In this module the detailed design of a municipal wastewater treatment plant is realized. This includes the sanitary engineering calculations, the hydraulic study, the technical choices that should be made and the overall plant layout. The design includes the dimensioning of the pre-treatment works, the primary sedimentation, the biological treatment, the tertiary treatment works and the management and treatment of sludge through thickening, anaerobic digestion and dewatering. Furthermore, some special topics are covered such as the design of the aeration system, the management and valorisation of biogas and automation works. Finally, this module covers membrane bioreactors and attached growth processes applied for municipal wastewater treatment and how operating problems are confronted.
# | Title | Description | Hours |
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1 | Introduction to water treatment | Brief revision of the basic processes involved in the treatment, disposal and reuse of wastewater and sludge with reference to the relevant legislation. Quantitative and qualitative characterization of sewage, description of the stages involved in the works concerning the construction and disposal of municipal wastewater. | 1Χ4=4 |
2 | Activated sludge process with nutrient removal | Activated sludge process with nutrient removal, nitrification/denitrification, biological and chemical phosphorus removal, kinetics, stoichiometry, design principles. | 2Χ4=8 |
3 | Design of wastewater pre-treatment and primary treatment works | Design of pre-treatment works (initial pumping, inlet works, mechanical screening, aerated sand removal, oil and grease removal and flow measurement) and of primary treatment (circular and rectangular sedimentation tanks), management of the by-products of the pre-treatment works (screenings, sand, oil and grease). Mass balances, equipment automation, examples solved in class | 1,5Χ4=6 |
4 | Design of biological treatment works | Design of the activated sludge process for the removal of organic carbon, nitrogen and phosphorus. Determination of kinetics and solids retention time, excess sludge and sludge recycle as well as of the mixed liquor suspended solids. Mass balance of nitrogen and phosphorus. Design of the unit for chemical phosphorus removal. Design of the final sedimentation tanks and of the pumping station of excel sludge and sludge recycle. Equipment automation, examples solved in class | 2,5Χ4=10 |
5 | Tertiary treatment works – disinfection and disposal works. Reclaimed water reuse and relevant legislation | Tertiary treatment of sewage (sand filters, membranes, advanced processes). Disinfection systems (chlorination, UV irradiation, ozonation). Works for the discharge of the treated effluent (discharge pipe, diffusers). Legislative framework regarding the reclaimed water reuse. | 1Χ4=4 |
6 | Design of sludge treatment and biogas management works; sewage sludge sanitization and potential reuse of sludge | Design of sludge thickening works (mechanical and gravity thickening), anaerobic digestion (mixing and heating of digester, geometric characteristics), dewatering (drying beds, mechanical thickening). Mass balances. Energy – thermal balances for the anaerobic digestion unit. Introduction to the management and valorization of biogas (biogas storage, combined heat and power units, boilers). Sludge sanitization and use. Equipment automation, examples solved in class. | 2Χ4=8 |
7 | Basic principles of hydraulic calculations and layout of the works | Basic principles of the layout of wastewater and sludge treatment units. Auxiliary works (buildings, management of sludge reject water, rainwater, industrial water and drainage), road construction, landscape formulation. Hydraulic design of works. Development of the geometry of tanks and pumping stations. | 1Χ4=4 |
8 | Design of aeration system for the aeration tank | Basic principles of aeration systems design (diffuse aeration, surface aeration). Calculation of blowers and diffusers. Calculation of energy requirements of aeration systems. Basic principles for the reduction of energy consumption. Equipment automation, examples solved in class. | 1Χ4=4 |
9 | Membrane bioreactors and attached growth processes | Basic principles of membrane bioreactors (MBRs); Attached growth processes; Basic design principles | 1Χ4=4 |
After the successful completion of this module students will be able to:
Teaching methods | Class lectures, demonstration of technologies, Solving of examples in class (one for each treatment stage for wastewater and sludge), discussion concerning case studies in class, design solutions |
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Teaching media | Blackboard use, powerpoint presentations, YouTube videos, solving problems in class, solving a real design case, calculations in PC, visit to a wastewater treatment plant, |
Computer and software use | The students implement their design of the wastewater treatment plant using design software and PC |
Assignments (projects, reports) | Each student has to carry out the design of a municipal wastewater treatment plant. The deliverables consist of a technical report consisting of the sanitary calculations, the hydraulic calculations as well as the drawings of the general layout of the plant works |
Student presentations | The students have to present at the final examination their overall design in detail. |
Class notes and power point presentations
A. Andreadakis (2015) Treatment and management of wastewater and sludge, NTUA (in Greek)