Refine search
Results 2201-2210 of 7,250
Potential sources and toxicity risks of polycyclic aromatic hydrocarbons in surface sediments of commercial ports in Taiwan
2022
Chen, Chih-Feng | Ju, Yun-Ru | Lim, Yee Cheng | Wang, Ming-Huang | Albarico, Frank Paolo Jay B. | Chen, Chiu-Wen | Dong, Cheng-Di
The accumulation of pollutants in the semi-enclosed waters of ports has long been a concern. This study assessed the pollution status, sources, and toxicity risks of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments of 7 major ports in Taiwan. Total PAHs concentrations in sediments ranged between 8.4 and 572.5 ng/g dw, with an average of 112.4 ± 136.5 ng/g dw. The 3- and 4-ring PAHs (63 %) were the major constituents of PAHs in the sediments. Diagnostic ratios and positive matrix factorization analyses indicated that PAHs in sediments were mainly contributed by biomass combustion (45.0 %), coal combustion (31.5 %), and vehicle emissions and related fossil fuels (23.5 %). The results of ecological risk assessment showed a low–medium risk of PAHs in the sediments outside the port, whereas most of the sediments within the port presented a medium–high risk. An assessment of the possible human health risks indicated that PAHs were present at acceptable levels.
Show more [+] Less [-]Advances in Membrane Bioreactor: High Performance and Antifouling Configurations
2022
Siagian, Utjok Welo Risma | Khoiruddin, Khoiruddin | Ting, Yen Peng | Boopathy, Ramaraj | Wenten, I Gede
PURPOSE OF REVIEW: This paper reviews recent advances in a membrane bioreactor (MBR) and focuses on the features and performance of MBR configurations. Special attention is given to MBR configurations developed for improving pollutant removal and fouling control. RECENT FINDINGS: The first development discussed in this review is related to pollutant removal. Modified MBR configuration can enhance pollutant removals, such as those observed in baffled, osmotic, aerobic granular sludge, and electric field-assisted MBR. In addition, fouling is still the major problem in MBR applications. Fouling affects membrane performance stability as well as operational and capital costs. Several new MBR configurations have been developed to address fouling issues. By using dynamic membrane and free-moving particles, these new configurations make MBR operation more stable with fewer cleaning operations. In addition, lower cleaning frequency will decrease operational expenditure and capital investment. Due to their unique features, newly developed MBR configurations are proved to display high pollutant removal in wastewater treatment. Meanwhile, MBR with dynamic membranes and moving particles can decrease membrane fouling due to mechanically induced shear with lower energy consumption than shear by conventional aeration.
Show more [+] Less [-]Microplastics in different tissues of caught fish in the artificial reef area and adjacent waters of Haizhou Bay
2022
Gao, Shike | Li, Zheng | Wang, Na | Lu, Yanan | Zhang, Shuo
In recent years, the microplastics (MPs) pollution in the offshore of microplastics has gradually become a concerning topic, and the understanding the accumulation of MPs in different tissues of organisms is also an important aspect. MPs can easily affect target tissues and transport related chemicals to humans through the food chain. MPs in the gills and guts of fish in the artificial reef area of Haizhou Bay and adjacent waters were detected in this study. The results showed that MPs were ubiquitous in the gills and guts of 26 species, with average quantities of 3.54 ± 2.14 pieces/fish and 3.00 ± 2.63 pieces/fish, respectively. More than 99% of the plastics were MPs that were less than 5 mm in diameter, with blue fiber being the most common. The number and quantity of MPs in gills were higher than those in guts in different habitat types, living water layers and feeding habits of fish. At the community level, as the body length and body weight increased, the quantity of MPs in the gills and guts showed a slight decreasing trend, and the correlation was not strong (P > 0.05). With increasing trophic levels (TLs), MPs were biomagnified in the guts (Trophic magnification factor, TMF = 1.37), but no change occurred in the gills (TMF = 1.00). We believe that biomagnification of MPs should be obtained by comparing the quantity of MPs in whole organisms rather than only in specific tissues before such conclusions can be defined. We recommend that periodic marine monitoring programs be implemented, as well as research into smaller MPs and even nanoplastics, to assess from the perspective of water, sediments, organisms and ecotoxicology, which will provide useful information for MPs pollution in artificial reefs and help to improve the MPs pollution database in China.
Show more [+] Less [-]Oceanic plastic pollution caused by Danish seine fishing in Norway
2022
Syversen, Tore | Lilleng, Grethe | Vollstad, Jørgen | Hanssen, Bård Johan | Sønvisen, Signe A.
Wear and tear on fishing gear is a sparsely investigated source of microplastic pollution in the sea. In Norway, Danish seine ropes and trawls are the fishing gears that contribute most to this pollution. The main reason for this pollution is that the seine ropes are dragged along the seabed over a considerable distance, creating a friction force that results in high ropes wear. This note reports the findings after examining the wear of Danish seine ropes used in Norwegian fisheries. The results show that, in Norway alone, an average of 77 to 97 tons of plastic will be added to the sea annually due to this specific fishing gear. Aggregated to include all fly dragging, anchor seining, and pair seining globally, this number is estimated to be about 311 tons per year.
Show more [+] Less [-]Occurrence, allocation and geochemical controls for mercury in a typical estuarine ecosystem: Implications for the predictability of mercury species
2022
Mao, Lulu | Ren, Wenbo | Liu, Xitao | Lin, Chunye | Wang, Zongxing | Wang, Baodong | Xin, Ming | He, Mengchang | Ouyang, Wei
In this study, surface seawater, bottom seawater and surface sediments were collected from the Yellow River Estuary Area (YREA) and the Laizhou Bay (LB) to investigate the occurrence, spatial distribution and geochemical control factors for total mercury (THg) and methylmercury (MeHg) in different phases. The geochemical characteristics of seawater and sediments suggested significant variances in the YREA and the LB. The high contamination of Hg in the YREA showed the discharge of the Yellow River (YR) contributed significantly to the Hg contamination in the LB. The partial least squares regression (PLSR) model was utilized to explore the complicated interactions between geochemical controls and methylation potentials in different phases. Although the ecological risk (ER) of Hg was not significant in this study area, the higher values of ER in the YREA suggested that the YR was the primary Hg contributor to LB. Therefore, the potential Hg risk should not be ignored.
Show more [+] Less [-]Evolution of polycyclic aromatic hydrocarbons in the surface sediment of southern Jiaozhou Bay in northern China after an accident of oil pipeline explosion
2022
Ding, Huiping | Lan, Jie | Yao, Shuo | Zhang, Dahai | Han, Bin | Pan, Gang | Li, Xianguo
The 2013 “Qingdao oil pipeline explosion” contaminated about 2.5 km of shoreline in the Jiaozhou Bay area and aroused widespread concern because of the serious casualties even though it was not the most severe oil-spill contamination in China. To evaluate the long-term impact, we collected thirty-three surface sediment samples after 3 years of the accident, with sixteen polycyclic aromatic hydrocarbons (PAHs) detected. Spatial-temporal variation in PAHs revealed that a minimal impact might still be present after 3 years. Source analysis combined with a one-way ANOVA showed that pyrolytic sources were consistently predominant. The environmental impact was already minimal 3 years later and negligible thereafter. Although the cancer risk has decreased over the years, there has always been a potential hazard to human for specific occupation, with all of the risk values exceeded 10⁻⁶. This study offers a reference for assessing the long-term impact of oil spills in similar bay areas.
Show more [+] Less [-]Development of an offshore response guidance tool for determining the impact of SSDI on released gas and benzene from artificial subsea oil well blowout simulations
2022
Socolofsky, Scott A. | Jun, Inok | Boufadel, Michel C. | Liu, Ruixue | Lu, Youyu | Arey, J Samuel | McFarlin, Kelly M.
We present an analysis of 2225 simulations of artificial oil well blowouts in nearshore and offshore waters of Newfoundland, Canada. In the simulations, we coupled the VDROP-J and TAMOC models to simulate the fate and transport of oil and gas from the release to the sea surface. Simulations were conducted with and without subsea dispersant injection. We analyzed the simulation database to quantify the mass fraction of oil and gas that surfaces, the mass fraction of released benzene that surfaces, and the horizontal offset to the surfacing zone. These data are also synthesized to yield empirical correlations to predict these output metrics from key input parameters. These correlations are summarized in an excel spreadsheet that allows rapid evaluation of spill dynamics with minimal initial knowledge of spill details. We call this tool an offshore response guidance table, which allows exploration of spill dynamics under diverse spill and response options.
Show more [+] Less [-]Evaluation of microplastic and marine debris on the beaches of Niterói Oceanic Region, Rio De Janeiro, Brazil
2022
da Silva, Elaine Ferreira | do Carmo, Dirlane de Fátima | Muniz, Marcelo Costa | dos Santos, Camila Américo | Cardozo, Bárbara Barroso Issa | Costa, Daniel Miranda de Oliveira | dos Anjos, Roberto Meigikos | Vezzone, Mariana
The characterization of microplastics helps to improve sustainable management practices in aquatic ecosystems impacted by plastic litter. Plastic litter and microplastics from four ocean beaches in the Niterói municipality was evaluated in winter and summer. The collection and preparation of microplastic sample procedures followed on the protocol developed by the RLA7025 Project of the International Atomic Energy Agency. Marine debris followed to the United Nations Environment Program protocol. The polymer was characterized by ATR-FTIR technique.The Clean Coast Index was used to determine the degree of dirt on the beaches. Polyethylene (43%) and Polystyrene (52%) were the most abundant microplastics. The plastic is the most abundant category; representing 85% in winter and 73% in summer.The main sources are related to the consumption of drinks and food. These results emphasize the importance of reverse logistics and the value chain for packaging material and the need for effective actions managing solid waste.
Show more [+] Less [-]Multicompartmental analysis of POPs and PAHs in Concepciόn Bay, central Chile: Part II – Air-sea exchange during Austral summer
2022
Pozo, Karla | Gomez, Victoria | Tucca, Felipe | Galbán-Malagón, Cristóbal | Ahumada, Ramón | Rudolph, Anny | Klánová, Jana | Lammel, Gerhard
Air-sea exchange of POPs and PAHs was assessed in Concepción Bay during January, summer 2015. Results showed low levels, in air and water, for POPs (1–20 pg m⁻³, and 6–50 pg L⁻¹, respectively) and for ΣPAHs (1–2 ng m⁻³ and 1–2 ng L⁻¹, respectively). The highest levels were found for PBDEs (200–20,000 pg L⁻¹) in the water samples (3-fold times higher than PCBs and OCP) and PBDE209 accounted for 90% of total ΣPBDEs. Air–sea exchange fluxes (ng m⁻² d⁻¹) were low in general, with exception of PBDEs showing values up to 40,000 ng m⁻² d⁻¹. Net deposition was found for PAHs, HCB and some PBDEs; while, BDE99, and BDE100 showed net volatilization. These findings contribute with new data of diffusive air-sea exchange on the southern hemisphere Pacific coast.
Show more [+] Less [-]Quantification and characterization of plastics in near-shore surface waters of Atlantic Canada
2022
Smith, Ariel | Liboiron, Max | Charron, Louis | McIntyre, Jessie | Hawkins, Kaitlyn | McLean, Katie | Peddle, Sheldon | Moore, Greg | Walzak, Mary Jane | Goodman, Alexa | Fulton, Leah | Fredericks, Shanna | Nodding, Brooke
Plastics are a ubiquitous pollutant in the marine environment. Despite growing concerns, quantitative and qualitative data on microplastics in aquatic and marine environments of Atlantic Canada is just emerging. Surface water plastics were measured and categorized by morphology (thread, microfibre, fragment, foam, film, pellet, and microbead) in two locations in Nova Scotia and one in Newfoundland and Labrador, Canada. All sites within the three locations contained plastic with an average abundance of 9669 items/km². Most plastics (68 %) were sized as microplastics (0.425–5 mm), and plastic fragments were the most common morphological type. Polyethylene accounted for a third (30 %) of all particles found across all three locations, followed by polypropylene (23 %). Results can inform future research for community-based environmental groups, government, and academia.
Show more [+] Less [-]