Phosphorus Dynamics of Soils and Subsoils Treated By Thermal Desorption.

Low temperature (200 to 500 °C) thermal desorption (TD) is an effective method for removing hydrocarbons from soils. In some instances, the goal for these remediated soils may be agricultural production. Thus, understanding the effects of TD on nutrient dynamics is crucial from agronomic and environmental perspectives. This study examined the effects of TD (heated to 350 °C for 8-10 min) on P sorption-desorption characteristics in 1) native, non-contaminated topsoil; 2) native, non-contaminated subsoil material; and 3) crude-oil contaminated subsoil material. A batch experiment was used and soils were equilibrated with 0, 5, 10, 20, 50, 75 and 100 mg P L^-1. Total nitrogen (TN), non-purgeable OC and dissolved solution P were measured. The sorption of P by the soil materials was analyzed by fitting the sorbed concentrations of P using Freundlich and Langmuir isotherms. Phosphorus dynamics in reclaimed, oil-contaminated soils is especially critical when these soils will be used for cereal or row-crop production.

Low temperature (200 to 500 °C) thermal desorption (TD) is an effective method for removing hydrocarbons from soils. In some instances, the goal for these remediated soils may be agricultural production. Thus, understanding the effects of TD on nutrient dynamics is crucial from agronomic and environmental perspectives. This study examined the effects of TD (heated to 350 °C for 8-10 min) on P sorption-desorption characteristics in 1) native, non-contaminated topsoil; 2) native, non-contaminated subsoil material; and 3) crude-oil contaminated subsoil material. A batch experiment was used and soils were equilibrated with 0, 5, 10, 20, 50, 75 and 100 mg P L^-1. Total nitrogen (TN), non-purgeable OC and dissolved solution P were measured. The sorption of P by the soil materials was analyzed by fitting the sorbed concentrations of P using Freundlich and Langmuir isotherms. Phosphorus dynamics in reclaimed, oil-contaminated soils is especially critical when these soils will be used for cereal or row-crop production.