Abstract
Abstract : Many developing countries around the world still lack access to clean fresh water. This refers to water that is free from contaminants as it is highly essential for human livelihood and environment. In countries along the coast, ocean water is the most available water resource; however, it comes at a salt concentration that is very high for human consumption. Most of available water has a salinity of up to 10 000 ppm and seawater consists of dissolved salt concentrations of about 35 000-45 000 ppm. This lead to desalination process being used as an option to treat seawater and this has become one of the most important processes of providing fresh water in developing countries. Therefore, the aim of this study was to investigate the practicability of using nanometer metal oxides and polymer/NMO composite as the potential adsorbents for adsorption desalination of seawater. The quantification of analytes in sample solutions was done using the inductively-coupled plasma atomic emission spectroscopy (ICP-OES). Nanometal oxide composites such as Fe2O3-SiO2, SiO2/Nb2O5/Fe2O3, Fe2O3-SiO2-PAN and zeolite/Fe3O4 adsorbents were used for the adsorptive desalination of saline water. Fe2O3-SiO2, SiO2/Nb2O5/Fe2O3 and zeolite/Fe3O4 adsorbents were prepared using a sol gel method whereas Fe2O3-SiO2-PAN nanocomposite was obtained using in-situ preparation method. The adsorbents were characterized using different techniques such as scanning electron microscopy (SEM), x-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET). SEM image of Fe2O3-SiO2 nano composite showed the porous morphological structure. The Fe2O3-SiO2 showed partial crystalline pattern due to silica oxide that has pure amorphous structure, whereas the SiO2/Nb2O5/Fe2O3 has an amorphous structure. TEM structure of α-Fe2O3 has dominant shapes of spherical and some few cubic and hexagonal shapes, the hexagonal shape were also observed on Fe2O3-SiO2 nanocomposite material. SiO2/Nb2O5/Fe2O3 adsorbent resembled a core-like structure. The TEM result of Fe2O3-SiO2-PAN revealed that the crystalline Fe3O4 nanoparticles were encapsulated with PAN polymer that suggests the core-shell structure. EDX-mapping analysis showed the uniform elemental distribution which suggests the successful preparation of the in-situ method...
Ph.D. (Chemistry)