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Title: Removal of Heavy Metals and Organic Contaminants from Aqueous Streams by Novel Filtration Methods

Abstract

The removal of hazardous waste, generated by the dismantling of nuclear weapons is a problem that requires urgent attention by the US Department of Energy. Low levels of radioactive contaminants combined with organic solvent residues have leaked from aging containers into the soil and underground water in the surrounding area. Due to the complexity of the problem, it is evident that traditional adsorption methods are ineffective, since the adsorbent tends to saturate with the aqueous component. It has become apparent that a much more aggressive approach is required which involves the use of specially designed materials. We have investigated the potential of solids that combine high surface area/high pore volume and high electrical conductivity, a rare combination of properties found in a single material. In this program we examined the potential of newly developed materials for the trapping of organic solvents within specially engineered cavities without allowing the material to become saturated with water. Catalytically grown carbon nanofibers are a set of novel structures that are produced by the decomposition of selected carbon-containing gases over metal particles. These materials consist of extremely small graphite platelets stacked in various orientations with respect to the fiber axis. Such an arrangement results inmore » a unique structure that is composed of an infinite number of extremely short and narrow pores, suitable for sequestering small molecules. In addition, when the graphene layers are aligned parallel to the fiber axis, an unusual combination of high surface area and low electrical resistivity solids are attained. We have attempted to capitalize on this blend of properties by using such structures for the selective removal of organic contaminants from aqueous streams. Experimental results indicate that nanofibers possessing a structure in which the graphite platelets are aligned perpendicular to the fiber axis and possessing a high degree of structural perfection exhibit superior selective adsorption properties with respect to removal of alcohols from aqueous medial over that displayed by active carbon. Furthermore, we have attempted to take advantage of the high electrical conductivity as well as the high availability of edges, and we have used these materials for the removal of metal ions from solution. Preliminary results indicate that graphite nanofibers can, in the presence or absence of an applied electric field, capture metal ions from solution. In addition, it has been found that certain types of nanofibers can absorb substantial amounts of water both in the vapor and liquid phase.« less

Authors:
Publication Date:
Research Org.:
USDOE Idaho Operations Office, Idaho Falls, ID; Northeastern University, Boston, MA (US)
Sponsoring Org.:
USDOE Office of Energy Research (ER) (US)
OSTI Identifier:
765175
Report Number(s):
DOE/ER/14688
TRN: US0100220
DOE Contract Number:  
FG07-96ER14688
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1 Aug 2000
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; ELECTRIC CONDUCTIVITY; ELECTRIC FIELDS; FILTRATION; NUCLEAR WEAPONS; ORGANIC SOLVENTS; REMOVAL; SURFACE AREA; RADIOACTIVE CONTAMINANTS; ORGANIC SOLVENT RESIDUES; SOIL; WATER; CARBON NANOFIBERS; GRAPHITE PLATELETS; FIBER AXIS; ELECTRICAL RESISTIVITY; AQUEOUS STREAMS; ADSORPTION

Citation Formats

Rodriguez, N M. Removal of Heavy Metals and Organic Contaminants from Aqueous Streams by Novel Filtration Methods. United States: N. p., 2000. Web. doi:10.2172/765175.
Rodriguez, N M. Removal of Heavy Metals and Organic Contaminants from Aqueous Streams by Novel Filtration Methods. United States. doi:10.2172/765175.
Rodriguez, N M. Tue . "Removal of Heavy Metals and Organic Contaminants from Aqueous Streams by Novel Filtration Methods". United States. doi:10.2172/765175. https://www.osti.gov/servlets/purl/765175.
@article{osti_765175,
title = {Removal of Heavy Metals and Organic Contaminants from Aqueous Streams by Novel Filtration Methods},
author = {Rodriguez, N M},
abstractNote = {The removal of hazardous waste, generated by the dismantling of nuclear weapons is a problem that requires urgent attention by the US Department of Energy. Low levels of radioactive contaminants combined with organic solvent residues have leaked from aging containers into the soil and underground water in the surrounding area. Due to the complexity of the problem, it is evident that traditional adsorption methods are ineffective, since the adsorbent tends to saturate with the aqueous component. It has become apparent that a much more aggressive approach is required which involves the use of specially designed materials. We have investigated the potential of solids that combine high surface area/high pore volume and high electrical conductivity, a rare combination of properties found in a single material. In this program we examined the potential of newly developed materials for the trapping of organic solvents within specially engineered cavities without allowing the material to become saturated with water. Catalytically grown carbon nanofibers are a set of novel structures that are produced by the decomposition of selected carbon-containing gases over metal particles. These materials consist of extremely small graphite platelets stacked in various orientations with respect to the fiber axis. Such an arrangement results in a unique structure that is composed of an infinite number of extremely short and narrow pores, suitable for sequestering small molecules. In addition, when the graphene layers are aligned parallel to the fiber axis, an unusual combination of high surface area and low electrical resistivity solids are attained. We have attempted to capitalize on this blend of properties by using such structures for the selective removal of organic contaminants from aqueous streams. Experimental results indicate that nanofibers possessing a structure in which the graphite platelets are aligned perpendicular to the fiber axis and possessing a high degree of structural perfection exhibit superior selective adsorption properties with respect to removal of alcohols from aqueous medial over that displayed by active carbon. Furthermore, we have attempted to take advantage of the high electrical conductivity as well as the high availability of edges, and we have used these materials for the removal of metal ions from solution. Preliminary results indicate that graphite nanofibers can, in the presence or absence of an applied electric field, capture metal ions from solution. In addition, it has been found that certain types of nanofibers can absorb substantial amounts of water both in the vapor and liquid phase.},
doi = {10.2172/765175},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {8}
}