Designing Low Impact Wastewater Discharge from Solar Distillation Site to Sea

Document Type: Research Paper

Authors

1 Department of Civil Engineering, Tonekabon Branch, Islamic Azad University

2 Department of Civil Engineering, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran.

Abstract

Dry areas near the sea can obtain fresh water through solar distillation of saline sea water resources. However, these solar distillation sites produce wastewater as a result of desalination of sea water with high salt concentration. Waste must be disposed of with the least effect on the receiving environment (sea, in most cases). Initial dilution and its characteristics play important roles in designing effluent disposal into the sea. Application of a mixing model is a common approach for estimating the initial dilution. The present study, using empirical equations, has applied jet system for waste disposal of Kish Port solar desalination site. Initial dilution is related to water depth, diameter, flow rate, the distance between the opening outlets and velocity of water. The results showed the critical and the best initial dilution with regard to different environmental conditions. Effluent disposal systems were compared including jet system of solar distillation in Kish Port and the disposal system of Khamir Port. The minimum velocity and density occurred in the vertical channels zone which shows a well-dilution system that prevents deposition of wastewater into the sea floor. The performance of the T-shaped diffuser for waste disposal is cheaper than the jet system, and it occupies the length of duct from beach to sea.