Heavy metals' removal from aqueous environments using silica sulfuric acid

There is a growing environmental and health concern associated with contamination by heavy metals. It has also been intensified due to an increase of the exposure to such pollutants as a result of industrial and technological growth. Therefore, it is necessary to remove heavy metals in contaminated water to eliminate the associated risks. This study focused on the removal of heavy metal ions using silica sulfuric acid (SSA). A comprehensive study was conducted to assess the effect of different factors on the adsorption by SSA as well as selectivity properties of the adsorbent, kinetic and thermodynamic studies of the adsorption process. A batch test was used to remove heavy metals from a multi-element solution containing Ni(II), Pb(II), Mn(II), Cu(II), and Cd(II). The results showed that removal rate reached its peak at pH, string time, and adsorbent amount equal to 8, 60 min, and 0.04 g/mL of solution, respectively. The removal efficiency of Ni2+, Cd2+, Mn2+ dropped by increasing the volume of solution and smoothed at 150 mL while the removal of Pb2+ and Cu2+ did not vary with the volume. The removal efficiency by SSA was decreased as Pb > >Mn > >Ni >= Cu > Cd. In general, SSA successfully removed heavy metals from contaminated water.