A structural equation modeling approach to assessing the impact of ship characteristics and operational parameters on ballast water treatment efficiency

Articles in Press

Document Type : Original Research Paper

Authors

İskenderun Technical University

10.22059/poll.2025.400685.3078

Abstract

The global spread of invasive aquatic organisms via ballast water discharge poses significant ecological and economic risks. Although various ballast water treatment systems (BWTS) are designed to mitigate this threat, the influence of ship-specific and operational parameters on treatment performance remains insufficiently understood. This study applies Structural Equation Modeling (SEM) to evaluate relationships among ship characteristics (gross tonnage, length, width), treatment system operational parameters (rated capacity, retention time, flow rate, total volume), and biological outcomes (concentrations of organisms ≥50 µm and 10–50 µm). Data were obtained from 59 International Maritime Organization (IMO)-compliant commissioning test reports collected during discharge via dedicated sample ports under IMO G2 guidelines. Organism concentrations were determined using second-generation Adenosine triphosphate (ATP) analysis, with thresholds aligned to the IMO D-2 standard.

Initial one-way ANOVA tests revealed no significant differences in organism concentrations across ship types or treatment technologies. Multiple regression analyses identified modest linear relationships between certain ship or operational variables and biological outcomes but also showed inter correlations among predictors that could obscure their individual effects. To address these dependencies and investigate potential indirect pathways, SEM was employed. The final model achieved good and indicated that larger ships generally possessed greater treatment and operational capacity, which was associated with reduced concentrations of organisms in the 10–50 µm size class. No significant effect was observed for organisms ≥50 µm. These results highlight the need to align BWTS capacity and hydraulic exposure with vessel scale, while suggesting that supplementary strategies may be required to effectively control larger organisms.

Keywords

Main Subjects

Pollution

Articles in Press, Accepted Manuscript
Available Online from 21 December 2025

Files

Share

How to cite

Statistics