Phytoremediation of sewage sludge in soils contaminated with heavy metals

The main source of heavy metals in most soils is sewage sludge. Naturally, the heavy metals in soils are transported to vegetations and cultivated crops. These pollutants need to be either reduced or eliminated in the soil to remediate the effects to man, animals, plants, soils, and groundwater. Hence, Jatropha curcas seedlings were planted on six different media to determine the concentration of heavy metals. Thereafter, it was discovered that Jatropha curcas plants through their roots, stems and leaves metabolism, morphology and mechanisms can reduce the concentration of heavy metals like Zinc, Lead, Chromium, Cadmium, and Copper etc effectively from any medium containing 100% sewage sludge. Thus, it was discovered that Jatropha curcas plant is suitable as a phytoremediator of heavy metals in soils. KEYWORDS: Heavy metal, phytoremediation, sewage sludge, metabolism, morphology

PALEOEVIRONMENT OF NIGERIA'S AJALI SANDSTONES: A PEBBLE MORPHOMETIC APPROACH.

The Ajali Sandstone is a major clastic formation of Campanian-Maastrichtian age occuring within the Anambra Basin, Southeastern Nigeria. The Sandstones have a high incidence of quartz and feldspar pebbles. Clasts of vein quartz pebbles were selected for morphometric study of decipher the depositional environment of the sandstone. The three mutually perpendicular axes of each pebble were measured and the roundness estimate with the aid of a roundness image set. Morphometric parameters such as size, flatness ratio, elongation ratio, elongation ratio, maximum projection sphericity, form geometry and oblate index were computed. Bivarite scattergrams of roundness versus oblate-prolate index were plotted. Except for the flatness ratio which is non-diagnostic, all the other results of the morphometric studies indicated a fluvial – dominated depositional environment. The result is in line with earlier conclusions of fluvial or fluviodeltaic depositional environment. The result is in line with earlier conclusions of fluvial or fluviodeltaic depositional environment based on analysis of faceis, sedimentary rock which are suitable for morphometrical research: those with isotropic constitution and high resistivity to wear such as cherts, quartz sandstones and some related types. KEY WORDS: Clastic formation, Fluviatile, Fluviodeltaic, Elongation ratio, Oblate index. Global Jnl Geological Sciences. Vol.2(1) 2004: 37-4