THE EFFECTS OF TRITICUM AESTIVUM SPECIES FOR THE PHYTOREMEDIATION OF PETROLEUM-CONTAMINATED SOIL

The study on the phytoremediation of sites polluted with total petroleum hydrocarbons (TPH), using the species Triticum aestivum, was made in order to identify the optimal strategy for the rehabilitation of some lands destroyed by industrial activity. The study highlights the necessity of using organic fertilizers in the absence/presence of zeolitic rock from Marsid (Romania), which contains 72% clinoptilolite (indigenous volcanic tuff). The study was made in a greenhouse, in pots containing 1.5 kg dry soil, in the following variants: polluted soil, soil treated with indigenous volcanic tuff, 5% wt./wt.; soil treated with stabilized municipal sludge, 50t.ha(-1); soil treated with stabilized municipal sludge combined with indigenous tuff, vs. the control variant, unpolluted soil. Each experimental variant was made in three replications. The treatment with organic fertilizers based on anaerobically stabilized municipal sludge, in the absence/presence of volcanic tuff, determined high degree of germination, similar to the one in the control variant. The wheat plants installed on the variants of treated polluted soil tolerate the presence of a TPH quantity of 0.819 +/- 0.016g/kg D.M. The complex fertilization treatment for polluted soils determined additional intake of nutrients through the bio waste used. Under these conditions, the radicular system of plants presents roots which are well-developed, branched, and able to metabolize the TPH in polluted soils. Moreover, the addition of volcanic tuff determined more efficient growing of the aerial part of plants than in the plants obtained in the other experimental variants. Reduction of TPH in the soils treated with fertilizers in the absence/presence of volcanic tuff was 20.4 - 25.81% in the presence of wheat plants.