Improved Z-number and fault tree analysis to predict the risk of air pollution due to ship boiler operation.

Ships present a significant source of air pollution, contributing to environmental degradation and posing health risks. Boilers are a significant part of the vessels in which the water is heated to evaporate and generate steam. The boilers emit pollutants such as hazardous air pollutants (HAPs), particle pollution, and volatile organic compounds (VOC). This paper conducts an extended risk analysis for air pollution due to boiler operation on ships. An improved Z-numbers theory and Fault Tree Analysis (FTA) are adopted to predict risk. Whilst improved Z-number theory is capable of handling uncertainties inherent in risk assessment, the FTA presents systematically the causal relationships among various factors contributing to the risk of air pollution on ships. The findings show that the failure probability of air pollution during ship boiler operation is 2.08E-05 and BE-12 is the most significant event. Results provide valuable data to maritime stakeholders in fostering environmentally sustainable practices.

Sustainability in maritime transport: Selecting ballast water treatment for a bulk carrier.

The study provides a comprehensive assessment of ballast water treatment systems (BWTS) selection regarding crucial parameters such as energy efficiency, fuel consumption, and CO2 emissions. The focus of the study is investigating the environmental impacts of BWTS and how these impacts can be considered in decision-making processes. In this context, it comprehensively analyzes the importance of decision-making parameters and the environmental consequences of BWTS applications. The potential impacts of the system on the sustainability of the maritime industry are highlighted. In this context, seven different BWTSs for a bulk carrier of 83,000 deadweight tonnes are evaluated using Analytical Hierarchy Process (AHP) and Preference Ranking Technique by Similarity to Ideal Solution (TOPSIS). According to the analysis, Operational Expenditure (0.314508), Capital Expenditure (0.249515), and Capacity (0.159952) are the most critical factors. Among the seven systems analysed, product G (0.8561137) emerges as the most suitable option. The analysis represents 3% of total emissions (456.5 tonnes CO2) and highlights the impact of BWTS on CO2 emissions. The results underline the need for innovative approaches aimed at ensuring the long-term sustainability of the maritime industry.