Formation of halogenated disinfection by-products during ballast water chlorination

Halogenated disinfection by-products (DBPs) from ballast water treatment have attracted more attention owing to their potential threats to marine ecosystems. Chlorination is widely used in ballast water treatment, in which...

Ballast water management: technology choice comparing TODIM and THOR 2

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.

Determination of the Appropriate Ballast Water Treatment Systems Based on the Voyage Regions for Turkish Shipowners' Companies

Ships must be equipped with ballast water treatment systems to comply with the D-2 standard of the Ballast Water Management Convention. It is required that the adaptation processes of all ships must be completed by September 8, 2024, according to the timetable created by the International Maritime Organization. There are many ballast water treatment systems that shipowners' companies can adopt in the market. The characteristics of the treatment methods used in these systems are different from one another. There are strengths and weaknesses relative to each method. In this process, the choice of one of these ballast water treatment systems is a perplexing problem for shipowners' companies, whose ships have different tonnage and voyage regions. In this context, this study aims to clarify criteria used in the selection of a ballast water treatment system by Turkish shipowners' companies based on the voyage regions of ships. The relative weight of criteria for both international transporting companies and coastal transporting companies are calculated using analytical hierarchy process. Consequently, the most suitable ballast water treatment systems for these two companies are determined using both Technique for Order Preference by Similarity to Ideal Solution and VIKOR, and the factors that play a role in this choice were discussed comparatively.

Systems and Operation of Ballast Water in Ships with the Changing Ballast Water Management Policy

Bio-invasion caused due to ballast water discharge is one of many problems in marine pollution. Countries such as Canada, Brazil, USA and Australia recognized the problems associated with ballasting and deballasting. Countries affected with invasive species formulated specific laws for discharging ballast water in their respective ports. Under the coordination of IMO, countries came together and stressed for globally accepted guidelines that each and every ship has to comply with, while entering any port. In the wake of this, IMO in a convention (2004) on ballast water, proposed guidelines for performing proper ballast water management. This includes ballast water exchange, ballast water treatment, port reception facility, technology approval process, sampling ballast water, analysis methods of ballast water and risk assessment in the convention. Eventually the 2004 convention was found to be inadequate in providing complete elimination of bio invasion. Amendments are made to the 2004 convention over the years for ballast water management. It is found that the member states should share technology among developing countries in establishing sampling and testing laboratories. Region specific sampling analysis and research has to be formulated to understand the bio-invasion based on region and characteristics of different target species in evaluating risk assessment. The D2 standard mentioned in the 2004 convention should be changed from size specific to ‘no organism’ standard in ballast water for discharge. New combination of BWT systems and ‘no ballast’ system with modification to the ship design should be tested, developed and implemented to bring in ecological balance and sustenance in the marine ecosystems.

Analysis of the experimental ballast water treatment system

The object of research is the experimentally created model of the accompanying ballast water treatment systems (BWTS) at the Danube Institute of the National University «Odessa Maritime Academy». (Izmail, Odessa region, Ukraine). The study is aimed at assessing the compliance of ballast water quality standard D-2 ballast water operational cycles by disinfection and purification. One of the most problematic places of the presented research is the renewal (acquisition) of a separate node segmentation of the experimental BWTS with attraction of certain material support (investment). In particular, it is the scaling of BWTS, presentation in the state market of Ukraine, abroad (competition), qualitative assessment, certification at the level of the Ukrainian Sea Ports Administration (USPA), the register of maritime shipping. Elimination of the above «problem-tasks» will contribute to the collective research support, opinion and effective steps of professionals-researchers, in particular, in the maritime industry (experts IMO – International Maritime Organization, professors, academicians TAS – Transport Academy of Sciences). Also, compatible contribution of significant research results to separately oriented projects (European, Ukrainian) with attraction of investors, mentors, maritime industry business. The research used modern practices of design of such accompanying BWTS, referring to innovative methods, methodologies of global production of such structures of famous world brands, for example, Alfa Laval, Wartsila, OceanSaver, Hyde Marine, Industrie de Nora, etc. Researchers have qualitatively and consistently studied the generally accepted series of technological processes for ballast water treatment, observing classical according to the analytical review of literature sources and in the modern coverage (state) of similar stages of ballast water decontamination/cleaning. Qualitative expression of the received result is a number of conducted researches of disinfection/purification of sea outboard water in laboratory conditions on experimental BWTS. Thanks to the latter the reliability of the presented data is provided, which coincide (are identical) with trustworthy, established by the BW quality standard D-2, that are specified in discussion and conclusion of the given work.

Multi-wave UV-photocatalysis system (UVA+UVC+VUV/Cu-N-TiO2) for efficient inactivation of microorganisms in ballast water

Ballast Water Treatment System (BWTS) is a system designed to remove biological organisms from ballast water. However, the existing BWTSs often have problems in practical applications. In this study, a multiwave ultraviolet (UV)-modified TiO2 photocatalyst biological inactivation system (longwave UV, UVA+shortwave UV, UVC+vacuum UV, VUV/Cu-N-TiO2) for microorganism inactivation in ballast water was established. The results showed that the UVA+UVC+VUV/Cu-N-TiO2 system improved the UV light quantum yield and catalyst activity in the photocatalytic reaction and fully utilized the synergistic inactivation effect of Cu-N-TiO2 photocatalyst+ multiwave UV light (UVA, UVC, and VUV) on microorganisms. Compared with 8 other photocatalytic systems, the logarithmic algae removal rate and logarithmic sterilization rate of the UVA+UVC+VUV/Cu-N-TiO2 system increased to 1.78 log and 5.86 log, respectively. The turbidity of the seawater affected the microorganism inactivation to a certain extent. The humic acid concentration should be controlled below 2 mg L−1 for the UVA+UVC+VUV/Cu-N-TiO2 system to inactivate microalgae more effectively. The multiwave UV photocatalytic system could significantly increase the lipid peroxidation products in microbial cells, rapidly reduce superoxide dismutase (SOD) activity, and degrade a large amount of chlorophyll within a short hydraulic residence time (HRT). Severe damage to the microbial cell membrane can destroy the normal functions of cells, resulting in the death of microorganisms. In conclusion, the UVA+UVC+VUV/Cu-N-TiO2 system is a potential new ballast water treatment system.