MODIFICATION OF COAL-BASED SORBENTS FOR THE PURPOSE OF REMOVING HEAVY METALS

Abstract

Sources of environmental and wastewater pollution with heavy metals include chemical detergents used in everyday life, as well as various pollutants discharged from large industrial factories. Even small amounts of heavy metals, including copper and lead ions, can cause significant harm to the human body. In order to reduce the harmful effects of heavy metals, various methods and approaches for their removal have been investigated. Based on a comparison of many scientific studies, the beneficial properties of natural sorbents have been identified. According to our research, it was found that coal exhibits the highest sorption capacity among natural sorbents. In addition, elemental analysis of both raw and modified coal was performed, showing changes in carbon and oxygen content, as well as a reduction in mineral impurities. These changes are explained by the formation of oxygen-containing functional groups on the coal surface and an increase in active sites. Thus, modification of hard coal with hydrogen peroxide demonstrated that its ability to remove heavy metals and its static exchange capacity depend on temperature (60–120 °C), contact time (60–120 minutes), and concentration (2.5 mol). Under these optimal conditions, the sorption capacity increases by approximately 40%.