On-Line Estimation of the Respiration Rate in an Activated Sludge Process

1993 ◽  
Vol 28 (11-12) ◽  
pp. 427-434 ◽  
Author(s):  
Bengt Carlsson
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Piecewise Linear ◽  
Oxygen Transfer Rate ◽  
Activated Sludge Process ◽  
Data Set ◽  
Loop Control ◽  
Novel Approach ◽  
On Line

In this paper, a novel approach to estimate the respiration rate in an activated sludge process is developed. The proposed estimator for the respiration rate is simple to implement and can be used during normal closed loop control of the dissolved oxygen. The basic idea is to use a two step procedure where in the first step, a model of the oxygen transfer rate KLa is estimated from a data set. The nonlinear KLa function is modelled with a static, constrained, piecewise linear model. In the second step, the respiration rate is estimated from measurements of dissolved oxygen concentration and air flow rate using the KLa model obtained in step 1.

Improving oxygen concentration control in activated sludge process with estimation of respiration and scheduling control

2006 ◽  
Vol 53 (4-5) ◽  
pp. 283-291 ◽  
Author(s):  
S. Gerkšič ◽  
D. Vrečko ◽  
N. Hvala
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Oxygen Concentration ◽  
Pi Controller ◽  
Activated Sludge Process ◽  
Dissolved Oxygen Concentration ◽  
Integral Control ◽  
Process Dynamics ◽  
On Line ◽  
The Cost

The paper presents an efficient and simple model-based method of on-line estimation of respiration from the current values of dissolved oxygen concentration and airflow signals. Fast estimation of respiration is important because respiration appears as the most important disturbance signal in the control of dissolved oxygen concentration, and could therefore be used for improving control efficiency. A parameter scheduling PI (proportional and integral) control scheme is proposed, where the estimated respiration signal is used for scheduling of the PI controller parameters, by using local linearization of the process dynamics. The performance of the scheduling controller is compared to a conventional PI controller in simulation using the COST simulation benchmark, and experimentally on an activated sludge process pilot plant.

ON-LINE ESTIMATION OF THE RESPIRATION RATE AND THE OXYGEN TRANSFER RATE AT KUNGSANGEN W ASTEW ATER TREATMENT PLANT IN UPPSALA

1994 ◽  
Vol 30 (4) ◽  
pp. 255-263 ◽  
Author(s):  
B. Carlsson ◽  
C.-F. Lindberg ◽  
S. Hasselblad ◽  
S. Xu
Keyword(s):  
Respiration Rate ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Piecewise Linear ◽  
Oxygen Transfer Rate ◽  
Treatment Plant ◽  
Real Data ◽  
Municipal Sewage ◽  
Process Diagnosis ◽  
On Line

In this paper, a method for on-line estimation of the oxygen transfer rate (KLa) and the respiration rate is successfully evaluated on real data from the municipal sewage plant Kungsängen in Uppsala, Sweden. Possible applications for the estimator include process diagnosis and model based control. The estimator is based on a Kalman filter approach where the oxygen transfer ra.te is modelled with a static, constrained, piecewise linear model and the respiration rate is modelled as a random walk, The paper also presents experience with using an autotuning controller for the control of the dissolved oxygen concentration.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

Sensitivity of Effluent Variables in Activated Sludge Process

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
B Vivekanandan ◽  
K Jeyannathann ◽  
A. Seshagiri Rao
Keyword(s):  
Activated Sludge ◽  
Flow Rate ◽  
Oxygen Transfer Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Maximum Flow ◽  
Activated Sludge Process ◽  
Flow Conditions ◽  
Treated Effluent ◽  
Influent Flow

Abstract The quality of a treated effluent changes when there is a sudden variation in the influent flow to the wastewater treatment plant during dry, rain, and storm weather conditions. In this study, various influent flow conditions in an activated sludge process are considered that affect the sensitivity of effluent variables such as chemical oxygen demand (COD), biological oxygen demand (BOD), nitrate nitrogen (SNO), ammonical nitrogen (SNH), and total nitrogen (TN) with respect to varying internal recycle flow rate (Qa), sludge recycle flow rate (Qr), sludge wastage flow rate (Qw) and oxygen transfer rate co-efficient of aerobic tanks (KLa(3,4,5)). The analysis has been carried out based on benchmark simulation model no.1 (BSM 1) plant layout which comprises of two models namely activated sludge model no.1 (ASM 1) and simple one dimensional (Simple 1-D) Takacs model. Based on the present analysis, it is observed that the changes in influent flow rate have larger impact on the effluent variables. This variation can be subdued by introducing additional tanks to smoothen the perturbations or using internal recycle rate from the fifth tank in order to maintain the flow around the optimal influent flow rate. The sludge wastage rate has a greater impact on all effluent variables except nitrogenous variables during maximum flow conditions.

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