Ballast Water Treatment Performance Evaluation under Real Changing Conditions

Abstract

We conducted a shipboard ballast water test using seawater of extreme turbidity collected from Shanghai Port (China) (>300 mg total suspended solids (TSS)/L), and normal seawater collected in other ports (<100 mg TSS/L). All three types of International Maritime Organization (IMO)-approved ballast water management system (BWMS) tested failed to properly operate because of filter clogging or insufficient generation of oxidants under near-fresh water conditions with extremely high concentration of suspended solid during ballasting. It was also found that the number of microorganisms increased with longer ballast water retention time, with higher numbers in the treated discharge water. The results suggest that when operating a BWMS involving a filter unit in areas with water having high concentrations of suspended solids, the filter unit should be used during ballast water discharge, rather than during ballasting. This method has the advantage of removing ≥50 µm organisms at discharge that could not be removed by a filter during ballasting. For ballast water retained for long storage times, the results suggest the use of BWMSs involving UV units or electrolysis during deballasting. In addition, BWMSs involving electrolysis units provide the opportunity to maintain residual total residual oxidant (TRO) levels, using a partial ballast tank. Although the BWMSs tested are a small subset of the large number of IMO-approved BWMSs, the results demonstrate that there is a significant gap between the technology currently available and capacity to meet IMO and US Coast Guard standards.

Anthropogenic Modifications to Estuaries Facilitate the Invasion of Non-Native Species

“…In order to overcome these challenging conditions properly, the assessment and validation of ballast water treatment systems that can efficiently overcome these two factors (biotic and abiotic) is encouraged. Thus, it should involve a "worst case scenario" that could occur in real water conditions [18,73]. Additionally, the development of efficient ballast water management systems in these scenarios would also benefit some related industries, such as aquaculture, which is also, potentially, affected by possible spread of organisms resulting from an inadequate ballast water management [61,70].…”

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

“…Thousands of marine species that are carried away during the processes of applying and removing ballast water, resulting in an exchange of organisms in the area, can disrupt the balance of marine ecosystems in certain areas ( Demann and Wegner, 2019 ; Hess-Erga et al., 2019 ; Jang et al., 2020 ). The mixing of native organisms that have long inhabited an area with alien organisms can also cause competition ( Saburova et al., 2022 ).…”

“…The aforementioned treatment methods achieved high removal efficiency, as detailed by many researchers. Chlorination achieved 75%–99% efficiency in removing various organisms in ballast water ( Ichikawa et al., 1992 ; Bolch and Hallegraeff, 1993 ; Gray et al., 2006 ), electrochemical treatments had plankton removal efficiency >99% ( Dang et al., 2003 ; Jang et al., 2020 ), oxidation with various oxidants removed 97%–99% of various organisms ( Wright et al., 2007 ; de Lafontaine et al., 2008 ), and ozonation may remove up to 99% of various organisms in ballast water ( Oemcke and Van Leeuwen, 2005 ; Perrins et al., 2006 ). Despite their great and reliable efficiencies, a concern was raised due to the environmental effect caused by the application of disinfection, known as DBPs ( Delacroix et al., 2013 ; Shah et al., 2015 ; Ziegler et al., 2019 ).…”

“…Some articles have already studied and reviewed the implementation of IMO 2004 regulation to the current ballast water treatment in cargo ships ( Chen et al., 2021 ; Jang et al., 2020 ; Outinen et al., 2021 ). The most used technologies for on-dock ballast water treatment include chlorination, electrochemical, oxidation, and ozonation ( Summerson et al., 2019 ).…”

LED Module Calibration Strategy to Improve Measurement Accuracy of TRO Concentration

“…The electrolysis of water is the most widely used because of its cost and effectiveness [8]. Electrolysis of ballast water produces Total Residual Oxidant (TRO) capable of sterilizing microorganisms [9,10]. The electrolysis method BWMS must control the current to generate an appropriate TRO to prevent sterilization and excessive disinfection by-products in accordance with IMO D-2 regulations.…”