Ballast Water Management in the Black Sea’s Ports

Study on the effectiveness of membrane separation + N2 deoxidation process for the treatment of bacteria in ballast water

Effects of the membrane separation + N₂ deoxidation process on the abundance and activity of bacteria were examined under two salinity conditions at Yangshan Port, Shanghai, China. Sequencing of 16S rRNA gene amplicons demonstrated a decrease in the diversity and activity of bacteria in fresh water and marine water, with a total removal rate of approximately 63 % and 69 %, respectively. Indicator bacteria decreased to 10 CFU·100 mL^-1, which met the IMO D-2 standard. A total of 13 potential pathogens were detected after treatment, indicating that there is still a risk of pathogenic bacteria invasion in the discharge water, particularly marine bacteria, and that the D-2 standard may be insufficient as a preventive measure against pathogenic bacteria transfer. The results will provide reference for government supervision, and will also be important for monitoring foreign bacteria and technology development.

Ecological impacts of ballast water loading and discharge: insight into the toxicity and accumulation of disinfection by-products

Since the implementation of the International Maritime Organization 2004 regulation, most ships have been equipped with on-dock ballast water treatment. While this method is effective in solving the invasive alien species problem, concerns are raised due to the potential release of disinfection by-products (DBPs) as the result of the chemical treatment. This review paper aims to summarize the history of ballast water management (BWM) and the currently used on-dock technology. Chlorination, oxidation, and ozonation are highlighted as the most currently applied methods to treat ballast water on-dock. This paper then focuses on the potential release of toxic DBPs as the result of the selected corresponding treatment methods. Tri-halo methane, haloacetic acid, and several acetic acid-related compounds are emphasized as toxic DBPs with concentrations reaching more than 10 μg/L. The potential toxicities of DBPs, including acute toxicity, carcinogenicity, genotoxicity, and mutagenicity, to aquatic organisms, are then discussed in detail. Future research directions related to the advanced treatment of DBPs before final discharge and analysis of DBPs in coastal sediments, which are barely studied at present, are suggested to enhance the current knowledge on the fate and the ecological impact of BWM.

Recent progress and challenges facing ballast water treatment - A review

The transoceanic movement of non-indigenous microorganisms and organic and inorganic contaminants through the transfer of ballast water of ocean-going vessels can be considered highly likely. The introduction of contaminants and non-indigenous microorganisms can cause changes in indigenous microorganisms, marine species, and biota, which can create problems for the ecology, economy, environment, and human health. This paper compiles and presents ballast water treatment system concepts, principles of inactivation mechanisms used, and the advantages and challenges of the treatment technologies. In addition, the paper aims to draw attention to the relationship between various organisms and the individual mechanism to be inactivated, including the effect of external factors (e.g., pH, salinity, turbidity) on inactivation efficiency. This review can assist in the choice of a suitable ballast water treatment system, taking into account the water conditions (e.g., pH, temperature, salinity) and indigenous species of the maritime areas where the ships intend to operate. This review also provides information describing the responses of the various organisms to different treatment techniques.