Long-Term Recovery of PCB-Contaminated Sediments at the Lake Hartwell Superfund Site:  PCB Dechlorination. 1. End-Member Characterization

2005 ◽  
Vol 39 (10) ◽  
pp. 3538-3547 ◽  
Author(s):  
Victor S. Magar ◽  
Glenn W. Johnson ◽  
Richard C. Brenner ◽  
John F. Quensen ◽  
Eric A. Foote ◽  
...  
Keyword(s):  
Contaminated Sediments ◽  
Superfund Site ◽  
Lake Hartwell ◽  
Pcb Dechlorination

Long-Term Recovery of PCB-Contaminated Sediments at the Lake Hartwell Superfund Site:  PCB Dechlorination. 2. Rates and Extent

2005 ◽  
Vol 39 (10) ◽  
pp. 3548-3554 ◽  
Author(s):  
Victor S. Magar ◽  
Richard C. Brenner ◽  
Glenn W. Johnson ◽  
John F. Quensen
Keyword(s):  
Contaminated Sediments ◽  
Superfund Site ◽  
Lake Hartwell ◽  
Pcb Dechlorination

Long-Term Recovery of PCB-Contaminated Surface Sediments at the Sangamo-Weston/Twelvemile Creek/Lake Hartwell Superfund Site

2004 ◽  
Vol 38 (8) ◽  
pp. 2328-2337 ◽  
Author(s):  
Richard C. Brenner ◽  
Victor S. Magar ◽  
Jennifer A. Ickes ◽  
Eric A. Foote ◽  
James E. Abbott ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Superfund Site ◽  
Lake Hartwell

scholarly journals Diagenetic formation of uranium-silica polymers in lake sediments over 3,300 years

2021 ◽  
Vol 118 (4) ◽  
pp. e2021844118
Author(s):  
Pierre Lefebvre ◽  
Alkiviadis Gourgiotis ◽  
Arnaud Mangeret ◽  
Pierre Sabatier ◽  
Pierre Le Pape ◽  
...  
Keyword(s):  
Contaminated Sediments ◽  
Mining Areas ◽  
Subsurface Environments ◽  
Geochemical Reactivity ◽  
High Silica ◽  
Long Term Behavior ◽  
The Impact ◽  
X Ray Absorption

The long-term fate of uranium-contaminated sediments, especially downstream former mining areas, is a widespread environmental challenge. Essential for their management is the proper understanding of uranium (U) immobilization mechanisms in reducing environments. In particular, the long-term behavior of noncrystalline U(IV) species and their possible evolution to more stable phases in subsurface conditions is poorly documented, which limits our ability to predict U long-term geochemical reactivity. Here, we report direct evidence for the evolution of U speciation over 3,300 y in naturally highly U-enriched sediments (350–760 µg ⋅ g−1 U) from Lake Nègre (Mercantour Massif, Mediterranean Alps, France) by combining U isotopic data (δ238U and (234U/238U)) with U L3-edge X-ray absorption fine structure spectroscopy. Constant isotopic ratios over the entire sediment core indicate stable U sources and accumulation modes, allowing for determination of the impact of aging on U speciation. We demonstrate that, after sediment deposition, mononuclear U(IV) species associated with organic matter transformed into authigenic polymeric U(IV)–silica species that might have partially converted to a nanocrystalline coffinite (UIVSiO4·nH2O)-like phase. This diagenetic transformation occurred in less than 700 y and is consistent with the high silica availability of sediments in which diatoms are abundant. It also yields consistency with laboratory studies that proposed the formation of colloidal polynuclear U(IV)–silica species, as precursors for coffinite formation. However, the incomplete transformation observed here only slightly reduces the potential lability of U, which could have important implications to evaluate the long-term management of U-contaminated sediments and, by extension, of U-bearing wastes in silica-rich subsurface environments.

scholarly journals Sediment Mining

2017 ◽  
Author(s):  
Homayoun Fathollahzadeh ◽  
Fabio Kaczala ◽  
Amit Bhatnagar ◽  
William Hogland
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Contaminated Sediments ◽  
Management Options ◽  
Metals Recovery ◽  
Environmental Footprints ◽  
Valuable Metals ◽  
Short And Long Term ◽  
Near Future

The main dilemma of contaminated sediments has been the proper management with reduced environmental footprints. Furthermore, by considering the fact that global warming and climate change may complicate the choice of management options, finding appropriate solutions become extremely critical. In the present work, mining of contaminated sediments to recover valuable constituents such as metals and nutrients is proposed as sustainable strategy, both through enhancing resilience of ecosystem and remediation. Contaminated sediments in the Oskarshamn harbor, southeast of Sweden were collected and analyzed through a modified sequential extraction in order to evaluate the feasibility of metals recovery. The results have shown that among different metals present in the sediments, Cu and Pb can be initially considered as economically feasible to recover. The shifting in the concept of dredging and further remediation of contaminated sediments towards sediment mining and recover of valuable metals can be considered in the near future as a sustainable strategy to tackle contaminated harbor/ports areas. However, it must be highlighted that short and long-term environmental impacts related to such activities should be addressed.

Comparative evaluation of bioremediation techniques on oil contaminated sediments in long-term recovery of benthic community health

2019 ◽  
Vol 252 ◽  
pp. 137-145 ◽  
Author(s):  
Changkeun Lee ◽  
Seongjin Hong ◽  
Junsung Noh ◽  
Junghyun Lee ◽  
Seo Joon Yoon ◽  
...  
Keyword(s):  
Community Health ◽  
Benthic Community ◽  
Comparative Evaluation ◽  
Contaminated Sediments

Risk assessment and technological options for contaminated sediments — a geochemical perspective

1995 ◽  
Vol 46 (1) ◽  
pp. 113 ◽  
Author(s):  
U Forstner
Keyword(s):  
Contaminated Sediments ◽  
Risk Assessments ◽  
Diverse Range ◽  
Biological Criteria ◽  
Future Risk ◽  
Priority Needs ◽  
And Storage ◽  
Technological Options ◽  
Geochemical Engineering

The effective long-term remediation of contaminated sediments presents a particular challenge, since the large volume and the often diverse range of contaminants in these materials makes many of the traditional remediation techniques uneconomic. Future risk assessments of contaminated sediments should focus on assessing possible chemical changes in the stored sediment (e.g. redox changes and acid production) that could lead in the long term to contaminant remobilization. New biological criteria of contaminated sediments are also needed. These risk assessments must be undertaken with the potential remediation methods in mind. Priority needs to be given to the application of new geochemical engineering techniques, including chemical stabilization by additives and storage under permanent anoxic conditions, that optimize the long-term chemical stability of contaminated sediments.

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