Enhanced copper removal from aqueous solution by hydrous TiO2/zeolite composite

ABSTRACT

Hydrous titanium dioxide was impregnated on the surface of zeolite to obtain a kind of hydrous TiO₂/zeolite (HTiO₂/ZFA) adsorbent using the hydrothermal method. HTiO₂/ZFA was characterised by scanning electron microscopy combined with energy-dispersive spectrometer, X-ray diffraction, Fourier transform infrared, particle size distribution; and the pH of zero point charge measurement and its performance for Cu(II) adsorption were investigated. It was shown that Ti was not inserted into the skeleton of ZFA and hydrous TiO₂ loaded on the surface was amorphous. The pHzpc of HTiO₂/ZFA decreased to pH 5.5 from pH 6.5 of ZFA. Cu(II) adsorption was favoured in a pH range of 3.0–6.0, and 90% copper could be removed in first 30?min for 60?mg?L^–1 Cu(II) solution. The Langmuir isotherm model could well describe the adsorption isotherm data and the maximal Cu(II) adsorption capacity reached 251.9?mg?g^–1. Moreover, the HTiO₂/ZFA could be desorbed by HCl solution for further use, which implied an effective application in wastewater treatment.