Fuzzy Control of a Dynamic Activated Sludge Process for the Forecast and Control of Effluent Suspended Solid Concentration

The effluent total BOD (or COD) concentration of the activated sludge process (A.S.P.) usually increases with suspended solid concentration. How to reduce effluent S.S. concentration, therefore, is the key issue of treatment efficiency for A.S.P. The varied return sludge and influent flow rate are two major operational factors of those affecting effluent S.S. concentration. However, the wastewater flow rate and substrate concentration in municipal wastewater treatment plant, due to the differences of city scale and life style, are significantly time-varied every day. Based on the above, the purpose of this study is to control in timely fashion return sludge flow rate with the variation of influent flow rate to minimize effluent S.S. concentration and meanwhile decrease the effluent total BOD (or COD) concentration. The fuzzy control theory is utilized in this study to forecast and control effluent S.S. concentration and further predict the MLSS concentration in aeration tank. It reveals that the inferred control strategies not only enable one to decrease effluent S.S.

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Sensitivity of Effluent Variables in Activated Sludge Process

Chemical Product and Process Modeling ◽

10.1515/cppm-2017-0028 ◽

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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Modelling Simulation and Control of an Existing Activated Sludge Wastewater Treatment Process

Water Quality Research Journal ◽

10.2166/wqrj.1976.012 ◽

1976 ◽

Vol 11 (1) ◽

pp. 108-121

Author(s):

N. Thérien ◽

P. Harrington

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Flow Rate ◽

Treatment Plant ◽

Organic Substrate ◽

Activated Sludge Process ◽

Two Phase ◽

Wastewater Treatment Process ◽

Wastewater Stream ◽

And Control

Abstract The dynamic response of the activated sludge process in the wastewater treatment plant of the Centre Hospitalier Universitaire de Sherbrooke was analysed with respect to large disturbances in both the flow rate and the quality of wastewater entering the plant. A mass balance conducted for the organic substrate and biomass entering and leaving the process led to a model consisting of two separate differential equations in terms of BOD and VSS with a two-phase bio-kinetic relationship for the reaction term. Predictions of the model for BOD and VSS variations in time were compared to experimental observations at the plant. A model using mean daily values for VSS and expressed in terms of BOD for the stream flowing out the clarifier unit in response to flow rate and BOD cyclic fluctuations of the entering wastewater stream to the process was found apt at describing the time at which BOD peaks in the process effluent occurred as well as predicting the magnitude of these peaks. The dynamic behaviour of the activated sludge process has been simulated for periods of one to several days using this model. Its use in predicting appropriate control action in time in order to improve the treatment efficiency is also indicated.

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Effluent suspended solid control of activated sludge process by fuzzy control approach

Water Environment Research ◽

10.2175/106143096x128045 ◽

1996 ◽

Vol 68 (6) ◽

pp. 1045-1053 ◽

Cited By ~ 11

Author(s):

Yung-Pin Tsai ◽

Chaio-Fuei Ouyang ◽

Ming-Yang Wu ◽

Wei-Ling Chiang

Keyword(s):

Fuzzy Control ◽

Activated Sludge ◽

Suspended Solid ◽

Activated Sludge Process ◽

Control Approach

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System Identification and Control of the Activated Sludge Process by Use of a Statistical Model

Water Science & Technology ◽

10.2166/wst.1989.0316 ◽

1989 ◽

Vol 21 (10-11) ◽

pp. 1161-1172 ◽

Cited By ~ 8

Author(s):

M. Hiraoka ◽

K. Tsumura

Keyword(s):

Control System ◽

System Identification ◽

Statistical Model ◽

Activated Sludge ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Ar Model ◽

Diurnal Changes ◽

Activated Sludge Process ◽

And Control

The authors have been developing a hierarchical control system for the activated sludge process which consists of an upper level system controlling long-term seasonal variations, a control system of intermediate level aiming at optimization of the process and a control system of lower level controlling diurnal changes or hourly fluctuations. The control system using the multi-variable statistical model is one of the most appropriate control systems based on the modern control theory, for applying the lower level control of the activated sludge process. This paper introduces our efforts for developing the reliable data acquisition system, the control experiments applying the AR-model, one of the statistical models which were conducted at a pilot plant and present studies on the system identification and control at a field sewage treatment plant.

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Multivariable modeling and control of an activated sludge process

Water Science & Technology ◽

10.2166/wst.1998.0527 ◽

1998 ◽

Vol 37 (12) ◽

pp. 149-156 ◽

Cited By ~ 4

Author(s):

Carl-Fredrik Lindberg

Keyword(s):

Activated Sludge ◽

Nitrate Concentration ◽

State Space Model ◽

Activated Sludge Process ◽

Invariant State ◽

Linear Quadratic ◽

Modeling And Control ◽

Space Model ◽

And Control ◽

Time Invariant

This paper contains two contributions. First it is shown, in a simulation study using the IAWQ model, that a linear multivariable time-invariant state-space model can be used to predict the ammonium and nitrate concentration in the last aerated zone in a pre-denitrifying activated sludge process. Secondly, using the estimated linear model, a multivariable linear quadratic (LQ) controller is designed and used to control the ammonium and nitrate concentration.

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Effect of Pressure, Water Depth and Water Flow Rate on Oxygen Saturation Level in Activated Sludge Process

American Journal of Engineering and Applied Sciences ◽

10.3844/ajeassp.2011.435.439 ◽

2011 ◽

Vol 4 (4) ◽

pp. 435-439

Author(s):

Keyword(s):

Activated Sludge ◽

Oxygen Saturation ◽

Water Flow ◽

Flow Rate ◽

Water Depth ◽

Water Flow Rate ◽

Activated Sludge Process ◽

Oxygen Saturation Level ◽

Effect Of Pressure ◽

Pressure Water

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Effect of important operational parameters on performance of coarse pore filtration activated sludge process

Water Science & Technology ◽

10.2166/wst.2002.0246 ◽

2002 ◽

Vol 46 (9) ◽

pp. 229-236 ◽

Cited By ~ 19

Author(s):

M.R. Alavi Moghaddam ◽

H. Satoh ◽

T. Mino

Keyword(s):

Activated Sludge ◽

Aeration Tank ◽

Activated Sludge Process ◽

Operational Parameters ◽

Solid Retention Time ◽

Effluent Quality ◽

Membrane Pores ◽

Filtration Membrane ◽

Operation Pressure ◽

Filter Clogging

A coarse pore filter can be applied inside the aeration tank instead of sedimentation tank for liquid separation from the sludge. It has pores, which are irregular in shape, and much bigger than micro-filtration membrane pores in size. The objective of the study was to investigate the effect of important operational parameters such as flux, aeration intensity, and solid retention time (SRT) on the performance of the coarse pore filtration activated sludge process. The effect of these parameters was studied in laboratory scale experiments. It was found that the flux had a significant role in the effluent quality of this system. The effluent SS and turbidity were not changed significantly at different aeration intensities. Three SRTs, 10, 30 and longer days (without excess sludge) were used for three reactors to check the effect of this parameter on the system performance. The results of the reactors with SRTs about 10 and 30 days have shown very good effluent quality without any filter clogging for more than 4 months operation. For the reactor with long SRT, the filter clogging was observed after about 80 days of operation, which caused the increase of the operation pressure and deterioration in the effluent quality for a few days.

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EFICIÊNCIA DE DIFERENTES ELEMENTOS FILTRANTES NA PREVENÇÃO DE OBSTRUÇÃO DE GOTEJADORES

Irriga ◽

10.15809/irriga.2003v8n1p78-87 ◽

2003 ◽

Vol 8 (1) ◽

pp. 78-87 ◽

Cited By ~ 1

Author(s):

José Euclides Stipp Paterniani ◽

Marcos Eduardo Scatolini

Keyword(s):

Irrigation Water ◽

Suspended Solid ◽

Filter Element ◽

Solid Concentration ◽

Algae Removal ◽

Mesh Screen ◽

Suspended Solid Concentration ◽

E Mail ◽

Synthetic Fabric ◽

Continuous Average

EFICIÊNCIA DE DIFERENTES ELEMENTOS FILTRANTES NA PREVENÇÃO DE OBSTRUÇÃO DE GOTEJADORES José Euclides Stipp Paterniani Marcos Eduardo ScatoliniFaculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas, SP. CP 6011, CEP 13083-970, E-mail: [email protected] 1 RESUMO Durante ensaios para verificação de eficiência de retenção de algas em filtros de discos 120 MESH, tela 120 MESH e manta sintética não tecida, foram avaliados o grau de obstrução de gotejadores de labirinto com fluxo turbulento e vazão nominal de 4 L.h-1 e 8 L.h-1. Para determinação da obstrução causada por impurezas não retidas no meio filtrante foram avaliadas a evolução da vazão e da uniformidade estatística dos gotejadores submetidos aos diferentes meios filtrantes durante um período de 22 semanas durante 4 horas diárias e comparadas com uma parcela testemunha sem elemento filtrante. Os resultados mostraram que houve diferença significativa entre o elemento de discos, que apresentou maior uniformidade estatística, os filtros de manta e tela com valores intermediários e a testemunha que apresentou menor uniformidade estatística. No entanto, para caracterizar de maneira definida a diferença no desempenho dos elementos filtrantes, estes valores deveriam vir acompanhados de uma redução contínua na vazão média dos tratamentos, o que foi observado apenas para o elemento de tela com o gotejador de 4 L.h-1. As demais variações da uniformidade estatística foram temporais, provavelmente devido a obstruções temporárias ocasionadas por variações da concentração de sólidos suspensos na água de irrigação. UNITERMOS: Filtragem, Gotejamento, Qualidade da água. PATERNIANI, J.E.S.; SCATOLINI, M.E. EFFICIENCY OF DIFFERENT FILTER ELEMENTS TO PREVENT TRICKLE CLOGGING 2 ABSTRACT This work aimed to verify the efficiency of algae removal in disks 120 mesh, screen 120 mesh, and non woven synthetic fabric filters. It was evaluated the degree of clogging of turbulent flow drippers on 4 L.h-1 and 8 L.h-1 outflow. For blockage determination the outflow evolution and statistics uniformity (Us) of the dripper have been evaluated when submitted to different filter media over 22 weeks, 4 daily hours compared to a control without the filter element. The results indicated significant differences among the elements. The disk element presented greater statistic uniformity. The screen filter and the non woven synthetic fabric element presented intermediate values whereas the parcel with no filter element (control) presented minor statistic uniformity. However, in order to characterize performance differences among them, values should be presented along with a continuous average outflow reduction in all treatments. This pattern was observed only for the screen filter and 4 L.h-1 drippers. The statistics uniformity variation has been probably caused by temporary blockages due to variation in suspended solid concentration in irrigation water. KEYWORDS: filtration, drip irrigation, water quality.

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Application of synthetic and grafted polymeric flocculants in agricultural wastewater treatment

Journal of Degraded and Mining Lands Management ◽

10.15243/jdmlm.2021.083.2829 ◽

2021 ◽

Vol 8 (3) ◽

pp. 2829-2836

Author(s):

Mohamed N Ali ◽

Mohammed S Fahmy ◽

Rehab M Elhefny

Keyword(s):

Activated Sludge ◽

Agricultural Sector ◽

Aeration Tank ◽

Activated Sludge Process ◽

Sedimentation Stability ◽

Agricultural Wastewater ◽

High Concentrations ◽

Filtration Stage ◽

Organic Particles ◽

Low Dosage

Due to the large amounts of freshwater consumed in Egypt by the agricultural sector that is more than 85% of Egypt share of freshwater in addition to the high concentrations of salts, chemicals and nutrients produced from fertilizers. Reduction of these pollutants concentrations to an acceptable level and breaking the sedimentation stability of colloidal substances and organic particles for reuse for irrigation purposes was associated with the application of biological treatment with coagulants addition. The flocculation process was performed by using polydiallyldimethylammonium chloride (polyDADMAC) and polyacrylamide grafted oatmeal (OAT-g-PAM). The scale-pilot consists of an aeration tank equipped with an air blower, sedimentation tank followed by a filtration stage through 20 cm of pottery scrubs media. To study the performance of synthetic and grafted polymeric flocculants, 3 trials were performed. Activated sludge process without adding any polymeric flocculants was the control trial. In the second trial, polyDADMAC was added with a dose of 5 mg/l. Finally, OAT-g-PAM with a dose of 1.25 mg/l was used in the third trial. The physicochemical properties of agricultural wastewater were measured at the national research center in Cairo. It was found that OAT-g-PAM incorporated with activated sludge process was the most effective in treating agricultural wastewater as it achieved COD, BOD,TKN, TP, and TSS removal efficiency up to 92.29%, 93.13%, 90.64%, 90.46%, and 92.5%, respectively which made it suitable to reuse for agricultural purposes, in addition to its ability to biodegrade, environmentally friendly, and low dosage required compared to polyDADMAC.

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