CONICET | Buscador de Institutos y Recursos Humanos

Soil contamination by organic compounds is of great concern worldwide since it could act as a major environmental repository. The extent of phytoremediation success is conditioned by two main factors: the availability and toxicity of the compound to be remediated, and the plant species. This study aimed to assess the potential of different plants species for remediation of aged DDTs residues in soil. Tomato, sunflower, soybean and alfalfa plants were grown in contaminated soils (p,p?-DDE 455.3, p,p?-DDT 63.5 ng/g dry weight) for 15 and 60 days. Phytoremediation was evaluated by studying the pollutant dynamics in the soil-plant system and lipid peroxidation (LPO) as a tolerance biochemical indicator. Results showed that soil DDTs levels were diminished after 60 days of plant growth, indicating the continuous DDTs uptake by roots. The relative accumulation of each compound was dependent on soil levels (p,p?-DDE> p,p?-DDT> p,p?-DDD) and all species presented root > aerial accumulation pattern, evidencing DDTs translocation. Tomato plants were the most effective in the enhancement of pollutants bioavailability in the rizospheric soil. Plants growth induced physicochemical changes in soil by increasing dehydrogenase activity and DDTs metabolism, mainly in soybean and tomato soil fractions. Root bioconcentration factors > 1 were observed for 15 days in tomato and alfalfa plants with a root growth dilution effect at 60 days in all species, except soybean. DDTs uptake did not affect tomato and alfalfa plants growth neither caused oxidative stress (LPO). Considering the accumulation potential, tolerance (expressed as no evident phytotoxicity effects) and interaction with soil matrix in terms of metabolism and availability, tomato plants seems to be the best phytoremediation candidates for aged soil DDTs residues.