Lolium Perenne - a phytoremediation option in case of total petroleum hydrocarbons polluted soils

Abstract

Rehabilitation of polluted soils with petroleum products requires a re-vegetation strategy to obtain a green mass cover that can quickly and efficiently cover the polluted soil. For the gradual recovery of the destroyed soil, it was necessary: 1. adequate soil treatments with fertilizer i.e. sewage sludge and fly ash as amendment, 2. plant species selection, 3. agronomical works in accordance with geographical position and climatic conditions. Fertilizers and fly ash create conditions for plant installation, by nutrients insurance. Our experiment was conducted in pots with 91.73±11.12 [gKg-1 D.M (dry matter)] total petroleum hydrocarbons (TPH) polluted soil, fertilised with sewage sludge and fly ash 60 [tha-1] derived from the burning of fossil fuels in thermal power plants. The selected plant species for bio-remediation is Lolium perenne. The selected plant species Lolium perenne is installed on 50-90% of the land surface giving 8 successive crops of grass in the warm season. The TPH reductions of polluted and treated soil were 38.4-56.3 [%]. The biomass did not bioaccumulate chromium at the detection limit. The amounts of cadmium, lead and zink bioaccumulated in the aerial parts were below acceptable limits. The obtained biomass can be used as animal feed or for bedding in shelters. The soil remediation efficiencies of 91.73 ± 11.12 [gKg-1 D.M] were directly proportional to the amount of fly ash used.