Cadmium adsorption on manganese modified bentonite and bentonite–quartz sand blend

• Bentonite and quartz sand were modified by manganese oxides.
• Study focuses on novel preparation of mixture based on bentonite and quartz sand.
• Relatively low-cost sorbents for removing of hazardous compounds were prepared.

The bentonite from deposit Stará Kremnička and quartz sand from deposit Šaštín both from Slovakia were modified by manganese oxides in order to increase their sorption properties. At first, the natural bentonite was activated by Na2CO3. The manganese oxides were precipitated on natrified bentonite and quartz sand grains by means of reductive procedure. The obtained materials were characterized by the X-ray diffraction analysis. The surface and pore properties of the studied samples were gained by the nitrogen adsorption measurements. The size and shape of investigated particles were monitored through the Scanning Electron Microscope (SEM). The batch sorption experiments of Cd2 + from aqueous solutions were performed on natural materials and modified mixtures. The measured sorption values were well described by the linearized Langmuir sorption model. The modification by manganese oxides enhanced the adsorption efficiency of all initial materials.