A review on the multifaceted effects of δ-MnO <sub>2</sub> on heavy metals, organic matter, and other soil components
Haoran Hu, Xiangdong Li, Xinyu Gao, Lei Wang, Bo Li, Fangdong Zhan, Yongmei He, Qin Li, Xinran Liang
Abstract
Manganese oxide minerals are prevalent in soils and play a pivotal role in the immobilization of heavy metals and the transformation of materials. Characterized by their low point of zero charge and numerous active adsorption sites, manganese oxides effectively accumulate heavy metals such as lead (Pb) and cadmium (Cd) from contaminated environments. Different manganese oxides, mediated by Mn(ii), vary in their capacity to enrich heavy metals. Their distinctive nanostructures can be harnessed to create composite materials that boast enhanced adsorption properties and environmental sustainability. As a highly reactive element in soil, manganese engages in multiple reactions with soil organic components and inorganic ions through processes like oxidation-reduction. This activity aids in the elimination of organic pollutants and facilitates carbon sequestration through various mechanisms. This article explores the metal enrichment capabilities of manganese oxides and their influence on soil physicochemical properties, enhancing our understanding of how these oxides adsorb metallic elements and interact with soil components. Such knowledge is crucial for advancing heavy metal remediation strategies and comprehending the biogeochemical processes within soil environments.