Biodegradation of phenanthrene in soils in the presence of surfactants

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:7079156

Jahan, K

This research addresses the effect of low surfactant concentrations on the biodegradation of slightly soluble organic compounds in the presence and absence of soil. Biodegradation of phenanthrene in excess of its aqueous solubility by an acclimated mixed culture was studied in the presence of nonionic surfactants. Nonionic surfactants were selected over other types of surfactants because of their higher hydrocarbon solubilizing power, weaker adsorption to charged sites, less toxicity to bacteria, and poor foaming properties. Surfactants were tested to measure their effectiveness for increasing the solubility of phenanthrene, their adsorption on the soil matrix, their biodegradability, their effect on the adsorption of phenanthrene and on the rates of biodegradation of phenanthrene. Solubility enhancement studies of phenanthrene by the surfactants indicated relatively small effects at sub-micellar surfactant concentrations. Batch biodegradation studies in which phenanthrene was available as particulates and as a surface coating on sand were carried out in closed BOD bottles in the Hach manometric system. Addition of surfactants at 25 mg/L enhanced biodegradation rates as measured by oxygen uptake, protein production and disappearance of phenanthrene. A dynamic model which couples dissolution and biodegradation processes could adequately represent the experimental batch data. Modelling studies suggest that biodegradation was accelerated because the dissolution rates of phenanthrene increased in presence of the surfactants. Continuous flow column studies with phenanthrene coated Jordan sand was carried out to simulate groundwater flow conditions. Sorption studies on Jordan aquifer sand indicated that this low-carbon aquifer material adsorbs small amounts of phenanthrene as well as surfactants. The tests show that low surfactant concentrations were marginally beneficial in washing phenanthrene from precoated sand.

• Research Organization: Minnesota Univ., Minneapolis, MN (United States)
• OSTI ID: 7079156
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
AROMATICS
BACTERIA
BIODEGRADATION
BIOLOGICAL PATHWAYS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
CONDENSED AROMATICS
DECOMPOSITION
DISSOLUTION
EVALUATION
HYDROCARBONS
MATHEMATICAL MODELS
MICROORGANISMS
ORGANIC COMPOUNDS
PHENANTHRENE
REMEDIAL ACTION
SOILS
SORPTIVE PROPERTIES
STIMULATION
SURFACE PROPERTIES
SURFACTANTS