Removal characteristics of manganese-coated solid samples for Mn(II)

Manganese-coated sand (MCS) and manganese-coated sericite (MCSe) were prepared at pH 4 and 9 (MCS4, MCS9, MCSe4 and MCSe9) and applied in the treatment of wastewater containing soluble Mn2+ in batch experiments under various pHs. The amount of Mn2+ adsorbed by manganese-coated solids increased as the solution pH increased from pH 4 to 11. In order to compare Mn2+ sorption onto manganese-coated solids in the presence of hypochlorite, 4 mg/L of NaClO was added into Mn2+ solution. It was observed that the presence of sodium hypochlorite dose significantly enhanced the uptake of Mn2+ from aqueous Solutions for the entire pH range studied i.e., pH 4.0 to 11.0. In adsorption isotherm experiment, the results were fitted reasonably well for the Freundlich equation. Mn2+ breakthrough time in the effluent from both MCS and MCSe columns in the presence of hypochlorite was greatly enhanced. Among these manganese-coated solids, MCSe4 showed the highest adsorption capacity. Therefore, MCSe4 was identified as a better adsorbent and filter material for the treatment of wastewaters containing Mn2+.