Experimental Study On The Air Flotation And Hydrocyclonic Separation Of The Algae Removal For Ballast Water

Nowadays, the issue of biological invasion caused by ocean shipping transfer of shipboard ballast has aroused increasing attention from the international community. A large number of marine organisms in ballast water is a global dissemination of damages about the marine biological diversity and ecological balance of coastal area. In order to protect and improve the marine environment, and help China's ocean shipping business adapt to the demand of drafting International Ship Ballast Water and Sediments of the Convention Management and Control by International Maritime Organization (IMO), the project, Ocean Shipping Ballast Water Treatment System of Physical Purification, supported by national scientific and technology plan, was brought up and carried out. Therefore, Algae removal is the most difficult point in the research of removing the suspended algae. This paper describes the theoretical and experimental studies of the combination of the air flotation and drocyclonic separation.Because air flotation process is conventional static, and restricted by the separation time and particle size, it can not be directly used to remove algae. In additional, drocyclonic separation mainly is used for the separation of heavy particles. The paper analyses the feasibility of algae removal used by the combination of air flotation and drocyclonic separation in theory. For testing the combined effect of the two process on algae removal, in this paper, based on the characters of the two process, introduces the improvement and design about the system implementing, includes the bubble generator design and experiment platform design.After accomplish the manufacture, assembly and adjustment of test-bed, we did a lot of detailed comparative analysis. such as the size of separated particle, the result of algae removal used the combination of air flotation and drocyclonic separation and used drocyclonic alone, the effect of intake pressure, and flow volume and inflation pressure. And the experiment worked stably and reliably with the optimization of structure and parameters, thus we realized the best result of algae removal. This prove the feasibility of the combination of air flotation and drocyclonic separation, and establish the basis of theory and practice for the further research and application of algae removal used by ballast water.