Characterization and application of wood-ZrO2 sorbent for simultaneous removal of chromium (III) and chromium (VI) from binary mixture

Abstract

Abstract A new woodchips-ZrO2 biosorbent (W-ZrO2) was synthesized using wood residue material generated from the oak tree (Quercus robur) during furniture manufacturing. Biosorbent was tested for the simultaneous removal of both chromium (Cr) ions: Cr(III) and Cr(VI), in the binary component solution. Biosorbent characterization was performed by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). To define optimal process parameters for simultaneous removal of both Cr species, effects of pH, temperature, sorbent dosage and Cr ions concentration on the sorption process were investigated. Sorption of Cr ions onto W-ZrO2 was highly pH-dependent. Optimal pH for simultaneous removal of both Cr(III) and Cr(VI) ions is 4.0 with removal efficiency over 99.5 % in both cases. Equilibrium experimental results are the best fitted by the Langmuir sorption isotherm model. The maximal sorption capacities of the biosorbent for simultaneous removal of Cr(III) and Cr(VI) ions in binary-component system are 16.18 and 83.52 mg g−1, respectively. The present study shows that using wood residue material to produce a low-cost sorbent can effectively decrease the water pollution simultaneously removing both chromium species from water and also reduce wood waste and increase reuse/recycling options.