Coiling attached with UV source and gas inlet for ballast water treatment: An effective physical method for ballast water treatment
Ships carry giant volume of ballast water required to sink in Sea. The loading and unloading of ballast water causes negative impact on marine environment. The discharged ballast water typically contains both macroscopic and microscopic plants, animals, bacteria, fungi and viruses. It is mandatory to treat ballast water by eco-friendly means. Biofouling of large macroscopic animals and their invasion is difficult to control. Microbial biofouling can be effectively controlled using physicochemical, physical enhancement and residual control method. Physical measures include UV irradiation, UV + TiO2, deoxygenation, gas injection, ultrasonic treatment, and cavitation. These methods are carried out by using pipes having UV tubes and gas inlet. Because of high speed of pumping water in and out, pathogenic microorganisms either exposed for less time to UV light or the dissolution rate of gas is very less. This problem can be overcome by the use of coiling with UV tubes and gas inlet system and borosilicate UV tubes submerged in the ballast tanks. It increases the exposure of pathogenic microorganisms to UV light and gas for longer period of time. This method is effective in reduction of pathogenic province and may be used as alternative method for the ballast water treatment.