Fundamental and Applied Chemistry Relevant to the Use of Humic Acids

EPA Grant Number: R828158
Title: Fundamental and Applied Chemistry Relevant to the Use of Humic Acids
Investigators: Von Wandruszka, Ray
Institution: University of Idaho
EPA Project Officer: Lasat, Mitch
Project Period: July 1, 2000 through June 30, 2002
Project Amount: $188,697
RFA: Exploratory Research - Engineering, Chemistry, and Physics) (1999) RFA Text |  Recipients Lists
Research Category: Water , Land and Waste Management , Air , Engineering and Environmental Chemistry

Description:

The use of bulk humic acids (HAs) in pollution remediation will be studied from both fundamental and applied perspectives. The focus will be on the detergent qualities of these substances in aqueous solution, and the roles played by concentration, temperature, ionic strength, and types of metal ions present. The work will involve monitoring the micelle-like aggregates formed by aqueous HAs, which give them the ability to solubilize and isolate pollutants such as petroleum products. The use of HAs for the removal metallic contaminants from waste water will also be investigated, especially through a continuous elution process involving columns packed with granular HA. Both traditionally extracted and unrefined HAs will be considered. The factors influencing HA detergency will be determined, and HA extraction procedures for acidic mine run-off will be developed.

Approach:

Dynamic light scattering (DLS) measurements will be used to follow the evolution of HA aggregates in response to changes in the solution parameters. The findings will be related to those obtained from earlier fluorescence studies. Preparative size exclusion chromatography will be employed to isolate HA fractions, so that the influence of molecular weight on aggregation can be evaluated. Further studies of the kinetics of HA - metal interactions will be conducted by both fluorimetry and DLS. The sequestration of hydrophobic species by dissolved HA will be monitored by a pyrene immobilization technique developed in our laboratory. In all instances, a selection of HA and metal ions will be used to determine the effects of humic molecular features and cation charge and size on the surface activity enhancements resulting from their interactions. The application of unrefined bulk HAs to the decontamination of water will be evaluated by a column extraction techniques. Metallic contaminants (incl. mercury, lead, and cadmium) in acidic mine run-off streams will be considered, as well as petroleum products and chlorinated solvents.

Expected Results:

The proposed studies will show how, and on what time scale, the detergent characteristics of dissolved HAs are modified by different metal ions, and how this influences their ability to interact with small hydrophobic molecules. Techniques will be developed to use HA extractants for the removal of metallic and organic contaminants from waste waters. If the expected results are achieved, innovative remediation technology will become available for the treatment of polluted soil and water, including highly acidic mine wastes.

Publications and Presentations:

Publications have been submitted on this project: View all 8 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 3 journal articles for this project

Supplemental Keywords:

chemicals, PAH, PCB, bioavailability, organics, remediation, cleanup, restoration, limnology, monitoring, analytical, Idaho (ID), Montana (MT), agriculture., RFA, Scientific Discipline, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Bioavailability, mercury transport, Remediation, Environmental Chemistry, Chemistry, Restoration, State, Ecology and Ecosystems, Aquatic Ecosystem Restoration, Engineering, Chemistry, & Physics, Mercury, contaminated mines, humic substances, dynamic light scattering, contaminant transport, Idaho (ID), acid mine drainage, lead, PCBs, metal release, restoration strategies, polychlorinated biphenyls, analytical chemistry, humic acid, alternative cleanup standards, aquatic ecosystems, acid mine discharge, humic acids, control technologies, Montana , restoration planning, mercury concentration

Progress and Final Reports:

  • 2001 Progress Report
  • Final Report