MARITIME TRANSPORT - AN ENVIRONMENTAL PROBLEM WITH BALLAST WATER: TECHNICAL PREVENTIVE MEASURES

Abstract

The fast development of marine transport causes a lot of environmental concerns connected with possible accidents of ships transporting hazardous cargoes as well as oil pollution coming from an exploitation of engine rooms. Moreover, a significant problem is connected with a ballast water handling. The use of ballast water is necessary for the safe movement of large ships. Namely, in maritime transport a ship unloading causes a reduction in its draft – it is a cause of lower steering or even completely prevents the safe movement of the ship. Therefore, in place of the discharged freight the ballast water is collected (often just during the unloading). This water is pumped out from a ship at the site of re-loading. However, this implies the risk of transportation of living organisms over large distances, which (if at the point of discharge of ballast water will find suitable conditions) can become invasive species. Because of the risks involved in carriage of these organisms, the International Maritime Organization (IMO) has developed rigorous standards for permissible amounts of organisms in the discharged ballast water. A number of methods of biological neutralization of ballast water, that meet the requirements of the IMO, have been developed. The topic of this paper is to review currently used methods of neutralization of ballast water. We consider clearing of ballast water from point of view of physics, especially by using electromagnetic radiation and ultrasonic waves.