Sediments treatment

The slow increase in (in the W/0 tanks) with time may represent release of polar metabolites from the bottom sediment. Total in water on day 57 represented 1 and 3% of the total C added to each tank at the start, for the W and W/0 sediment treatments, respectively. In addition, C recovered from the 100 ml water samples decreased from 88% of the total (1 ml samples) on day 3 to 51% on day 57. These results indicate that polar metabolites increased with time since they are not recovered by Sep Paks. Only small amounts of DDE and DDD (7 and 13% of total by day 8 and 15, respectively) were detected in water. 

T0476 Lehigh University, Ground Rubber as a Reactive Permeable Barrier Sorption Media T0479 Limnofix, Inc., Limnofix In Situ Sediment Treatment (LIST)... 

Limnofix In situ Sediment Treatment (LIST) technology is offered by Limnofix, Inc., a Colder Associates Company. The technology allows for the in situ treatment of contaminated sediment in surface waters. LIST enhances bioremediation of organic contaminants oxidizes sediments to control odor, nutrient release, or sulfide toxicity and produces stable marine sediment surfaces via consolidation and flocculation. 

Exposure to explosive-spiked sediments has promoted stimulatory effects on growth of a few species of invertebrates. Significantly increased biomass was observed for C. tentans exposed to RDX, HMX [9], TNT, and TNB [13] in sediment treatments that did not cause significant lethality. Similar effects were observed for II. azteca exposed to TNB or RDX [9] and for TV. arenaceodentata exposed to TNT [15], The mechanisms responsible for hormetic-like concentration-response relationships reported in these studies are unknown, but were speculated to be related to explosives-induced changes in the nutritional status of the sediment, and biochemical and physiological alterations in invertebrates [9],... 

Virkutyte J, SUlanpaa M. (2007). The hindering of experimental strategies on advancement of alkaline front and electroosmotic flow during electrokinetic lake sediment treatment. Journal of Hazardous Materials 143 673-681. 

Techniques for in situ sediment treatment are still in an early stage of development, and the very few methods currently commercially available are usually restricted to situations where the low water levels allow for water flow diversion. Potential in situ treatment methods include biological, chemical, and stabilization processes. The main advantage relies upon avoiding sediment removal and, therefore, the related risk of spreading the contamination. However, technical limitations to the application of in situ treatments still exist, mainly because the effective delivery of such process reagents as substrates, nutrients, and chemicals, as well as mixing with the contaminated material, may be problematic. 

In general, a dramatic reduction of the full-scale performance of electrokinetic sediment treatment may be observed for in situ applications. An evaluation project was developed at a marine embayment used as a former storage and handling area receiving facility effluents and stormwater runoff (USEPA, 2007). The goal of the demonstration was to assess the possibility of reducing the concentrations of Hg,... 

In general, full-scale performance of electrokinetic sediment treatment could be drastically reduced, in case of in situ applications, by heavy corrosion phenomena of the connections between the electrical supply and anodes. 

ECGO is an emerging European technology developed by Dr. Falk Doering for sediment treatment that has been tested in Austria, France, Germany, and Denmark. 

The Duluth demonstration project described in this section targeted PAHs. The demonstration began in 2002-2003 as a simulated in situ sediment treatment pilot project. After 2003, it continued as a project to test ECGO under modified field operating conditions and concluded in 2007 as an ex situ (heaped) treatment test. 

The overall purpose, that is, to investigate the efficacy of the ECGO technology for in situ sediment treatment in a demonstration test in the Erie Pier CDF, Duluth, Minnesota, meant the study required an independent evaluation of the technology in a controlled and monitored test situation, but at a sufficient scale to provide realistic information on costs, effectiveness, and ease of implementation. Hence the specific objectives were identified as... 

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