Determination of Thermal Pollution Effect on End Part of Stream

Abstract

The present study was conducted to evaluate the environmental impact of thermal effluent sources on the main water quality parameters at the low flow conditions. The low flow causes the flow velocity to be low which causes accumulation of any pollutant source. The study was performed by creating a 2-d model of the last reach of Rosetta branch at winter closure. Delft 3d software is used to create a hydro-dynamic model to simulate the flow pattern within a 5 km of the branch upstream Edfina regulator. Water quality model is coupled afterwards to simulate the water quality parameters. A base case scenario of the current state at the low flow condition is set up and calibrated. Another scenario is performed after adding a thermal pollutant source. Thermal power plant is used as an application of thermal pollutant source. Cooling water is with drawled from an intake and discharged back to the water source with a relatively higher temperature downstream the intake. A case study of Dairut thermal power plant which is planned to be constructed at this area is used. Hydrographic survey is performed to collect essential hydraulic data for the model. Field measurements are performed to collect water quality along the area. A numerical model was set up and the area was simulated. Results showed accumulation of thermal plume. The higher temperatures lowered the dissolved oxygen in the thermal plume area. On the other hand, BOD and NO3 values increased with different rates. Ammonium was positively affected and was lowered.