated Control ◽  
Treatment Plant ◽  
Limiting Factors ◽  
Current Status ◽  
Nutrient Loads ◽  
Dynamic Optimisation ◽  
Online Measurements ◽  
Modelling Studies

A prerequisite for an integrated control of sewer and wastewater treatment plant (WWTP) is a capacity driven inflow control to WWTP. This requires reliable information about the current status of WWTP operation and its behaviour on varying hydraulic, COD and nutrient loads. So far most of the proposed control strategies are based on hypothetical modelling studies. In this paper the behaviour of three large WWTPs on increased storm water loads is analysed based on online measurements of several years. In all cases the main limiting factors for an increase of load were the sedimentation processes in the secondary clarifier and the nitrification capacity. In one case study predictive control strategies have been developed observing these processes which are backboned by effluent control. Tests using an integrated model of sewer and WWTP demonstrate that inflow control on emission load varies significantly with rain intensity.

A methodology to evaluate water and wastewater treatment plant reliability

2001 ◽  
Vol 43 (10) ◽  
pp. 91-99 ◽  
Author(s):  
D. Eisenberg ◽  
J. Soller ◽  
R. Sakaji ◽  
A. Olivieri
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Reuse ◽  
Treatment Plant ◽  
Plant Performance ◽  
Water And Wastewater Treatment ◽  
Risk Manager ◽  
Straightforward Method ◽  
Recent Developments ◽  
Treatment Facilities ◽  
Water And Wastewater

Evaluating the reliability of treatment processes and treatment facilities should be an important part of the planning and design process for water resource, wastewater treatment, and particularly wastewater reuse projects. With the recent developments in technology, particularly the development of membrane processes and alternative disinfection processes for water and wastewater treatment, there is an increasing need for a common methodology to evaluate the reliability of alternative processes and treatment facilities that utilize different combinations of those processes. To assess the reliability of a treatment facility, several aspects of treatment must be considered including a methodical evaluation of both mechanical reliability and plant performance. A straightforward method for conducting these types of analyses is described herein along with a description of applications of this methodology. A discussion is provided highlighting the value of such a methodology for both the water quality engineer and the risk manager.

Strategy for nutrient control in modern effluent treatment plants

2007 ◽  
Vol 55 (6) ◽  
pp. 157-163 ◽  
Author(s):  
Å. Sivard ◽  
T. Ericsson ◽  
B. Larsson
Keyword(s):  
New Technologies ◽  
Treatment Plant ◽  
Pulp And Paper ◽  
Effluent Treatment ◽  
Plant Performance ◽  
Nitrogen And Phosphorus ◽  
Factors Affecting ◽  
Conventional Activated Sludge ◽  
Key Factor ◽  
Pulp And Paper Effluent

The fate of nutrients in the modern effluent treatment plant depends on several factors, for example type of treatment plant, availability of nutrients in the specific effluent, dosing of nutrients and sludge age/production. New technologies with the aim to increase the efficiency and stability of the conventional activated sludge process have strongly affected the possibilities to control discharge of nutrients in pulp and paper effluents. A paradox is that a reduction of organic material may often lead to an increase of nutrient discharges. It is of the utmost importance that the operators have good knowledge of the factors affecting nutrient uptake and release in order to minimise nutrient discharge and obtain optimal plant performance. Dosing of nitrogen and phosphorus is one key factor in the sensitive balance in most pulp and paper effluent treatment plants. Correct dosing is crucial as high or low doses might lead not only to increased discharge of nutrients but also to severe operational problems with poor sludge quality, which in turn affects the plant performance for longer periods.

Approach to the Reforms in Nightsoil Treatment Process Introduced Abroad

1991 ◽  
Vol 24 (5) ◽  
pp. 189-196 ◽  
Author(s):  
S. B. Guo ◽  
R. Z. Chen ◽  
G. Li ◽  
H. Y. Shoichi
Keyword(s):  
Treatment Cost ◽  
Treatment Process ◽  
Biological Process ◽  
Treatment Plant ◽  
Plant Performance ◽  
First Year ◽  
Original Design ◽  
Effluent Quality ◽  
Public Toilets

In 1987 Guangzhou Liede Nightsoil Treatment Plant started commissioning. The purpose of the plant is to dispose of 400 tons of nightsoi1 from city public toilets per day. In the first year of the commissioning a biological process was basically used according to the original design made by a Danish company. Practically it has been proved that the design is effective. The process can reduce BOD from 3800 mg/l to about 133 mg/l, or by approximately 96.5 percent. The performance of the sludge digester system is satisfactory. Because the primary investigation on characteristics of the nightsoil was insufficient there were some problems raised during the commissioning. So in the first year the effluent failed to achieve the desired quality. After the analysis of the plant performance some necessary reforms have been carried out. Now the effluent quality can stably meet the national discharge limits and the treatment cost decreases.

Use of chemical upgrading (CU) in Hungary and Slovakia

1994 ◽  
Vol 30 (5) ◽  
pp. 87-95 ◽  
Author(s):  
Susan E. Murcott ◽  
Donald R. F. Harleman
Keyword(s):  
Wastewater Treatment ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Domestic Sewage ◽  
Metal Salts ◽  
Plant Performance ◽  
Eastern European ◽  
Low Doses ◽  
The Past ◽  
Treatment Technologies

In the past decade, the development of polymers and new chemical technologies has opened the way to using low doses of chemicals in wastewater treatment. “Chemical upgrading” (CU) is defined in this paper as an application of these chemical technologies to upgrade overloaded treatment systems (typically consisting of conventional primary plus biological treatment) in Central and Eastern European (CEE) countries. Although some of the chemical treatment technologies are proven ones in North America, Scandinavia, and Germany, a host of factors, for example, the variations in composition and degree of pollution, the type of technologies in use, the type and mix of industrial and domestic sewage, and the amount of surface water, had meant that the viability of using CU in CEE countries was unknown. This report describes the first jar tests of CU conducted during the summer of 1993. The experiments show CU's ability to improve wastewater treatment plant performance and to potentially assist in the significant problem of overloaded treatment plants. Increased removal of BOD, TSS, and P in the primary stage of treatment is obtained at overflow rates above 1.5 m/h, using reasonably priced, local sources of metal salts in concentrations of 25 to 50 mg/l without polymers.

Impacts of separate rejection water treatment on the overall plant performance

2003 ◽  
Vol 48 (4) ◽  
pp. 139-146 ◽  
Author(s):  
B. Wett ◽  
J. Alex
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Operating Experience ◽  
Plant Performance ◽  
High Tech ◽  
State Variables ◽  
Total N ◽  
Unit Process ◽  
Innovative Tool ◽  
The Impact

A separate rejection water treatment appears as a high-tech unit process which might be recommendable only for specific cases of an upgrading of an existing wastewater treatment plant. It is not the issue of this paper to consider a specific separate treatment process itself but to investigate the influence of such a process on the overall plant performance. A plant-wide model has been applied as an innovative tool to evaluate effects of the implemented sidestream strategy on the mainstream treatment. The model has been developed in the SIMBA environment and combines acknowledged mathematical descriptions of the activated sludge process (ASM1) and the anaerobic mesophilic digestion (Siegrist model). The model's calibration and validation was based on data from 5 years of operating experience of a full-scale rejection water treatment. The impact on the total N-elimination efficiency is demonstrated by detailed nitrogen mass flow schemes including the interactions between the wastewater and the sludge lane. Additionally limiting conditions due to dynamic N-return loads are displayed by the model's state variables.

scholarly journals Industrial Control under Non-Ideal Measurements: Data-Based Signal Processing as an Alternative to Controller Retuning

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1237
Author(s):  
Ivan Pisa ◽  
Antoni Morell ◽  
Ramón Vilanova ◽  
Jose Lopez Vicario
Keyword(s):  
Mean Squared Error ◽  
Control Strategies ◽  
Treatment Plant ◽  
Industrial Control ◽  
Output Data ◽  
Complex Processes ◽  
Squared Error ◽  
Complex Design ◽  
Solution Design ◽  
Delay Correction

Industrial environments are characterised by the non-lineal and highly complex processes they perform. Different control strategies are considered to assure that these processes are correctly performed. Nevertheless, these strategies are sensible to noise-corrupted and delayed measurements. For that reason, denoising techniques and delay correction methodologies should be considered but, most of these techniques require a complex design and optimisation process as a function of the scenario where they are applied. To alleviate this, a complete data-based approach devoted to denoising and correcting the delay of measurements is proposed here with a two-fold objective: simplify the solution design process and achieve its decoupling from the considered control strategy as well as from the scenario. Here it corresponds to a Wastewater Treatment Plant (WWTP). However, the proposed solution can be adopted at any industrial environment since neither an optimization nor a design focused on the scenario is required, only pairs of input and output data. Results show that a minimum Root Mean Squared Error (RMSE) improvement of a 63.87% is achieved when the new proposed data-based denoising approach is considered. In addition, the whole system performance show that similar and even better results are obtained when compared to scenario-optimised methodologies.

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