REMOVAL OF HEAVY METALS FROM WASTEWATER USING CAUSTIC CALCINED MAGNESIA

Abstract

Slovakia holds 4th to 5th position in the world with respect to the supplies and mining output of magnesite. The most important product of natural magnesite processing is magnesia. While dead-burnt magnesia is used for producing basic refractory materials for metallurgy and cement industry, caustic calcined magnesia (CCM) founds new applications in industries, agriculture and environment protection. Use of CCM, due to its alkaline nature, as a reactive material for remediation of wastewaters, can provide all advantages of methods based on neutralization (pH adjustment) by lime. In this study, CCM was experimentally tested as a reactive material for the removal of cations Cu2+, Zn2+ and Ni2+ from wastewaters. The effects of chemical composition of model wastewaters tested and water-to-CCM weight ratio were investigated. The results have shown that CCM is a suitable material for the removal of heavy metals, especially copper, zinc and nickel, from acid wastewaters. The efficiency of cation removal up to 100% has been observed.