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Hurricanes can introduce metals into coastal systems. Unfortunately, metal concentrations are unknown in many hurricane prone locations. Here we measured vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, molybdenum, cadmium, antimony, barium, lead, and uranium in surface water, sediments, and seagrass (Thalassia testudinum) collected in seagrass beds and marinas around The Abacos, The Bahamas in November 2019, May 2020, and June and December 2021 to establish a post-Hurricane Dorian baseline, assess changes post-storm, and understand bioconcentration in seagrass. Metal concentrations were higher in marinas and several increased over time. Also, metal profiles in sediments became more similar over time. Together, these suggest that metals were impacted by Hurricane Dorian and are either returning to pre-storm conditions or increasing due to recovery-related activities. Thalassia testudinum uptakes most metals more readily from surface water than sediments. Therefore, seagrasses may phytoremediate metals, but also transfer metals to higher trophic levels.
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This content will become publicly available on July 1, 2082
In Situ Remediation of Sediments Contaminated with Organic Pollutants Using Ultrasound and Ozone Nanobubbles
The lower 12·875 km of the Passaic River is heavily contaminated due to industrial activities – specifically heavy metal extraction from chromium-ore-processing plants and production of pesticides and herbicides. Conventional methods for remediating contaminated sediments have limited application due to the tidal action and urban area of the contaminated section of the Passaic River. Hence, this study proposes an in situ technology using ultrasound and ozone nanobubbles to remediate the sediments. Ultrasound is capable of desorbing heavy metals from soil, and ozone can oxidise the released heavy metals to a form that is mobile for ease of extraction. Nanobubbles are used as an effective ozone delivery method for the oxidation of heavy metals. Bench-scale tests were performed to evaluate the feasibility of the proposed technology. Ozone nanobubbles increased the solubility of ozone in water and reduced wastage. Also, due to the high ozone concentrations in water, chromium oxidation increased. A synthetic soil with a grain size distribution similar to that of actual river sediments was artificially contaminated with chromium and used in this research. Test results showed a 97·54% chromium removal efficiency, suggesting the feasibility of the proposed technology for pilot-scale studies.
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- Award ID(s):
- 1634857
- PAR ID:
- 10176380
- Date Published:
- Journal Name:
- Environmental Engineering Science
- ISSN:
- 1557-9018
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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