Enrichment cultures of microorganisms separated from soil contaminated with pentachlorophenol and creosote were able to grow on and degrade phenol (300 mg 2-chlorophenol (100 mg L⁻¹), or 4-chlorophenol (100 mg L⁻¹) when added as the sole carbon source, but were unable to degrade 3-chlorophenol (100 mg L⁻¹) even after more than 127 days of incubation. Phenol biodegradation by enrichment cultures was completely inhibited by temperatures at or above 37 °C or phenol concentrations greater than 1,200 mg L⁻¹. Phenol degradation rates were reduced in the absence of an inorganic nitrogen source. Two species of gram-negative bacterial isolates from this soil degraded 300 mg L⁻¹ phenol in three to twelve days. A yeast isolate degraded 300 mg L⁻¹ phenol more quickly, in one to three days. No isolates were found that degraded any of the chlorinated compounds. Phenol biodegradation by the yeast was completely inhibited by substrate concentrations greater than 1,000 mg L⁻¹; it was partly inhibited by low dissolved-oxygen concentrations, substrate concentrations greater than 500 mg L⁻¹, and the presence of alternative carbon sources such as acetate or glucose. Acetate also inhibited yeast growth in the presence of phenol, while glucose stimulated it. The addition of yeast extract or thiamin stimulated yeast growth and phenol degradation by the yeast. In enrichment cultures, growth factors were provided to yeast by other microorganisms. Maximum rates of phenol degradation by yeast and enrichment cultures were comparable, often greater than 300 mg L⁻¹ phenol per day. Doubling times for yeast growing on phenol were generally from three to five hours. The rapid rates of growth and phenol degradation by isolates and enrichments suggest that biodegradation of phenol in the subsurface should not be substrate limited. Rather the transport of dissolved oxygen by advection/dispersion or vertical diffusion should limit phenol degradation by aerobic metabolic pathways in groundwater.

A linear distribution isotherm described the sorption/desorption of four phenols on the Pima clay loam soil. The linear distribution coefficients for 2,4-dichlorophenol, 2-chlorophenol, phenol and 2,4,6-trichlorophenol were 3.61, 2.93, 0.87, and 0.79. Ionization of the phenols affected their relative distribution order. Hydrogen bonding of phenols to exposed mineral sites accounted for the greater measured sorption than was predicted. The effect of solid concentration on the distribution of phenols was tested over a 10-fold soil/solution range. When a log transformation was performed on the data, a highly significant inverse relationship existed between the distribution of phenols and the soil/solution ratio. A 3-fold increase in the dissolved organic carbon in solution was associated with the decrease in the distribution coefficient. A 3-fold increase in the fraction organic carbon in the soil occurred when dry sludge solids were added to the Pima soil. A substantial increase in the dissolved organic carbon in solution was associated with the addition of sludge solids to the soil. (Abstract shortened with permission of author.)

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The concentration of phenols in the soils environment and their fate was studied as a function of five different soil types, six different monohydroxyphenols, and three different municipal landfill leachates media. Concentrations of naturally occurring phenols were also followed for a period of one year in young and old leachates. Methods for analysis of phenols were reviewed for quantitative and qualitative analysis of phenols in landfill leachates. To determine the adsorptive capabilities of the soils used in this study, the isotherm approach was used after the equilibration time of phenols in soils was determined to be five days. Concentrations of phenols varying from 5 ppm to 100 ppm were used to construct isotherm graphs. The soil-phenol isotherm curves conformed very well to the Freundlich equation, indicating multiple adsorption mechanisms and slow equilibration times in the soilsphenols reactions. A statistical analysis of the isotherm data showed %-free iron oxides to be the most important soil characteristic for the adsorption of phenols by all soils; followed by soil pH and % clay in order of significance. High solubility and moderate polarity of phenols also were found to be favorable factors in the adsorption of phenols by soils. Naturally occurring phenols such as cresols disappeared fastèr from soil solutions than synthetic phenols. The reactivities of phenols with MSW leachates increased with the age of the leachates. Very young leachates, having low pH and high TOC levels favored synthetic phenols over naturally occurring phenols to react with. All leachates studied demonstrated an ability to remove from solution one or more of the six phenols used in large quantities over a period of 15 days or less. The overall performance of the leachates used in this study seemed to be a function of the humic acid levels found in them. Levels of naturally occurring phenols in leachates varied from several ppbs to more than 9000 ppbs for a year's period. The highest phenol levels were found in the young phenols and the lowest levels in the old phenols; indicating that pH and TOC concentration determine the amounts of phenols in solution. In column studies of perfusion of leachates through 10 cm of soil materials packed at field densities, no soil was able to stop the migration of phenols for more than 5 to 10 pore volume displacements. Low pH and high TOC levels seemed to play a much larger role in the migration of phenols through soils than the levels of phenols found in the leachates used. The use of phenol enriched deionized water passed through soil columns showed the fact that there is a clear dependency of adsorption of phenol on the flow rate. Slow rates favored adsorption of phenol by all soils studied. The TOC analysis of the effluents from the phenol enriched water-soil columns studies indicated that some mechanisms for the disappearance of phenol from soil solution may have been transformation reactions as well as adsorption reactions. Varying TOC levels with flux seemed to indicate that these reactions are much slower than the adsorption reactions. The use of Cu⁺² saturated soils in an attempt to correlate transformation reactions of phenol with transition metal catalytic properties failed to increase the adsorption and/or transformation of phenol in the soil media. The 4-aminoantipyrine colorimetric method performed well in the analysis of phenols in air unstable leachates. Gas-liquid chromatography using NPGSB+H₃PO₄ on Anakrom A 90/100 mesh was used for the quantitative and qualitative analysis of phenols in leachates.