Investigations of the dynamic behaviour of the composition of combined sewage using on-line analyzers

2002 ◽  
Vol 45 (4-5) ◽  
pp. 77-83 ◽  
Author(s):  
H. Grüning ◽  
H. Orth
Keyword(s):  
Dynamic Behaviour ◽  
Scattered Light ◽  
Treatment Plant ◽  
Storm Water ◽  
Behaviour Pattern ◽  
Physical Parameters ◽  
Water Tank ◽  
Real Time Control ◽  
Term Operation ◽  
On Line

Continuously analyzing sensors today permit the recording of the dynamic behaviour pattern of pollutants in combined sewage through physical parameters. This report presents the results of such measurements. They were done in a storm water tank which is equipped with a combined sewage overflow and located at the end of a 360 ha catchment area. The results show that by using a combination of sensors for dissolved solids (using UV absorption) and of sensors for particulate solids (using scattered light measurement), reliable information on the composition of the combined sewage can be obtained. A statistical relationship between these two parameters and the chemical oxygen demand was established. The analyzing methods presented permit the real-time control of sewer systems on the basis of the pollution carried in the combined sewage. Through the information on the actual concentration of primary pollutants provided by on-line analysis, heavily polluted streams can be retained selectively in storm water tanks or directed to the treatment plant. However, due to the adverse conditions in a sewer system operational disturbances and stringent maintenance requirements are still an impediment to long-term operation.

scholarly journals A real-time control strategy for separation of highly polluted storm water based on UV–Vis online measurements – from theory to operation

2011 ◽  
Vol 63 (10) ◽  
pp. 2287-2293 ◽  
Author(s):  
H. Hoppe ◽  
S. Messmann ◽  
A. Giga ◽  
H. Gruening
Keyword(s):  
Real Time ◽  
Stream Water ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Storm Water ◽  
Water Runoff ◽  
Real Time Control ◽  
Flow Measurements ◽  
Time Control ◽  
Storm Water Runoff

‘Classical’ real-time control (RTC) strategies in sewer systems are based on water level and flow measurements with the goal of activation of retention volume. The control system rule of ‘clean (storm water) runoff into the receiving water – polluted runoff into the treatment plant’ has been thwarted by rough operating conditions and lack of measurements. Due to the specific boundary conditions in the city of Wuppertal's separate sewer system (clean stream water is mixed with polluted storm water runoff) a more sophisticated – pollution-based – approach was needed. In addition the requirements to be met by the treatment of storm water runoff have become more stringent in recent years. To separate the highly-polluted storm water runoff during rain events from the cleaner stream flow a pollution-based real-time control (P-RTC) system was developed and installed. This paper describes the measurement and P-RTC equipment, the definition of total suspended solids as the pollution-indicating parameter, the serviceability of the system, and also gives a cost assessment. A sensitivity analysis and pollution load calculations have been carried out in order to improve the P-RTC algorithm. An examination of actual measurements clearly shows the ecological and economic advantages of the P-RTC strategy.

Experiences with on-line measurements at a wastewater treatment plant for extended nitrogen removal

1996 ◽  
Vol 33 (1) ◽  
pp. 175-182 ◽  
Author(s):  
U. Nyberg ◽  
B. Andersson ◽  
H. Aspegren
Keyword(s):  
Suspended Solids ◽  
Treatment Plant ◽  
Storm Water ◽  
Secondary Effluent ◽  
Secondary Treatment ◽  
Short Term ◽  
Line Measurement ◽  
On Line ◽  
Term Performance ◽  
Raw Wastewater

On-line sensors have been used at the Klagshamn treatment plant to measure the concentration of suspended solids in the raw wastewater, in the primary effluent and in the secondary effluent. By means of the sensors the short-term performance of the primary and the secondary treatment have been evaluated. The sensors are important when the total discharges of pollutants from the plant are to be considered during storm water events. Parallel on-line measurements and laboratory analyses of grab samples have shown that the used sensor type, based on NIR technique, reflects the concentrations rather well. The on-line measurement in the raw wastewater is rather unreliable due to clogging which means that using this application for control can be questioned.

On-line nitrification inhibition monitoring using immobilised bacteria

1998 ◽  
Vol 37 (12) ◽  
pp. 193-196 ◽  
Author(s):  
E. Hayes ◽  
J. Upton ◽  
R. Batts ◽  
S. Pickin
Keyword(s):  
Treatment Plant ◽  
Test Method ◽  
Effluent Treatment ◽  
Nitrifying Bacteria ◽  
Continuous Measure ◽  
Nitrification Inhibition ◽  
Real Time Control ◽  
Time Control ◽  
Effluent Treatment Plant ◽  
On Line

As wastewater treatment plant managers are required to meet increasingly stringent standards the focus on processes has shifted more and more towards assessing the treatability of a waste. Many substances discharged to effluent treatment plants may inhibit the process of nitrification. Traditional testing methods are costly and cannot be used for real time control which has led to the development of the AmtoxTM system. AmtoxTM uses a culture of immobilised nitrifying bacteria in a system maintained at 30°C. This enhances the rate of nitrification and gives an early warning of toxicity. This paper presents data comparing Amtox with the conventional nitrification inhibition test method and describes the instrument designed for laboratory use. Preliminary data for the on-line Amtox system are also included: these data provide the first, direct, continuous measure of nitrification inhibition on an effluent treatment plant.

The Importance of Rainfall Distribution in Urban Drainage Operation

1992 ◽  
Vol 23 (2) ◽  
pp. 121-136 ◽  
Author(s):  
Fons Nelen ◽  
Annemarieke Mooijman ◽  
Per Jacobsen
Keyword(s):  
Real Time ◽  
Treatment Plant ◽  
Rain Gauge ◽  
Point Of View ◽  
Rain Event ◽  
Real Time Control ◽  
Rainfall Distribution ◽  
Statistical Point ◽  
Time Control ◽  
Spatially Distributed

A control simulation model, called LOCUS, is used to investigate the effects of spatially distributed rain and the possibilities to benefit from this phenomenon by means of real time control. The study is undertaken for a catchment in Copenhagen, where rainfall is measured with a network of 8 rain gauges. Simulation of a single rain event, which is assumed to be homogeneous, i.e. using one rain gauge for the whole catchment, leads to large over- and underestimates of the systems output variables. Therefore, when analyzing a single event the highest possible degree of rainfall information may be desired. Time-series simulations are performed for both an uncontrolled and a controlled system. It is shown that from a statistical point of view, rainfall distribution is NOT significant concerning the probability of occurrence of an overflow. The main contributing factor to the potential of real time control, concerning minimizing overflows, is to be found in the system itself, i.e. the distribution of available storage and discharge capacity. When other operational objectives are involved, e.g., to minimize peak flows to the treatment plant, rainfall distribution may be an important factor.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

Long-Term Simulation of Pollutant Loads in Treatment Plant Effluents and Combined Sewer Overflows

1990 ◽  
Vol 22 (10-11) ◽  
pp. 69-76 ◽  
Author(s):  
A. Durchschlag
Keyword(s):  
Waste Water Treatment ◽  
Treatment Plant ◽  
Storm Water ◽  
Water Runoff ◽  
Storage Tanks ◽  
Combined Sewer Overflows ◽  
Storm Water Runoff ◽  
Combined Sewer ◽  
Hydraulic Load ◽  
Water Tanks

As a result of urbanization, the pollutant discharges from sources such as treatment plant effluents and polluted stormwaters are responsible for an unacceptable water quality in the receiving waters.In particular, combined sewer system overflows may produce great damage due to a shock effect. To reduce these combined sewer overflow discharges, the most frequently used method is to build stormwater storage tanks. During storm water runoff, the hydraulic load of waste water treatment plants increases with additional retention storage. This might decrease the treatment efficiency and thereby decrease the benefit of stormwater storage tanks. The dynamic dependence between transport, storage and treatment is usually not taken into account. This dependence must be accounted for when planning treatment plants and calculating storage capacities in order to minimize the total pollution load to the receiving waters. A numerical model will be described that enables the BOD discharges to be continuously calculated. The pollutant transport process within the networks and the purification process within the treatment plants are simulated. The results of the simulation illustrate; a statistical balance of the efficiency of stormwater tanks with the treatment plant capacity and to optimize the volume of storm water tanks and the operation of combined sewer systems and treatment plants.

Optimising the Efficiency of Storm Water Settling Basins by Means of Bypassing

1993 ◽  
Vol 27 (5-6) ◽  
pp. 105-110 ◽  
Author(s):  
F. H. L. R. Clemens ◽  
H. J. van Mameren ◽  
J. Kollen
Keyword(s):  
Boundary Conditions ◽  
Dynamic Behaviour ◽  
Storm Water ◽  
Mixed System ◽  
Research Needs ◽  
Settling Basin ◽  
Potential Increase ◽  
Overall Efficiency ◽  
Further Development

The reduction in pollutional load realised by storm water settling basins is potentially reduced due to the occurrence of a partially mixed situation in the basin or due to resuspension of settled material. The decrease in efficiency can theoretically be avoided by means of partially bypassing the basin. In order to quantify the potential increase in efficiency a settling basin in Amersfoort is taken as an example. This basin seems to behave like an almost completely mixed system, bypassing would increase the overall efficiency from ca. 34 % to ca 39 % for three overflows. The dynamic behaviour of settling basins, scouring conditions and the boundary conditions for which settling basins are to be designed are the research needs for further development in the field of storm water settling basins.

Modifications of rainfall runoff and decision finding models for on-line simulation in real time control

1999 ◽  
Vol 39 (9) ◽  
pp. 201-207
Author(s):  
Andreas Cassar ◽  
Hans-Reinhard Verworn
Keyword(s):  
Real Time ◽  
Urban Drainage ◽  
Rain Event ◽  
Rainfall Runoff ◽  
Real Time Control ◽  
Design Storm ◽  
Time Control ◽  
Timing Data ◽  
On Line ◽  
Rainfall Runoff Model

Most of the existing rainfall runoff models for urban drainage systems have been designed for off-line calculations. With a design storm or a historical rain event and the model system the rainfall runoff processes are simulated, the faster the better. Since very recently, hydrodynamic models have been considered to be much too slow for real time applications. However, with the computing power of today - and even more so of tomorrow - very complex and detailed models may be run on-line and in real time. While the algorithms basically remain the same as for off-line simulations, problems concerning timing, data management and inter process communication have to be identified and solved. This paper describes the upgrading of the existing hydrodynamic rainfall runoff model HYSTEM/EXTRAN and the decision finding model INTL for real time performance, their implementation on a network of UNIX stations and the experiences from running them within an urban drainage real time control project. The main focus is not on what the models do but how they are put into action and made to run smoothly embedded in all the processes necessary in operational real time control.

Fuzzy control of coagulation reaction through streaming current monitoring

1997 ◽  
Vol 36 (4) ◽  
pp. 127-134 ◽  
Author(s):  
J. C. Liu ◽  
M. D. Wu
Keyword(s):  
Fuzzy Logic Controller ◽  
Treatment Plant ◽  
Control Process ◽  
Water Treatment Plant ◽  
Critical Parameters ◽  
Flow Mode ◽  
Raw Water ◽  
Streaming Current ◽  
On Line ◽  
Current Monitoring

A fuzzy logic controller (FLC) incorporating the streaming current detector (SDC) was utilized in the automatic control of the coagulation reaction. Kaolinite was used to prepare synthetic raw water, and ferric chloride was used as the coagulant. The control set point was decided at a streaming current (SC) of −0.05 and pH of 8.0 from jar tests, zeta potential and streaming current measurements. A bench-scale water treatment plant with rapid mix, flocculation, and sedimentation units, operated in a continuous-flow mode, was utilized to simulate the reaction. Two critical parameters affecting the coagulation reaction, i.e., pH and streaming current, were chosen as process outputs; while coagulant dose and base dose were chosen as control process inputs. They were on-line monitored and transduced through a FLC. With raw water of initial turbidity of 110 NTU, residual turbidity of lower than 10 NTU before filtration was obtained. Results show that this combination functions satisfactorily for coagulation control.

Optimisation and control of the inflow to a wastewater treatment plant using integrated modelling tools

1998 ◽  
Vol 37 (1) ◽  
pp. 347-354 ◽  
Author(s):  
Ole Mark ◽  
Claes Hernebring ◽  
Peter Magnusson
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pilot Project ◽  
Integrated Modelling ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
The Impact

The present paper describes the Helsingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Helsingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant. As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.

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