Reuso de residuos de la industria metal-mecánica para el tratamiento de efluentes que contienen contaminantes reducibles

Abstract

Metal mechanical industry produces annually tons of waste composed mainly of iron shavings. This research evaluates the feasability of using those iron shavings for reduction of Cr(VI) in wastewater. Analysis of shavings showed they were composed essentially of iron (>90% peso), with other metal at trace levels. Leaching tests were performed to verify the shavings do not release toxic components in contact with wastewater. Finally, the shavings were used to reduce Cr(VI); 95% of Cr(VI) was reduced in solutions containing initial levels of 100-300 mg/L. Reduction is not strongly affected by presence of carbonate, sulphides, chloride and organic compounds. This is a very attractive process, which uses a common waste to reduce water pollution in a cost-effective way.