Fundamental nonlinearities of the reactor-settler interaction in the activated sludge process

2012 ◽  
Vol 66 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Stefan Diehl ◽  
Sebastian Farås
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Practical Importance ◽  
Simulation Models ◽  
Nonlinear Process ◽  
Normal Operation ◽  
Activated Sludge Process ◽  
General Rules ◽  
Input Variables ◽  
Soluble Substrate

The activated sludge process can be modelled by ordinary and partial differential equations for the biological reactors and secondary settlers, respectively. Because of the complexity of such a system, simulation models are most often used to investigate them. However, simulation models cannot give general rules on how to control a complex nonlinear process. For a reduced-order model with only two components, soluble substrate and particulate biomass, general results on steady-state solutions have recently been obtained, such as existence, uniqueness and stability of solutions. The aim of the present paper is to utilize those results to formulate some implications of practical importance. In particular, strategies are described for the manual control of the effluent substrate concentration subject to the constraint that the settler is maintained in normal operation (with a sludge blanket in the thickening zone) in steady state. Such strategies contain how the two control parameters, the recycle and waste volumetric flow ratios, should be chosen for any (steady-state) values of the input variables.

Operational Determination of the Activated Sludge Process Using Neural Networks

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2461-2464 ◽  
Author(s):  
R. D. Tyagi ◽  
Y. G. Du
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Steady State ◽  
Activated Sludge ◽  
Feedforward Neural Network ◽  
Training Data ◽  
Activated Sludge Process

A steady-statemathematical model of an activated sludgeprocess with a secondary settler was developed. With a limited number of training data samples obtained from the simulation at steady state, a feedforward neural network was established which exhibits an excellent capability for the operational prediction and determination.

The effect of chemical settling on the kinetics and design of activated sludge for tannery wastewaters

1998 ◽  
Vol 38 (4-5) ◽  
pp. 355-362 ◽  
Author(s):  
D. Orhon ◽  
S. Sözen ◽  
E. Ubay Çokgör ◽  
E. Ates Genceli
Keyword(s):  
Activated Sludge ◽  
Practical Importance ◽  
Oxygen Demand ◽  
Component Model ◽  
Activated Sludge Process ◽  
Effluent Quality ◽  
And Performance ◽  
Aeration Volume ◽  
Kinetic Pattern ◽  
Biological Treatability

The effect of chemical settling of tannery wastewaters on the kinetic behaviour and performance of activated sludge process is investigated on the basis of experimentally supported model evaluations. Experiments involved besidese conventional characterization, detailed COD fractionation and assessment of major kinetic and stoichiometric coefficients by means of respirometric measurements. A multi-component model based on the endogenous decay concept was used for the kinetic interpretation and design of activated sludge. Results indicated that chemical settling as a pretreatment step induced a totally different kinetic pattern, significantly improving the biological treatability of tannery wastewaters. Design implications were evaluated in terms of major parameters of practical importance, such as effluent quality, activated sludge composition, aeration volume, oxygen demand and sludge generation.

Experiences in wastewater characterization and model calibration for the activated sludge process

1996 ◽  
Vol 33 (12) ◽  
pp. 89-98 ◽  
Author(s):  
Xu Shulan ◽  
Bengt Hultman
Keyword(s):  
Activated Sludge ◽  
Model Calibration ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Simulation Models ◽  
Activated Sludge Process ◽  
Model Simplification ◽  
Municipal Wastewater Treatment ◽  
Oxygen Utilization ◽  
Parameter Values

Simulation models of the activated sludge process are believed to be a useful tool for process optimization and trouble-shooting at today's treatment plant. However, the application of the models is limited at most treatment plants due to lack of advanced input of parameter values required by the model. Simplification of the procedures of wastewater characterization was investigated. Characterization work was reduced to two oxygen utilization measurements and two COD analyses. Model calibration is demonstrated with experimental data from Kungsängen municipal wastewater treatment plant in Uppsala, Sweden.

scholarly journals New explicit formulations for accurate estimation of aeration-related parameters in steady-state completely mixed activated sludge process

2017 ◽  
Vol 19 (1) ◽  
pp. 140-159 ◽  
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Energy Consumption ◽  
Activated Sludge ◽  
Transfer Coefficient ◽  
Total Mass ◽  
Activated Sludge Process ◽  
Oxygen Requirement ◽  
Design Variables ◽  
Daily Energy

<p>This paper presents new and explicit equations to estimate aeration-related parameters such as standard oxygen requirement, daily energy consumption and total mass transfer coefficient for the diffused aeration. The proposed formulations are derived for the steady-state completely mixed activated sludge process based on the nonlinear regression analysis by using the Richardson’s extrapolation method and the Levenberg–Marquardt algorithm. The applicability of the proposed models has been investigated for a wide range of thirteen inputs consisting of the fundamental biological, hydraulic, and physical design variables, and tested against a total of 1500 additional computational scenarios. All estimations are proven to be satisfactory with very high determination coefficients (<em>R</em><sup>2</sup>) between 0.961–0.965, 0.967–0.972 and 0.980–0.984, respectively, for the prediction of standard oxygen requirement, daily energy consumption and total mass transfer coefficient for diffused aeration. The proposed models offer sufficiently simple and practical mathematical formulations incorporating routinely obtainable parameters, which are readily available for all activated sludge-based treatment plants. Besides eliminating the need for additional time or computational effort typically performed in the theoretical procedure, the developed equations have simple coefficients to be easily used for manual calculations with a hand-held calculator. The statistical results clearly exhibit that the proposed equations are accurate enough to be used in estimation of the studied aeration parameters based on the practical ranges of the corresponding design variables.</p>

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.

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