Factors affecting binding of chlorophenols to soil

Synthetic substituted phenols can become incorporated into soil organic matter by processes similar to natural humification. Biological, (enzyme-catalyzed), and abiotic, (mineral surface catalyzed), reactions have been implicated in these processes which result in the nonextractable binding of phenolic contaminants to soil organic matter. Experiments conducted with phenol, 4-monochlorophenol (MCP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP) indicated a statistically significant difference in the degree of nonextractable binding in oxic and anoxic environments. Soils were extracted with water and methylene chloride. The extracted soils were combusted at 950°C and the 14C02 evolved was quantified as a measure of the bound contaminant. The amount of 14C02 captured during combustion of the soils indicated that approximately two times greater contaminant binding occurred in the oxic atmosphere as compared to the anoxic atmosphere. Autoclaving the soil resulted in a reduction in contaminant binding. Addition of H₂O₂ increased MCP binding by 4.5 times. The nonextractable contaminant appeared to consist of (i) a biologically coupled; (ii) an abiotically coupled; and (iii) a desorbable, but diffusion-limited component. The initial aqueous concentration of the contaminant appeared to have the greatest effect on the degree of nonextractable binding. An empirical model was developed for predicting the extent of chlorophenol binding to soil as a function of the initial aqueous concentration of the contaminant. Nearly 50% of the nonextractable 4-MCP was bioavailable to inoculated microorganisms.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Civil Engineering

Department dc:contributor.department

Civil Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1995

Author dc:creator

• Bhandari, Alok

Chair dc:contributor.committeechair

• Novak, John T.

Committee members dc:contributor.committeemember

• Berry, Duane F.
• Dietrich, Andrea M.
• Benoit, Robert E.
• Randall, Clifford W.

• oxidative coupling
• bioavailability
• soils

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-09192008-063010

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/39390