Potentially toxic elements (As, Cd, Cr, Hg, and Pb), their provenance and removal from potable and wastewaters

This chapter covers the natural occurrence of potentially toxic elements in the environment, particularly geological sources, and their impact on groundwater quality. The toxicity of the main elements is covered, as well as guidelines to their toxicity and the control limits in drinking water. Finally, the main methods for the removal of toxic elements from groundwater, drinking water, and wastewater are covered, as many of the methods are the same, and the overarching goal of each is the protection and health of the hydrosphere.