Biosolids Enhance Mine Site Rehabilitation and Revegetation∗

Globally, around 10 × 107 tons year−1 of biosolids is generated from wastewater treatment facilities. Biosolids contain significant amounts of organic matters and nutrients. Therefore, biosolids can be used to improve infertile and degraded soils in certain mine sites. Shortfalls in topsoil, heavy metal–rich tailings and drainage, residual soils with poor physical properties, and low–organic matter soils are common consequences of degraded mine soils. These issues adversely affect soil health including microbial activity, flora, and fauna, thereby hindering reestablishment of the lost ecological integrity. Rehabilitation has been achieved in a number of mine sites by incorporating biosolids, which demonstrated sustainable remediation of these sites. Improvements in the biological, chemical, and physical properties of degraded lands are associated with these rehabilitation cases. Furthermore, these improvements enhance the nutrient cycling, water purification, and restoration of plants and increase the recreational value of the land, thereby helping in the emergence of novel ecosystems. This chapter describes the composition of different types of biosolids and their generation, benefits, and current regulations for use, particularly regarding mine site rehabilitation and environmental contamination issues including human health concerns. Finally, challenges and future research needs are identified in terms of the minimization of environmental complications and sustainable use of biosolids.