Method Development for Low-Concentration PAHs Analysis in Seawater to Evaluate the Impact of Ship Scrubber Washwater Effluents

Abstract

A naval ship’s exhaust gas scrubber may discharge polycyclic aromatic hydrocarbons (PAHs) into seawater. Due to the high lipophilicity and low water solubility of PAHs, their concentrations in seawater are extremely low, making them difficult to detect or accurately determine. To accurately assess the impact of scrubber washwater effluent on the PAHs concentration of seawater, appropriate analysis methods must be established. In this study, a large-volume pre-concentration water sampler was used onboard to concentrate PAHs in surface seawater (100 L) from four sites offshore of southern Taiwan. The quantitative and qualitative analysis of dissolved PAHs in seawater and quality control samples were implemented using a GC/MS system with the aid of internal and surrogate standards. Results showed that the field and equipment blank samples of quality control samples were lower than twice the detection limit. The detection limit of individual PAHs is between 0.001 (naphthalene, NA) and 0.014 ng/L (dibenzo[a,h]anthracene, DBA), which meets the requirements for evaluating PAHs in seawater (that is, less than the maximum permissible concentrations (MPCs)). The concentration of total PAHs (TPAHs) in the four seawater samples ranged from 2.297 to 4.001 ng/L and had an average concentration of 3.056 ± 0.727 ng/L. The concentrations of 16 PAHs were determined in each seawater sample, indicating that the analytical method in this study is suitable for the determination of low-concentration PAHs in seawater. Phenanthrene (PHE) is the most dominant compound in seawater samples accounting for 59.6 ± 12.6% of TPAHs, followed by fluorine (FL) accounting for 8.5 ± 3.7%. The contribution of high-ring PAHs to TPAHs is not high (0.5–9.2%), but the observed concentrations can cause a higher risk to aquatic organisms than low-ring PAHs. The diagnostic ratio showed that the sources of PAHs in the seawater collected offshore of southern Taiwan may include mixed sources such as petrogenic, petroleum combustion, and biomass combustion. The results can be used for regular monitoring, which contributes to pollution prevention and management of the marine environment.

Mitigation of Ship Emissions: Overview of Recent Trends

“…Therefore, the precautionary principle calls for limiting the discharge of washwater along coastal areas . Unfortunately, even within IMO discharge limits for coastal areas, the intensity of economic traffic directly impacts the chronic accumulation of hazardous materials jeopardizing the resilience of biotic communities and their ecosystems. , Some studies on the discharge water of scrubbers by types of fuel, engine, and scrubber are summarized in Table S2 in the Supporting Information. ,,− …”

Remediation of water contaminated with polycyclic aromatic hydrocarbons using liquid phase plasma: Influence of electrical discharge condition

“…Though studies on the harmful effects and analysis of PAHs in scrubber effluent have been recently introduced, a suitable process to degrade them remains undeveloped yet (Thor et al, 2021;Chen et al, 2022;Ji et al, 2022). Therefore, LPP was employed to degrade PAHs in real scrubber effluent and the performance was assessed.…”

“…In the field of marine environment, the number of studies on the hazards of PAHs from exhaust gas cleaning system (EGCS or scrubber) effluents has recently increased (Chen et al, 2022;Ji et al, 2022;Ytreberg et al, 2022). As the International Maritime Organization (IMO) has tightened the limits of sulfur emission (MARPOL, 2008), the number of vessels with scrubbers has sharply increased from 12 in 2011 to 4047 in 2020 (ICCT website).…”

Electrochemical Properties of Super Austenite Stainless Steel with Temperature in a Green Death Solution

“…However, the device faced corrosion problems due to the operating environment, including high temperatures and washing water [3]. Experts have devised surface treatments, corrosion inhibitors, and material developments as corrosion prevention measures for exhaust gas aftertreatment devices at power plants [4].…”