Assessment of marine disposal system using Cormix model in southern Caspian Sea

The discharge of sewage to the sea and ocean can be an issue of public and scientific concern. Numerical modeling is a prediction tool useful for the design of discharge configurations and for environmental impact assessment. In this paper, CORMIX2 was used to analyze and predict the discharge system design in Babolsar (Iran). Data on wind, current and position in relation to the coast of Babolsar were used in the chosen case to obtain reasonable geometry of outfall. Structure of outfall was simulated by Cormix2 for both stratified and unstratified condition. Sanitary wastewater (dry weather) was discharged through the outfall, extending 6600m offshore in a depth of 34.15m. Maximum flow rate for both dry and wet weather outfall were 0.653 and 1.253 m3s-1, respectively. The wet weather system was located 1200m offshore with the discharged depth of 14.53m. The obtained results indicate maximum amount of dilution was in angle (SIGMA) 45˚, angle (THETA) 20˚ and angle (GAMMA) 90˚. Dilution was obtained in wet weather and in dry weather. Results of modeling indicated the effects of discharge velocity on initial dilution was more than diffuser length in stratified condition (dry weather) whereas the effects of the diffuser length on initial dilution was more than discharge velocity in unstratified condition (wet weather).

Keywords:

Diffuser , Cormix2 , angle , discharge , stratified , unsratified