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2 International Letters of Chemistry, Physics and Astronomy

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Quantitative Changes in Soil Properties and Plant Uptake of Metals on Municipal Solid Waste Dumpsite in Nigeria

Ogunmodede O. T., Adewole E., Ojo A. A.

International Letters of Chemistry, Physics and Astronomy

2015

Vol. 52

152--162

In this work concentrations of Cd, Pb, Cr, Fe, Co, Ni, Cu, Zn and Mn were determined in soils and plants from refuse dumpsites in Ado Ekiti, Nigeria. The refuse dump soils were evaluation using contamination/pollution factor (C/P), Enrichment factor (EF), Index of Geoaccumulation (Igeo) and Pollution load index were calculated. The observation suggests high C/P values of the dump soil are polluted by Cd, Cr and Ni acts as a sink for heavy metals contributed from anthropogenic sources in the study area. C/P data, EF, PLI and (Igeo) indicated that these heavy metals originate from anthropogenic sources. Fe and Ni loads in plants from the refuse dump soils pronounced maximum concentration than Nigeria guideline. Transfer ratios for Cd, Co, Cu, Zn, Pb and Fe of plants from the control soils were higher than those from the refuse dump soils.

Enhancing adsorption capacity of clay and application in dye removal from waste water

Ogunmodede O. T., Adebayo O. L, Ojo A. A.

International Letters of Chemistry, Physics and Astronomy

2014

Vol. 20, iss. 1

35--51

Natural clay has been considered as a potential absorbent for removing pollutants from water and waste water. Nonetheless, the effective application of clay for water treatment is limited due to small surface area and presence of net negative surface charge, leading to it low adsorption capacity. The absorption capacity was boosted via intercalation of CaO derived from snail shell (SS). The methylene blue sorption potential, PZC, and the surface area of unmodified clay sample were substantially enhanced by the intercalation process. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The value of the Langmuir monolayer sorption capacity qm (mg/g) increased from 50.12 to 88.71, PZC values increased from 4.50 to 7.40, and the surface area (m2/g) value increased from 27 m2/g to 123 m2/g after the intercalation process. The experimental data were fitted into two kinetic models: Lagergren pseudo-first order and the chemisorptions pseudo-second order. It was observed that chemisorptions pseudo-second order kinetic model described the sorption process with high coefficients of determination (r2) better than pseudo first other kinetic models. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework.