Removal of As(V) and Hg(II) ions from simulated wastewater using natural and modified Ca - bentonite

Using natural and modified Ca-bentonite as an adsorbent to observe a satisfactory trend in the removal of heavy metal ions As(V) and Hg(II) from simulated wastewaters. In this original scientific paper, Ca-bentonite was modified in two ways, thermally activated at a temperature of 300 °C for 3 hours and acid activated with HCl and H2SO4, molar concentrations 0,4 mol/L. Ca-bentonite used in this original scientific work was used from the Shipovo mine (Šipovo mine), Bosnia and Herzegovina and proved to be an excellent bioadsorbent for the removal of present ions from simulated wastewaters. Also this is eco-friendly adsorbent and low costed compared to other expensive adsorbents. Due to its chemical composition in which two oxides predominate, namely SiO2 (48.28 mass %) and Al2O3 (23.04 mass%), it can be concluded that Ca-bentonite from the Shipovo mine (Šipovo mine), Bosnia and Herzegovina belongs to the group of refractory materials. The highest removal efficiency of As(V) ions expressed in % was 75.11 at the initial concentration of 1.5 mg/L and was recorded using HCl acid-activated Ca-bentonite. The efficiency of Hg(II) ion removal was the highest using thermally activated Ca-bentonite and this value was 99.66% at an initial concentration of 1 mg/L.