Potentially Exploitable Base-Metal Containing Bentonite Clay Minerals of Ibeshi-Ikorodu South-Western Nigeria for Oil Bleaching

The experiment has been undertaken to evaluate the bleaching capacity of Ibeshi Montmorillonite-Bentonite clay to be used on soya bean oils (edible oils). The clay capacity for bleaching was evaluated before and after acid activation processes. The acid-activated Bentonite was prepared from raw Bentonite with sulphuric acid of concentrations 6 M, 7 M, and 8 M; this is because availability of hydrogen is a competitor at ions exchange site. Acid activation promotes catalytic activities by increasing the number of active sites of the clay samples. The results from AAS, GC-MS analysis and the spectra of the raw clay indicated that the dominant components present were Al2O3, MgO, CaO, Na2O, and K2O together with Fe2O3, TiO2, MnO2 and P2O5. The ratio of Na2O:CaO is 0.24-0.30, a value less than one, indicative the presence of montmorillonite, and the SiO2 : Al2O3 between ratio of 1.12-1.50 greater than one. The optimum acid concentration for industrial bleaching is 6 M H2SO4. However, the exchange capacity was observed at pH 7. The work has shown that activated montmorillonite/Bentonite clay has other useful organic compounds such as organic complexes 2, 4-Nonadienal; up to 8% α-Tocopherol. Tests for bleaching performance evaluation confirmed that the clay has moderately bleaching action as shown by percentage colour reduction. The colour reduction for natural clay was 9.1%, this value increases to 27.3% after 8M H2SO4 activation. Other properties include the structural characteristics, free fatty acid value, viscosity were also recorded. The availability of Bentonite across Nigeria makes it a potential industrial mineral for the economy development.Keyword: Bentonite, clay, dominant, components, acid-activate

Apatite group minerals : solubility and environmental remediation

Soils, wastes and waters contaminated by hazardous geochemical trace elements represent actual or potential threats to living organisms. Depending on the degree of environmental threat or the level of risk, contaminated systems may be subjected to remediation with the primary aim of reduction of the threat to an acceptable level. In this connection it is noted that the acceptable maximum contaminant level of a chemical element or substance is defined on a country-by-country basis, and may involve national or international standards. Several remediation techniques are available to remove, reduce or immobilize hazardous elements in wastes, soils and waters. Remediation processes based on chemical treatments aim to destroy contaminants or convert them into less environmentally hazardous forms [1]. Environmental problems that result from the contaminant’s high solubility can sometimes be solved by in situ immobilization by addition of appropriate reactants. Here, attention is drawn to the apatite group of minerals, and especially to the arsenate and phosphate members that contain calcium and lead. These have recognised applications, and limitations, in stabilization processes used for soils, wastes and waters contaminated by certain hazardous geochemical trace elements