The amount of plastic waste generated in developing nations like Nigeria is increasing day by day, which is nonbiodegradable and causes environmental pollution. Among the plastics used, low-density polyethylene is abundant. These plastics can be removed from the environment and recycled into useful products. In this study, low-density polyethylene plastic waste was utilized in the manufacture of floor tiles to curb its generation. The tiles were produced by mixing fine sand with molten plastic waste in different proportions. The physical and mechanical properties of the floor tiles such as water absorption, density, tensile and compressive tests, modulus of elasticity as well as impact strength and friction tests were investigated. The water absorption ranged from 0.02 - 0.38 %(m/m), while the density varied between 998.5 and 1289 kg/m3. The tensile strength and modulus of elasticity fell within the range of 0.050 to 0.232 MPa and 0.924 to 2.806 MPa, respectively. This result proved the applicability of recycled plastic waste in the formulation of floor tiles.

The desire to design and develop machine with high versatile method of physically separating mineral particles based on differences in the ability of air bubbles to selectively adhere to specific mineral surfaces in mineral/water slurry using indigenous materials is constantly evolving to meet specific requirements of specific industrial plant. Therefore, the aim of this study was to design and construct a 0.012 m 3 capacity laboratory froth flotation machine using locally sourced materials with the view to promoting indigenous technology in Nigeria. The construction was based on parameters established from literatures. The design was done using Auto-Cad version 7 software. The machine was built of different components which are corrosion resistant, easy to access and can be assembled and disassembled when the need arises. The machine was constructed such that its height can be adjusted to suite flotation characteristics of different materials. The machine was of height 1.5 m and designed to operate at batch condition. A flotation tank of capacity 0.012 m 3 holds the pulverized pulp mixture for flotation operation. The flotation tank was equipped with regulated speed agitator shaft and stirrer assembly to condition the pulverized pulp mixture. Regulated air flow from a 0.02 m 3 /min compressor was also applied to the mixture in the cell for effective hydrophobicity and hydrophilicity.

The presence of heavy metal contaminants in wastewater effluents has become a great threat to living creatures and the environment. In this study, the application of thermodynamics and column studies for Pb2+, Cd2+ and Mn2+ metal ions removal in multicomponent aqueous solution using low-cost bentonite clay was investigated. Evaluation of enthalpy (∆Ho), entropy (∆So) and Gibbs free energy (∆Go) revealed that heavy metals adsorption was endothermic and spontaneous as temperature increased from 30 to 65 oC. The column performance was determined at 0.05m adsorbent bed depth, 0.023 and 0.04 mL/s flow rates. The influent concentration was 10 and 50 ppm while the breakthrough time was between 0.83 and 8 hr. The maximum uptake of metal ions was 2.2 mg/g for Pb(II), Mn(II) was 0.4 mg/g and 1.7 mg/g for Cd(II). The result showed the potential of bentonite clay as a candidate for toxic metal ions adsorption in wastewater.