Filtration as a Ballast Water Treatment Measure

Abstract

Filtration has been proposed as a ballast treatment in both shipboard and shore-based applications. Operated at the port of origin, filtration can dramatically reduce densities of larger plankton and other taxa in the ballast intake steam without generating chemical or thermal residuals. It also could enhance or complement performance of biocidal treatment systems. Pilot scale tests suggest that filtration is already operationally and economically feasible for some classes of ships, including many of concern in the global translocation of organisms, such as container and passenger ships. Applications to larger ships with higher flow-rates could become feasible with design improvement to today's filter technology. This chapter describes current uses of filtration on ships, types of filtration proposed for the ballast treatment application, performance evaluations of filtration as a ballast treatment, filtration as a componenet in compount treatment systems, pore size considerations, and the merits of filtration versus cyclonic separation as a primary treatment method.