Improvement of Activated Sludge Process Using Enhanced Nonlinear PI Controller

2014 ◽  
Vol 39 (8) ◽  
pp. 6575-6586 ◽  
Author(s):  
S. I. Samsudin ◽  
M. F. Rahmat ◽  
N. A. Wahab ◽  
M. C. Razali ◽  
M. S. Gaya ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Pi Controller ◽  
Activated Sludge Process

Automatic control for DO and pH in the activated sludge process in a coke wastewater treatment plant

1998 ◽  
Vol 37 (12) ◽  
pp. 141-148 ◽  
Author(s):  
B. K. Lee ◽  
S. W. Sung ◽  
H. D. Chun ◽  
J. K. Koo
Keyword(s):  
Wastewater Treatment ◽  
Control System ◽  
Activated Sludge ◽  
Automatic Control ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pi Controller ◽  
Activated Sludge Process ◽  
Set Point ◽  
Coke Wastewater

The objective of this study is to develop an automatic control system for dissolved oxygen (DO) and pH of the activated sludge process in a coke wastewater treatment plant. A discrete type autotuned proportional-integral (PI) controller using an auto-regressive exogenous (ARX) model as a process model was developed to maintain the DO concentration in aerators by controlling the speed of surface aerators. Also a nonlinear pH controller using the titration curve was used to control the pH of influent wastewater. This control system was tested in a pilot scale plant. During this pilot plant experiment, there was small deviation of pH and the electric power consumption of surface aerators was reduced up to 70% with respect to the full operation when the DO set point was 2 mg/l. For real plant operation with this system, the discrete PI controller showed good tracking for set point change. The electricity saving was more than 40% of the electricity consumption when considering surface aerators. As a result of maintaining the DO constantly at the set point by the automatic control system, the fluctuation of effluent quality was decreased and overall improvement of the effluent water quality was achieved.

Improvement of ammonia removal in activated sludge process with feedforward-feedback aeration controllers

2006 ◽  
Vol 53 (4-5) ◽  
pp. 125-132 ◽  
Author(s):  
Darko Vrečko ◽  
Nadja Hvala ◽  
Aljaž Stare ◽  
Olga Burica ◽  
Marjeta Stražar ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Pi Controller ◽  
Ammonia Removal ◽  
Activated Sludge Process ◽  
Aerobic Reactor

In the paper three linear aeration controllers that can be easily implemented are presented and evaluated on the activated sludge process pilot plant. Controllers differ according to the information that is used about the process, which can be oxygen in the last aerobic reactor, ammonia in the last aerobic reactor and ammonia in the influent. The aeration controllers that are addressed are: oxygen cascade PI controller, ammonia cascade PI controller and ammonia feedforward-cascade PI controller. Experiments show that, in comparison with the oxygen cascade PI controller, the ammonia cascade PI controller allows better control of effluent ammonia and airflow savings of around 23%, while the ammonia feedforward-cascade PI controller gives the best reduction of ammonia peaks and can save up to 45% of the airflow.

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.

The application of model predictive control of ammonia nitrogen in an activated sludge process

2011 ◽  
Vol 64 (5) ◽  
pp. 1115-1121 ◽  
Author(s):  
D. Vrečko ◽  
N. Hvala ◽  
M. Stražar
Keyword(s):  
Activated Sludge ◽  
Prediction Interval ◽  
Ammonia Nitrogen ◽  
Pi Controller ◽  
Ammonia Removal ◽  
Activated Sludge Process ◽  
Pi Controllers ◽  
Predictive Controller ◽  
Control Criteria ◽  
Improved Accuracy

In this paper a model predictive controller (MPC) for ammonia nitrogen is presented and evaluated in a real activated sludge process. A reduced nonlinear mathematical model based on mass balances is used to model the ammonia nitrogen in the activated sludge plant. An MPC algorithm that minimises only the control error at the end of the prediction interval is applied. The results of the ammonia MPC were compared with the results of the ammonia feedforward-PI and ammonia PI controllers from our previous study. The ammonia MPC and ammonia feedforward-PI controller give better results in terms of ammonia removal and aeration energy consumption than the ammonia PI controller because of the measurable disturbances used. On the other hand, with the ammonia MPC, comparable or even slightly poorer results than with the ammonia feedforward-PI controller are obtained. Further improvements to the MPC could be possible with an improved accuracy of the nonlinear reduced model of the ammonia nitrogen, more sophisticated control criteria used inside the controller and the extension of the problem from univariable ammonia to multivariable total nitrogen control.

DESIGN PLANNING WASTEWATER TREATMENT PLANT OF NATA DE COCO INDUSTRY WITH THE ACTIVATED SLUDGE PROCESS

2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Dinda Rita K. Hartaja ◽  
Imam Setiadi
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Appropriate Technology ◽  
Waste Water Treatment Plant ◽  
Activated Sludge Process ◽  
High Level

Generally, wastewater of nata de coco industry contains suspended solids and COD were high, ranging from 90,000 mg / l. The high level of of the wastewater pollutants, resulting in nata de coco industry can not be directly disposed of its wastewater into the environment agency. Appropriate technology required in order to process the waste water so that the treated water can meet the environmental quality standards that are allowed. Designing the waste water treatment plant that is suitable and efficient for treating industrial wastewater nata de coco is the activated sludge process. Wastewater treatment using activated sludge process of conventional (standard) generally consists of initial sedimentation, aeration and final sedimentation.Keywords : Activated Sludge, Design, IPAL

Process evaluation of HASP with IMET system through SNR and SDNR for the efficient management of Sewage Treatment Plant

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Young H. Yoon ◽  
Jae R. Park ◽  
Sang W. Ahn ◽  
Kwang B. Ko ◽  
Kyung J. Min ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Linear Regression Analysis ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Reaction Rates ◽  
Nitrification Rate ◽  
Activated Sludge Process ◽  
Type Experiment ◽  
Batch Type ◽  
Nitrification And Denitrification

Hybrid Activated Sludge Process (HASP) with IMET was developed and applied to an activated sludge process for the advanced nutrient treatment in Korea. The characteristics of nitrogen removal from the HASP were investigated through a kinetic study by batch-type experiment. Online DB analysis produced from the IMET was conducted for the nutrient removal performance in the field demonstration plant treating 10,000 m3/day in G city of Korea. In this paper, we aimed to determine the effect of increasing NHM4+-N load on the specific nitrification rate (SNR) and the specific denitrification rate (SDNR) through a batch-type experiment, and to estimate the net reaction time for the phase-transfer rate using online DB analysis in the HASP operation. Experimental results include: (1) both the nitrification and denitrification followed first-order kinetics; (2) the maximum SNR and SDNR were 4.0301 mgN/gVSS·hr and 2.785 mgN/gVSS·hr, respectively; (3) comparison of reaction rates between nitrification and denitrification from the non-linear regression analysis found that nitrification rate was higher than denitrification.

Deemulsification of Water-in-Oil Emulsion with Sludges

1987 ◽  
Vol 22 (3) ◽  
pp. 437-443 ◽  
Author(s):  
N. Kosaric ◽  
Z. Duvnjak
Keyword(s):  
Activated Sludge ◽  
Room Temperature ◽  
Petroleum Refinery ◽  
Treatment Plant ◽  
Granular Sludge ◽  
Activated Sludge Process ◽  
Sludge Treatment ◽  
Oil Emulsion ◽  
Water In Oil Emulsion ◽  
Aerobic Sludge

Abstract Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature. An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect. The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.

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