304 Development of Ships' Ballast Water Treatment Technology using Underwater Shock Waves

This paper approaches the problem of ballast water treatment in ships. This has been identified as one of the four greatest threats to the world’s oceans. Solutions that have been considered for solving the problem are alternative water treatment technologies. In the case study reported in this paper three major water treatment technologies have been evaluated with the help of twenty-six criteria, quantitative as well as qualitative by using two discrete multicriteria methods, TODIM and THOR 2. The THOR 2 consists of the axiomatic evolution of the THOR method and both THOR 2 and THOR are made available through the THOR Web platform. Five groups of evaluation criteria are then considered: practicality; biological effectiveness; cost/benefit ratio; time frame for the implementation of standards; and environmental impact of the process' sub-products. In this paper a case study on choosing a ballast water treatment technology is presented. Three alternative ballast water management technologies are proposed by experts in the field and are evaluated with the help of twenty-six criteria, quantitative as well as qualitative. Each ballast water management method is described by a list of twenty-six attributes or criteria. After setting the problem in a clear way and consulting different experts, the two separate applications of both TODIM and THOR 2 are performed. What is denoted as Management Method #1 is indeed chosen as the best alternative according to both methods. The conclusion is that those two methods, although conceptually and analytically quite different, lead essentially to the same main results. Two other applications of both TODIM and THOR have indeed confirmed the convergence of results in spite of the conceptual and technical differences between the two methods. This suggests that formulating a decision problem in a correct, clear-cut way can be at least as important as the technical characteristics of the method per se.

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A fuzzy analytical hierarchy process–weighted linear combination decision-making model for prioritization of ballast water treatment technologies by ship owners in Ghana

Proceedings of the Institution of Mechanical Engineers Part M Journal of Engineering for the Maritime Environment ◽

10.1177/1475090218817041 ◽

2018 ◽

Vol 233 (4) ◽

pp. 1276-1286

Author(s):

Isaac Animah

Keyword(s):

Water Treatment ◽

Linear Combination ◽

Analytical Hierarchy Process ◽

Ballast Water ◽

Weighted Linear Combination ◽

Fuzzy Analytical Hierarchy Process ◽

Treatment Technology ◽

Ballast Water Treatment ◽

Treatment Technologies ◽

Hierarchy Process

Giving the ratification of the ballast water management convention, a number of ballast water treatment technologies are emerging in the maritime industry; however, choosing the most appropriate technology has been a big challenge for ship owners because it is a very complex and critical task. The aim of this article is to propose a multi-attribute decision analysis model which integrates the fuzzy analytical hierarchy process and the weighted linear combination method into a more comprehensive approach to select the most appropriate ballast water treatment technology for ship owners. The proposed model consists of 6 attributes (i.e. technological readiness, commercial readiness, operational readiness, seafarer’s skills readiness, biological efficacy readiness and cost of ballast water treatment technologies) and 17 ballast water treatment technologies among which ship owners can choose the best. The fuzzy analytical hierarchy process is used to obtain more realistic weights of the attributes, while the weighted linear combination is applied to prioritize the technologies. To demonstrate the applicability of the model, it is applied to select the best ballast water treatment technology for a ship owner in Ghana. The result shows that the ballast water treatment technology which uses membrane filter is selected as the best. Sensitivity analysis is then carried out to determine the effect of changing attributes’ weights on the final priority rankings of the ballast water treatment technologies. Finally, the model is validated by comparing the obtained results to those from the PROMETHEE model and both results are consistent.

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Ballast Water Treatment Technology: Design, Risk Assessment, and Installation on a Tank Ship

10.5957/smc-2008-027 ◽

2008 ◽

Author(s):

Kevin J. Reynolds ◽

Peter F. Weber ◽

Rudy Mato ◽

Charles Dorchak

Keyword(s):

Risk Assessment ◽

Water Treatment ◽

Ballast Water ◽

Treatment System ◽

Performance Standard ◽

Treatment Technology ◽

Design Assessment ◽

Ballast Water Treatment ◽

Treatment Equipment ◽

Classification Society

This paper outlines the design, assessment, and installation of a prototype ballast water treatment system for a double-hull tank ship. The IMO has established a timetable by which vessels must be equipped with ballast water treatment systems that meet a prescribed performance standard. Tank ship installations are particularly challenging because ballast piping is typically located in spaces defined by classification society rules as hazardous. These same rules do not readily allow the treatment equipment and piping to communicate with these spaces. The treatment system described in this paper has been demonstrated, through a risk assessment, to meet applicable classification society rules. Planned full-scale testing intends to show the operational safety, efficiency, and biological efficacy of this promising technology.

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