Grantee Research Project Results

1999 Progress Report: Molecular Modeling of Hydrophobic Organic Contaminants Uptake and Sequestration by Soil Organic Matter

EPA Grant Number: R825540C002
Subproject: this is subproject number 002 , established and managed by the Center Director under grant R825540
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Duke University Center for Environmental Implications of NanoTechnology
Center Director: Wiesner, Mark R.
Title: Molecular Modeling of Hydrophobic Organic Contaminants Uptake and Sequestration by Soil Organic Matter
Investigators: Johnson, James H. , Diallo, Mamadou S.
Institution: Howard University
EPA Project Officer: Hahn, Intaek
Project Period:    
Project Period Covered by this Report: January 1, 1998 through September 30, 1999
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text |  Recipients Lists
Research Category: Hazardous Substance Research Centers , Land and Waste Management

Objective:

The primary objective of this research is to develop a molecular level understanding of the uptake of hydrophobic organic compounds (e.g., phenanthrene and PCE) by two "soft" and "hard" model SOM: Chelsea humic acid (CHA) and Lachine kerogen (LK). The ultimate objective of this research, which involves a close collaboration with Dr. Weilin Huang (Drexel University), Dr. Walter Weber (University of Michigan) and Dr. William Goddard III (Caltech), is to develop and validate molecularly based quantitative tools for predicting HOC uptake and sequestration by SOM.

Progress Summary:

Rationale: The uptake and sequestration of hydrophobic organic compounds (HOCs) by soil organic matter (SOM) determine to a large extent their fate and transport in subsurface systems. Thus, a molecular level understanding of the uptake and sequestration of HOCs by SOM is critically needed to improve our ability to (i) predict their environmental fate, (ii) conduct more rigorous assessments of their toxicity and (ii) set more "risk" based cleanup standards for contaminated soils and sediments.

Approach: The proposed research has been structured around three tasks: I. Experimental Characterization, II. Computer Assisted Structure Elucidation and Molecular Modeling and III Atomistic Simulations of Contaminant Uptake and Sequestration. During the first year of this project, we have focused on Tasks I and II.

Client/Users -Technology Transfer and Outreach Plan: Although additional NMR and MS experiments are being carried out at EMSL and Howard University to provide better input data for the modeling efforts of Task II, we have begun taking the necessary steps to introduce our novel humic modeling approach to the environmental science and engineering community. We have recently submitted an abstract to the organizers of an ACS Division of Environmental Chemistry Symposium on Computational Methods in Environmental Chemistry. This symposium will be held during the ACS spring meeting in San Francisco (March, 2000). We also have an ongoing collaboration with two DOE national laboratories (PNNL and Sandia) one the characterization and modeling of CHA. Finally, we have recently secured a 3 year supercomputer grant from the DOE/PNNL-EMSL project Grand Challenges in Molecular Environmental Sciences (in collaboration with Prof. Richard Friesner of Columbia University and Prof. William A. Goddard III of Caltech) to carry out large scale molecular dynamics simulations of HOC uptake and sequestration by CHA matrices.

We are also collaborating with the National Institute of Standards and Technology Center for Neutron Research, a major research center used by US industry and universities to characterize various types . This collaboration is currently structured around two projects: (i) characterization of humic/fulvic acid by neutron powder diffraction and (ii) small angle neutron scattering investigations of humic/fulvic acid aggregates in aqueous solutions.

We will also work with the Technology Transfer Offices of the Great Lakes and Mid-Atlantic Hazardous Substance Research Center to help disseminate our findings to environmental scientists and engineers.We will also take all the necessary steps to present our results during upcoming national/professional meetings of environmental scientists/engineers. We will also submit manuscripts for publication in peer reviewed journals such as ES&T.

Journal Articles:

No journal articles submitted with this report: View all 2 publications for this subproject

Supplemental Keywords:

RFA, Scientific Discipline, TREATMENT/CONTROL, INTERNATIONAL COOPERATION, Waste, Water, Hazardous, Chemical Engineering, Environmental Chemistry, Contaminated Sediments, Hazardous Waste, Treatment Technologies, Bioremediation, Ecology and Ecosystems, Environmental Engineering, alternative endpoints, bioavailability, hazardous organic compounds, contaminant transport, bioremediation of soils, kinetic studies, contaminated sediment, in-situ bioremediation, fate and transport , contaminated groundwater, groundwater remediation, contaminated soil, bioaccumulation, environmentally acceptable endpoints, groundwater, biodegradation, in situ remediation, bioacummulation, contaminants in soil, contaminated soils, molecular modeling

Progress and Final Reports:

Original Abstract

2000 Progress Report

Final

Main Center Abstract and Reports:

R825540    Duke University Center for Environmental Implications of NanoTechnology

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825540C001 Development and Verification of A Molecular Modeling Approach for Predicting the Sequestration and Bioavailability/Biotoxicity Reduction of Organic Contaminants by Soils and Sediments
R825540C002 Molecular Modeling of Hydrophobic Organic Contaminants Uptake and Sequestration by Soil Organic Matter
R825540C003 The Use of Microfiltration and Ultrafiltration Membranes for the Separation, Recovery, and Reuse of Surfactant/Contaminant Solutions
R825540C004 A Contained Simulation of Field Application of Genetically Engineered Microorganisms (Gems) for the Bioremediation of PCB Contaminated Soils