Characterization and improvement in physical, chemical, and biological properties of mine wastes

Degradation of land resources as a result of mining activities poses serious threat to the environment. It has been estimated that around 0.4 × 10⁶ km² area of land is impacted by mining activities around the world (Hooke and Martín-Duque 2012). Unfortunately, a significant percentage of this area has never been reclaimed, which poses health risks to ecosystems and humans. Often, these wastes contain hazardous substances such as heavy metals, organic contaminants, radionuclides, and crushed limestone, where the latter could become a potential source of atmospheric CO₂ emission. Thus, they not only pose serious risk to the groundwater and surface water, but also to the atmosphere (Wijesekara et al. 2016). In order to tackle the issues related to mine wastes and manage the affected sites sustainably, an appropriate physical, chemical, and biological characterization of waste materials becomes very prudent. Due to the lack of both above- and below-ground biodiversity, mine waste sites are very poor in organic matter content. This in return leads to poor seed germination, plant growth, and vegetation establishment. In many cases, the associated toxic contaminants also seriously compromise the soil health, microbial life, and plant growth (Castillejo and Castelló 2010, Larney and Angers 2012). This chapter describes the physicochemical characteristics of mine wastes, including spoil, tailings, and overburden, by underpinning their source-property relationships. The value of readily available biowaste resources, including biosolids, composts, and manures, in improving such physicochemical properties of mining-impacted soils/sites is also discussed