8. Remediation of Heavy Metal Pollutants of Industrial Effluents and Environmental Impacts

A variety of effectual, non-polluting, and economical nanomaterials have been developed, having special capabilities for the potential purification of industrial effluents. Improper disposal of effluent generated from different industries or mining activities affects the ecosystem through increased metal pollution and biodiversity loss. It has significant detrimental effects on the health of aquatic ecosystems through increased nutrient loads that can lead to eutrophication and temporary oxygen deficits and also a serious negative impact on ecosystems due to heavy metals (HMs) bioaccumulation in the food chains. Nano-metal silicate tubes (NMSTs) synthesized through the silica garden route are considered important materials for the removal of HMs from industrial effluents. The present chapter is emphasized on nano calcium silicate precipitation tubes (CaSPT) as HMsl (Zn(II), Cd(II), Cu(II), Pb(II), and Cr(III)) adsorbents in an aqueous medium to identify its application as water purifier after thorough physicochemical characterization. With the increase in initial metal ion concentration, the absorption process moved towards irreversibility. Adsorbent dose and its initial concentration has significant impacts on adsorption, and it varies non-linearly. CaSPT was identified as a superior adsorbent of HM ions as compared to the conventional non-tubular calcium silicate tube due to its high surface area. Nano CaSPT was successfully applied in an effluent sample collected from the electroplating industry to remove Cr(III), Zn(II), and Pb(II).