This paper reports results of 2,3,7,8-tetrachlorodibenzo p-dioxin (TCDD) destruction on artificially contaminated soil using cobalt-60 (60Co) γ radiation. Important parameters (soil moisture content, surfactant type/concentration, equilibration, and radiation dose) and their optimum ranges are identified. Scavenger (N2O, O2, 2-propanol) studies were conducted to explore the consequences of controlling oxidative and reductive conditions in the soil, and reaction byproducts have been analyzed under selected reaction conditions. A standard soil (EP A SSM-91) was artificially contaminated with 2,3,7,8-TCDD to 100 ppb, and in the presence of 25 % water and 2 % surfactant (RA-40) and at a high irradiation dose (800 kGy), greater than 92% TCDD destruction was achieved, resulting in a final TCDD concentration of less than 7 ppb. Results of scavenger and byproduct studies and theoretical target theory calculations indicate that TCDD destruction is caused primarily by direct radiation effects and proceeds through reductive dechlorination.
ASJC Scopus subject areas
- Environmental Chemistry