Current physicochemical treatment technologies available for remediation of different types of heavy metals from wastewater

Although heavy metals are long familiar for their toxicity and carcinogenicity, they are being introduced into the aquatic systems from various industrial operations. The remedial measures of heavy metals are of great importance owing to their recalcitrant character and persistence in the environment. Higher accumulation and prolonged exposure of heavy metals cause deleterious health effects on humans as well as various aquatic life forms. To treat heavy metal discharges from industrial wastewater, technologies for the reduction of toxic substances are often required to meet technology-based treatment standards. This chapter discusses various types of newly developed and freshly applicable treatment processes and technologies for the removal of heavy metals from various industrial wastewaters. Physicochemical removal processes include chemical precipitation, coagulation and flocculation, flotation, ion exchange, reverse osmosis, ultrafiltration, ion exchange, membrane filtration, electrochemical treatment, photocatalysis, and nanotechnology. Besides, chemical methods are considered to be the most suitable treatment methods for toxic inorganic compounds produced by various industries that cannot be removed using any biological and physical techniques.