Mechanisms and Approaches for the Removal of Heavy Metals from Acid Mine Drainage and Other Industrial Effluents

Contamination of surface and underground water resources with heavy metals has been an issue of paramount concern in recent decades. This is attributed to the magnitude of impacts that heavy metals pose to terrestrial and aquatic living organisms on exposure. Furthermore, mining activities and metal processing interventions generate huge volumes of heavy metal-laden streams to different receiving environments. Similarly, the nature of chemical species present in the water bodies depends on the nature and type weathered and host minerals. On that regard, scientists and engineers have developed a number of prudent and pragmatic technologies for the removal of these pollutants from water bodies. Different techniques that rely on different mechanisms and approaches are often employed for the removal of heavy metals from wastewater, and they include neutralization, adsorption, filtration, and phytoremediation, among others. These technologies have been reported to present different advantages and disadvantages on application. This chapter will give an in-depth discuss on different mechanisms and approaches employed for the removal of pollutants from wastewater. Furthermore, sustainable approaches for valorization and beneficiation of waste effluent streams will also be discussed in this chapter, including preliminary challenges of beneficiation. This will impart value to wastewater via the conversion of waste into a resource, thus enabling them to perceive these wastewater streams as a resource not waste. Recovery of heavy metals from wastewater can aid in offsetting the running cost of the treatment process, hence making it self-sustainable and eco-friendly. This will also foster the concept of circular economy and sustainable development. This chapter will also highlight the advances made in terms of acid mine drainage management and heavy metals treatment. In particular, the advancements, failures, challenges, and future research avenues will also be unpacked in this chapter. This will be used as an avenue to guide future research and to identify potential opportunities for future research in wastewater treatment.