Persulfate treatments of phenanthrene-contaminated soil: Effect of the application parameters

PELUFFO, MARINA; MORA, VERÓNICA C.; MORELLI, IRMA S.; ROSSO, JANINA A.

GEODERMA

ELSEVIER SCIENCE BV

Año: 2018 vol. 317 p. 8 - 14

0016-7061

The aim of this work was to study the effects of the parameters involved in persulfate (PS) application, namely,the cation counterion, mode of persulfate addition and soil-moisture content, to optimize the use of low doses ofPS coupled with bioremediation technologies. Soil microcosms were contaminated with 110 ± 20 mg of phenanthreneper kilogram of dry soil. The efficiency of each treatment in phenanthrene elimination was evaluated.Additionally, the impact on cultivable autochthonous heterotrophic bacteria populations was examined.The addition of sodium persulfate in successive doses (14.9 g/kgDS) showed the greatest efficiency in phenanthreneelimination (36%) after 7 days of treatment, but inhibited further bioremediation. Sodium persulfatewas more efficient than ammonium. Increased moisture enhanced the bioremediation but inhibited the oxidativetreatment. The persulfate-ion decomposition rate decreased at high moisture levels, possibly through dilutingactivators within the soil.The results suggest that, for oxidative treatments of contaminated soil, the application of low doses of sodiumPS at low soil-moisture levels is the most effective option for an elimination of phenanthrene that is compatiblewith bioremediation.