Nitrogen Removal to Minimize Energy Consumption of the Two WWTPs Choutrana II and Menzel Bourguiba in Tunisia
-
Slim Hajji
,
Hedi Shayeb
Abstract
The control of the aeration time and the dissolved oxygen in a reactor plays an important role in the management of the plant and the reduction of energy consumption. For this, two full-scale municipal wastewater treatment plants were chosen. The first plant (Choutrana II) designed for 600,000 population-equivalents (p.e), consists of a primary treatment step (screening, grit and grease removal), followed by four parallel oxidation ditches with a total volume of 60,000 m3. Aeration is ensured by air diffuser. The second plant (Menzel Bourguiba) designed for 140,000 p.e consists of a primary treatment stage (screening, grit and grease removal), followed by anoxic tanks and two aerobic reactors with a total volume of 14,000 m3. Aeration is ensured by six surface aerators which are operated episodically to create aerobic and anoxic conditions. Currently, the aeration management is controlled by a timer with a maintained oxygen concentration at a given level in the aerobic reactor. The nitrogen removal is done during air-on and air-off periods. The process can be seen as a succession of aeration periods followed by an anoxic period. This category of plant operation is far from the optimal and raises energy consumption and operative costs. The purpose of this study is to implement a new strategy to control aeration taking into account the variation of the daily organic load received by plants (feedforward control) and to create favorable conditions for nitrification and denitrification steps (feedback control). The Activated Sludge Model 1, which is calibrated and validated by respirometry tests, is used. Simulation results show the potentialities of the chosen strategy, which could save 28% of aeration energy and could adjust the aerobic and anoxic times. As first results, daily aeration time could be considered enough to produce treated water conform to standard terms. For Choutrana II plant, the results obtained have allowed to achieve a nitrogen removal rate of 85% and an output concentration between 6 and 12 mg/L. Rates of nitrification and denitrification were estimated at 4 mg NO3-N/L/h and 6 mg NH4-N/L/h, respectively. At the same time, aeration periods (on/off) are connected with daily organic load received by the plant and created favorable conditions for nitrification–denitrification. A good agreement between input biological loads, aeration profile and nitrogen removal is approved.
Acknowledgments
The author thanks the head of GREEN LAB laboratory for his support in sampling and analyzing the results. This work was partially supported by the Tunisian National Agency of Sanitation.
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Artikel in diesem Heft
- Frontmatter
- A Novel Catalyst Preparation Technique to Improve Performance of Ni/γ-Al2O3 Catalysts in Partial Oxidation of Methane
- Characterization and Deactivation Study of Mixed Vanadium and Potassium Oxide Supported on Microemulsion-Mediated Titania Nanoparticles as Catalyst in Oxidative Dehydrogenation of Propane
- Effect of Titania Loading on Properties and Catalytic Activity of Nanostructured Phosphate–Vanadia-Impregnated Silica–Titania Oxidative–Acidic Bifunctional Catalyst
- Effects of Partial Slip on Chemically Reactive Solute Distribution in MHD Boundary Layer Stagnation Point Flow Past a Stretching Permeable Sheet
- Heat and Mass Transfer of Thermophoretic MHD Flow of Powell–Eyring Fluid over a Vertical Stretching Sheet in the Presence of Chemical Reaction and Joule Heating
- Integration of Optimization and Model Predictive Control of an Intensified Continuous Three-Phase Catalytic Reactor
- Kinetics of Reactive Extraction of Pyruvic Acid Using Tributylamine Dissolved in n-Butyl Acetate
- Mathematical Modeling, Verification and Optimization for Catalytic Membrane Esterification Micro-reactor
- Metal-Foam-Supported Pd/Al2O3 Catalysts for Catalytic Combustion of Methane: Effect of Interaction between Support and Catalyst
- Simulation of Soot Size Distribution in a Counterflow Flame
- Study on Effective Radial Thermal Conductivity of Gas Flow through a Methanol Reactor
- Surface Functionalization and Magnetic Motion of Hydrophobic Magnetic Nanoparticles with Different Sizes
- Towards Production of γ-valerolactone via Hydrogenation of Aqueous Levulinic Acid
- Nitrogen Removal to Minimize Energy Consumption of the Two WWTPs Choutrana II and Menzel Bourguiba in Tunisia
Artikel in diesem Heft
- Frontmatter
- A Novel Catalyst Preparation Technique to Improve Performance of Ni/γ-Al2O3 Catalysts in Partial Oxidation of Methane
- Characterization and Deactivation Study of Mixed Vanadium and Potassium Oxide Supported on Microemulsion-Mediated Titania Nanoparticles as Catalyst in Oxidative Dehydrogenation of Propane
- Effect of Titania Loading on Properties and Catalytic Activity of Nanostructured Phosphate–Vanadia-Impregnated Silica–Titania Oxidative–Acidic Bifunctional Catalyst
- Effects of Partial Slip on Chemically Reactive Solute Distribution in MHD Boundary Layer Stagnation Point Flow Past a Stretching Permeable Sheet
- Heat and Mass Transfer of Thermophoretic MHD Flow of Powell–Eyring Fluid over a Vertical Stretching Sheet in the Presence of Chemical Reaction and Joule Heating
- Integration of Optimization and Model Predictive Control of an Intensified Continuous Three-Phase Catalytic Reactor
- Kinetics of Reactive Extraction of Pyruvic Acid Using Tributylamine Dissolved in n-Butyl Acetate
- Mathematical Modeling, Verification and Optimization for Catalytic Membrane Esterification Micro-reactor
- Metal-Foam-Supported Pd/Al2O3 Catalysts for Catalytic Combustion of Methane: Effect of Interaction between Support and Catalyst
- Simulation of Soot Size Distribution in a Counterflow Flame
- Study on Effective Radial Thermal Conductivity of Gas Flow through a Methanol Reactor
- Surface Functionalization and Magnetic Motion of Hydrophobic Magnetic Nanoparticles with Different Sizes
- Towards Production of γ-valerolactone via Hydrogenation of Aqueous Levulinic Acid
- Nitrogen Removal to Minimize Energy Consumption of the Two WWTPs Choutrana II and Menzel Bourguiba in Tunisia
