Phytorestoration Potential of Hydrocarbon-Induced Physicochemical Changes in Parts of Nigeria Eastern Niger Delta Waste oil Polluted Soil

Abstract

Many fundamental questions concerning the indiscriminate disposal of automobile effluent as a major non-point source of oil pollution, it induced impact and changes in soil physiochemical properties the application of phytotechnology remain unanswered in parts of eastern Niger Delta. This study was aimed at evaluating the phytoremediation potency of Peltophorum pterocarpum, Leucaena leucocephala, and Crotolaria retusa (Fabaceae family) with the objectives of quantifying the changes in the physicochemical properties of the soil under polluted and phytoremediated condition. The methodology adopted involved universally accepted ecological field and laboratory standards. Result revealed increased anionic content of nitrate (9.98±1.84mg/g) and phosphate (0.32±0.07mg/g), decreased chloride (0.01±0.00mg/g) and sulphate (1.82±0.30mg/g) in polluted condition, but increased across remediated soils with Peltophorum soil highest in content. Cations decreased under pollution, increased in remediated soils with magnesium (69.26±0.08mg/g) and potassium (17.40±7.05mg/g) higher in Crotolaria, calcium (187.87±0.45mg/g) in Peltophorum and sodium (6.38±1.01mg/g) in Leucaeana soils. Decreased pH (5.46±0.17), moisture (18.70±2.05%), clay (11.53±0.74%), silt (7.20±2.01%), particle density (2.49±0.05g/cm) and porosity (51.34%) decrease across pollution were recorded but increased among species treated soils with Peltophorum soil higher in restoration. The increased sand particle (81.60±2.43%), organic matter (3.15±0.43%), bulk density (1.21±0.09g/cm), oil & grease (1.52±0.32mg/g), Total hydrocarbon (3.97±0.26mg/g) and electrical conductivity (24.30±2.62µS/cm) in pollution, decreased in Peltophorum soil among species treatment with significant difference (P<0.05). The species in view of their variant tolerance to hydrocarbon and potency can thus be suggested as an integral part of remediation measure to soil environmental decontamination.