Document Detail

Influence of organic acids on the transport of heavy metals in soil.
MedLine Citation:
PMID:  18482743     Owner:  NLM     Status:  MEDLINE    
Vegetation historically has been an important part of reclamation of sites contaminated with metals, whether the objective was to stabilize the metals or remove them through phytoremediation. Understanding the impact of organic acids typically found in the rhizosphere would contribute to our knowledge of the impact of plants in contaminated environments. Heavy metal transport in soils in the presence of simple organic acids was assessed in two laboratory studies. In the first study, thin layer chromatography (TLC) was used to investigate Zn, Cd, and Pb movement in a sandy loam soil as affected by soluble organic acids in the rhizosphere. Many of these organic acids enhanced heavy metal movement. For organic acid concentrations of 10mM, citric acid had the highest R(f) values (frontal distance moved by metal divided by frontal distance moved by the solution) for Zn, followed by malic, tartaric, fumaric, and glutaric acids. Citric acid also has the highest R(f) value for Cd movement followed by fumaric acid. Citric acid and tartaric acid enhanced Pb transport to the greatest degree. For most organic acids studied, R(f) values followed the trend Zn>Cd>Pb. Citric acid (10mM) increased R(f) values of Zn and Cd by approximately three times relative to water. In the second study, small soil columns were used to test the impact of simple organic acids on Zn, Cd, and Pb leaching in soils. Citric acid greatly enhanced Zn and Cd movement in soils but had little influence on Pb movement. The Zn and Cd in the effluents from columns treated with 10mM citric acid attained influent metal concentrations by the end of the experiment, but effluent metal concentrations were much less than influent concentrations for citrate <10mM. Exchangeable Zn in the soil columns was about 40% of total Zn, and approximately 80% total Cd was in exchangeable form. Nearly all of the Pb retained by the soil columns was exchangeable.
A P Schwab; D S Zhu; M K Banks
Related Documents :
22073263 - Molecular evolution of hiv-1 crf01_ae env in thai patients.
12234803 - Reverse flux through cardiac nadp(+)-isocitrate dehydrogenase under normoxia and ischemia.
16633593 - Photodegradation of toluene over tio(2-x)n(x) under visible light irradiation.
Publication Detail:
Type:  Journal Article     Date:  2008-05-15
Journal Detail:
Title:  Chemosphere     Volume:  72     ISSN:  0045-6535     ISO Abbreviation:  Chemosphere     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-06-09     Completed Date:  2008-08-28     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0320657     Medline TA:  Chemosphere     Country:  England    
Other Details:
Languages:  eng     Pagination:  986-94     Citation Subset:  IM    
Department of Agronomy, Purdue University, West Lafayette, IN 47907, United States.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Biodegradation, Environmental
Carboxylic Acids / analysis*,  chemistry
Chromatography, Thin Layer
Metals, Heavy / analysis*
Models, Theoretical
Rhizome / growth & development
Soil* / analysis,  standards
Soil Pollutants / analysis*
Reg. No./Substance:
0/Carboxylic Acids; 0/Metals, Heavy; 0/Soil; 0/Soil Pollutants

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Heterogeneity in the A33 protein impacts the cross-protective efficacy of a candidate smallpox DNA v...
Next Document:  Intestinal T-cell and natural killer-cell lymphomas in Taiwan with special emphasis on 2 distinct ce...