Adsorption of Chromium (VI) onto Metakaolin: Isotherms, Modelling and Optimization

Contamination of water bodies by heavy metals poses serious threats to public health in many countries. Heavy metals such as chromium, lead, cadmium, and mercury are toxic, non-biodegradable, soluble in water and persistent in the biogeosphere In water, chromium mainly exists in two oxidation states: trivalent chromium (Cr(III)) and hexavalent chromium (Cr(VI)). Hexavalent chromium is much more toxic than the trivalent chromium Hexavalent chromium affects kidneys, respiratory system, eyes, skin and liver. The International Agency for Research on Cancer (IARC) listed Cr(VI) as a group I human carcinogen According to the World Health Organization (WHO), the recommended a maximum concentration of Cr(VI) in drinking water is 0.05 mg/L. The LD50 for Cr(VI) is in the range of 50 to 150 mg/kg