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Bioremediation was viewed by the participants as a viable strategy 

 for some sediments where they are contained, and where there is a 

 restricted range of contaminants and the remediation processes have 



a long time to work. 



Current bioremediation research programs target individual 

 contaminants. Where particular or individual contaminants are of 

 concern, bioremediation is an appropriate decontamination method. 

 In many cases, however, pollutants in sediments around New York 

 harbor constitute a complex mixture of contaminants, including 

 heavy metals. This raises many questions on how to handle 

 biotransformation of mixed contaminants. 



One consideration with bioremediation is cost-effectiveness. To 

 achieve a significant reduction in sediment decontamination with 

 present bioremediation technology would involve considerable 

 expense including the cost of a treatment facility. No one 

 disputes that for certain compounds, under a specific set of 

 circumstances, bioremediation can provide environmental benefits. 

 However, for some compounds, natural processes can be just as 

 effective as bioremediation. We need to develop a demonstration- 

 scale project to investigate biological methods to remediate New 

 York harbor sediments . 



In general, bioremediation should not be viewed as a panacea for 

 the management of dredged material. Rather, it should be viewed as 

 one technique suitable for specific contaminants which can be 

 contained for long periods of time. 



Chemical and Physical Remediation 



The second conference evaluated a range of technologies using 

 physical and chemical processes to remediate sediments. A wide 

 range of remediation projects are being conducted at the 

 demonstration scale and there is one full-scale separation 

 treatment facility. Most of the U.S. remediation projects are 

 being sponsored by the Environmental Protection Agency through the 

 Assessment and Remediation of Contaminated Sediments (ARCS) 

 program. This program involves bench-scale tests of solvent 

 extraction, thermal desorption and wet-air oxidation techniques 

 with contaminated sediments from Indiana harbor, the Buffalo River 

 and Saginaw Bay. These projects focus primarily on polynuclear 

 aromatic hydrocarbons and polychlorinated biphenyis. 



In Europe, a number of institutions have been developing methods to 

 remediate contaminated sediments over the past ten years . These 

 have led to several small-scale pilot facilities and one full-scale 

 separation facility. Principal methods for remediation involve 

 mechanical separation to separate sand from silt. Other physical 

 separation techniques such as flotation may be effective and, along 

 with heap-leaching techniques, should be investigated further. 



