Ballast water treatment technologies: hydrocyclonic a viable option

Abstract

Many governments, international maritime environmental entities and public health organizations have recognized the environmental, economic and health threats caused by the translocation and release of ballast water. A wide variety of ballast water treatment systems are available at both commercial and under evaluation levels. The available ballast water treatment technologies are reviewed. This work reviews the various types of technologies used in treating ballast water and special attention is given to hydrocyclonic system. Small scale pilot plant hydrocyclone was investigated to identify the behaviour of solid particle separation under the effect of alum addition during the separation. The addition of alum gave a clear improvement on the particle separation but still the use of such a chemical is questionable due to the environmental impact and quantity and time to get effective separation. For particle size greater than 0.8 mm, the removal efficiency ranges from 70 to 86% without alum and from 73 to 90% with alum. The improvement in the removal efficiency is estimated around an average of 4% only. Whereas, for particle size less than 0.3 mm, the removal efficiency ranges from 16.5 to 57% without alum and from 27 to 75% with alum. The addition of alum gave around an average of 15% improvement in the removal efficiency. This concludes that the addition of alum has greater impact on the removal efficiency for particle sizes less than 0.3 mm and less impact on greater particle sizes.