Preparation, characterization and application of a Ce-Ti oxide adsorbent for enhanced removal of arsenate from water.

Different metal doped TiO(2) adsorbents were prepared through the precipitation and hydrolysis-precipitation methods. The novel Ce-Ti oxide adsorbent obtained by the hydrolysis-precipitation had much higher sorption capacity for As(V) than both the pure titanium dioxide and cerium oxide adsorbents, and the preparation conditions including the Ti/Ce molar ratio and polyvinyl alcohol (PVA) content were optimized. Environmental scanning electronic microscopy (ESEM) and X-ray diffraction (XRD) spectroscopic investigations revealed that the amorphous Ce-Ti hybrid adsorbent was composed of some nanoparticles in the size range of 100-200 nm, which aggregated to form the porous hybrid adsorbents, and the amorphous compositions and the small nanoparticles were related to the high sorption capacity for As(V). Batch sorption experiments including sorption kinetics, isotherm, effect of pH and competitive ions were investigated. The Ce-Ti adsorbent exhibited high sorption capacity for As(V) at pH below 7. Column studies showed that about 72,085 bed volumes of As(V) solution at the concentration of 50 microg L(-1) and pH 6.5 were filtered when As(V) concentration in the effluent increased to 10 microg L(-1), and the average sorption capacity of As(V) on the Ce-Ti adsorbent was about 9.4 mg g(-1).