Removal of Lead and Cadmium from Polluted Water Using Environmentally Safe Materials

Abstract

Heavy metals that exist in municipal wastewater can cause many problems for human hygiene and environment. Therefore, the metals need to be removed from wastewater before being used in irrigation. Materials of high surface reactivity; such as alginit, shale and iron oxide are used as potential sorbents to eliminate Pb and Cd from polluted water. In remediation studies, these materials were added to Pb and Cd polluted water at addition ratios of 1:10000, 1:1000 and 1:100 (remedy agents: polluted water). The mixtures were then gently agitated and submitted to different equilibrium periods of 1, 5 and 24 h. The results showed the efficiency of tested agents (shale, alginit, and iron oxide) in the removal of Pb and Cd from polluted water containing various concentrations of 5, 10 and 50 mg/l. Shale was able to reduce Pb and Cd concentration from 5 to 1.14 and 0.34 mg/l, respectively, in a reaction period of one hour. Shale, alginit and iron oxide, reduced the initial concentration of; 10 mg Pb/l to 0.98, 0.46 and 0.57 mg/l; and of 50 mg Pb/l to 0.21, 6.5 and 1.68 mg/l; respectively. Shale was the most effective material in decontamination of heavy metals polluted water and it could be recommended to be used to decontaminate wastewater. This research aims to use a non expensive, environmentally safe, and efficient technique to remove heavy metals from industrial wastewater to leave them free and suitable for discharging to sanitary sewer system.