Sustainable Approach for Nickel and Cadmium Removal: Adsorption Experiments Using a Low-Cost Material from Industrial Sites

摘要

The adsorption process may be considered as a cheap technique for removal of metals in low concentration. Among the materials, the use of biomass has been increased due to low costs, technical feasibility, and environmental benefits. The goal of the present study was to study the adsorption of Cd(II) and Ni(II) ions using a biomass from contaminated sites. The effect of pH, metal ion concentration, biomass pretreatment, and time in batch were evaluated. The biomass was analyzed in Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Langmuir and Freundlich isotherms were evaluated. Results have demonstrated that biomass may be used for adsorption of these ions. In addition, pretreatments can intensify the activation of functional groups present in the biomass. The adsorption of Cd(II) and Ni(II) ions was higher for autoclaved biomass (294 mg/g and 10 mg/g) than activated charcoal (187 mg/g and 2 mg/g) and better fitted for the Langmuir isotherm. At pH 7.0 and 1.0 g/L, the removal of Cd(II) achieved 55% by autoclaved biomass, while activated carbon achieved 13%. It demonstrates the importance of low-cost adsorbents, suggesting the possibility for industrial activities to use contaminated sites as raw material for wastewater treatment.