MELQUISEDEC CORTÉS ZAMBRANO Docente Investigador Universidad Santo Tomas
• SEWER SYSTEM • WWTPs • RIVER
• Separated sewer. • Combined sewer. • CSO .
• Pollutants transported during dry weather. • Contaminants deposited on the basin surface. • Sedimented contaminants in the drainage system.
1. Water flow in the sewer system (river hydraulics): Modelo Type of hyfraulic modelization MOUSE Complete equations of Saint Venant KOSIM Linear reservoirs method SMUSI Kalinin-Miljukov method 2. Accumulation of pollutants :Pollutants on the basin surface 3. Pollutant transport in the sewer system • Contaminants deposited on basin surface. • Fine particles • Conceptual models (Linear reservoirs in series) • Modelos mecanísticos (advection-dispersion equation) • Coarse particles (suspended solids, solids bed, solids washed) • Solid-hydraulic interaction sewer. 4. Chemical and biological transformation. • Changes in water quality.
• Wastewater treatment plant (WWTPs) • Wastewater pretreatment. • Screening, grit removal, flotation. • Primary treatment of wastewater. • Sieving and sedimentation • Secondary treatment. • Activated sludge systems, fixed bed reactors, pond systems, etc. • Control and elimination of nutrients.. • Advanced treatment. • Chemical coagulation, flocculation, activated carbon filters, etc. Treatment technologies: (TPS), (UASB), (WSP), (TF), (AS). Used models: ASM ( Activated Sludge Model) • Simulation of different types of processes (degradation of organic matter, nitrogen, ammonium nitrification, sludge generation, among others). CITY DRAIN (Simplifications based on the estimation of removal percentages.)
• River • Impacts: • Hydraulic. • hydrological • Chemicals. • Biochemicals. • Physical. • Hygienic. • Aesthetic. Modeling becomes more complex.
DESIGN. OPERATION MODELATION. • Sewerage. • Treatment Plant Wastewater WWTP. • River. WHAT IS THE PROBLEM?
• Preservation of public health. • Flood prevention. • This traditional way of thinking about urban drainage, is reflected in the existence of multiple models that only simulate the operation of the system. SUSTAINABLE VISIONS (environmental and economic) • Minimum amount of combined water. • Maximum storage capacity of the system.
• SEWER SYSTEM. The rains and sewage from the city drains into watersheds: Torca River. Salitre River. Fucha River. Tunjuelo River. The Bogotá River is the main receiving waterbody of the drainage system of the city.
1. Torca wetlands – Guaymaral: (73ha; 24 hay 49ha). 2. La Conejera wetlands: (59ha). 3. Córdoba wetlands: (40ha). 4. Juan Amarillo wetlands: (225ha). 5. Santa María del Lago wetlands: (11ha). 6. Jaboque wetlands: (148ha). 7. Capellanía wetlands: (21ha). 8. Techo wetlands: (12ha). 9. El Burro wetlands: (16ha). 10. La Vaca wetlands: (8ha). 11. Tibanica wetlands: (29ha). 12. Meandro del Say wetlands: (26ha).
Significance: Energy disipation structures Impacts: • Fragmentation by the construction of motorways, desiccation and filling, and the destruction of the cover vegetation. • Decrease its hydraulic perimeter. • Water quality. • The wetlands are receiving wastewater discharges from hospitals, agricultural sectors and neighborhoods of the city. • Wrong connections.
PROBLEMS: • High percentage of wrong connections. • Capacity problems. • Inadequate treatment of wastewater. The salitre wastewater treatment plant, has a capacity of 4 m3/s, while the city produces approximately 16 m3/s.
Planning. Management of stormwater systems. Metodology: • Delimitation of the study area. • Diagnostics. • Hydrologic-hydraulic modeling. • Rainfall data and flow. • Hydro-physical characteristics of the watershed. • Selection of return periods. • Model implementation. • Calibration y validation. • Evaluation of the drainage system. • Proposal to improve the hydraulic performance of the system.
• Figure. Bogotá river sanitation plan (source : EAAB, 2010).
• Figure. Traditional vision of urban drainage system (Adapted of Woods-Ballard et al ., 2007).
The current management of drainage systems has proven to be: • Inefficient. • Unsustainable. OPERATING COLOMBIA. • Measures "at the end of the pipe". Which brings to ignore the interactions that occur between the different subsystems. IMPLICATION: • Difficulties in prioritizing investments in sanitation. • Implementation of measures that do not generate the positive impact expected. • Deterioration in water quality of the waterbodies.
Simulate different sanitation alternatives. Considering: • City water receptor bodies (Bogotá river). • The watersheds of major tributaries (Salitre, Fucha y Tunjuelo rivers) • Wetlands. • Involving an integrated system operation. (Combined sewer) Understanding the system in a holistic manner. • Relationships and complexities of the processes involved. • Looking ensure that the quality of water bodies is compatible with the uses of water in the basin.
• Figure. Integrated vision of urban drainage system (Adapted of Woods- Ballard et al ., 2007). • SUDS, BMPs, LID, LIUDD, WSUD. • Minimize runoff. • Reduce hydrologic impacts and water quality. • Maximize biodiversity.
Figure. Urban drainage subsystems and their relationships (taken from: www.acueducto.com.co ).
OBJECTIVE : • Optimize system performance. • Increase control exercised over its operation. • Improve the water quality of the receiving body. • Advances in the efficiency and sustainability of urban drainage systems. IMPLICATION: • Better planning and system operation. • More sustainable solutions. • Reduce impacts on the river.
1. Improving the quality of life of the population. 2. Participation of all sectors involved. 3. Holistic management of water in the basin. 4. Drainage of wastewater must be made on smallest areas.
• SYSTEM ANALYSIS. • Current Status and Operation. • Determining the deficiency. • Identify the relevance and need for integrated modeling. • COLLECTION OF INFORMATION. • Dominant processes • INITIAL CONCEPTUALIZATION OF THE MODEL. • IMPLEMENTATION AND MODEL ANALYSIS. • The model should be flexible. • The model must simulate all system components. • SCENARIO APPROACH. • Projected recovery plan for the city. • SCENARIO SIMULATION AND ANALYSIS. • Quantification of the resulting pollutant load in the river
PROCESSES LIKE : • Calibration. • Validation. Requires a lot of information of the drainage system. • Complex process. • Expensive. • Requires time. You can't make a good an integrated model calibration. Scope of the methodology : • Implementation of the model. • Utilidad del modelo. Using calibrated parameters in different studies for each of the subsystems.
• Reduction of runoff flows, and the consequent reduction in the risk of floodings. • Reduction of the additional runoff volumes which are generated from unpervious urban areas • Minimizing the impact on groundwater (and on basis flow), as a result of increased rainwater infiltration. • Reduction in the peak concentration of pollutants as a result of precipitation events from temporary storage of rain water. • Reduced risk of accidental discharges of pollutants to the water receptor bodies. • Reducing pollution from discharges into combined sewer overflow structures. CSOs. • Contribution to the aesthetics and improve the appearance of urban areas. • Contribution to biodiversity and creating suitable habitats for different species of animals in urban areas.
• Rodríguez, J. P., M. Díaz-Granados, P. Montes and J. Saavedra (2008a). Modelación Integrada de Sistemas de Drenaje Urbano – Caso Bogotá D.C. (Colombia). XXIII Latinamerican Congress on Hydraulic (IARH), Cartagena, Colombia. • Rodríguez, J. P., M. A. Díaz-Granados, L. A. Camacho, I. C. Raciny, Č . Maksimović and N. McIntyre (2008b). Bogotá's urban drainage system: context, research activities and perspectives. BHS 10th National Hydrology Symposium, Exeter. • Rodríguez, J. P., M. A. Díaz-Granados, L. A. Camacho, M. Rodríguez, I. C. Raciny, C. • Maksimovic, N. McIntyre, S. Achleitner, M. Moderl and W. Rauch (In preparation). Case Study III: The case of Bogotá city, Colombia. Integrated Urban Water System Interactions, UNESCO. • Schuetze, M. and J. Alex (2004). Suitable integrated modelling - based on simplified models. 6th International Conference on Urban Drainage Modelling, Dresden.
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