METHOD AND APPARATUS FOR TREATING BALLAST WATER USING STACK GAS FROM A MARINE ENGINE

摘要

The present invention relates to a method and apparatus for treating the stack gas (CO2) that causes global warming as well as for processing ballast water that threatens marine ecosystems. The present invention is an environmentally-friendly treatment method that can control and avoid marine contamination and air pollution at the same time, using the fact that marine microorganisms in the ballast water are destroyed at a low pH (acidity) and the pH can be lowered by using the stack gas from the ship. The method comprises: (1) filtering ballast water that is subject to microbiological treatment in one step and then storing for use in a ballast water tank; (2) transferring the ballast water from the ballast water tank to a ballast water treatment tank, lowering the temperature of PM(particulate material)-free stack gas from a marine engine through heat exchange and then bringing the stack gas into contact with the ballast water to change the concentration of hydrogen ions (i.e. adjusting the pH of the ballast water with acid), thereby primarily destroying and removing marine microorganisms in the ballast water; and (3) transferring the ballast water that has undergone the pH adjustment to destroy and treat the marine microorganisms to a discharge tank, and then increasing the temperature of the ballast water that is being discharged through heat exchange with the stack gas, to induce secondary destruction of any remaining marine microorganisms as well as to get rid of gases including carbon dioxide and nitrogen oxide remaining in the ballast water, such that the concentration of hydrogen ions in the ballast water is made equal to the concentration of hydrogen ions in sea water, achieving a proper concentration level for hydrogen ions to be discharged. Therefore, the present invention provides a more environmentally-friendly and effective apparatus in treatment of ballast water for removing marine microorganisms in ballast water.