Removal of toxic chromium(VI) ions from aqueous solutions using green walnut shells

Hexavalent chromium ion and its derivatives are potential pollutant due to their mortal effects. Therefore, it is essential to remove these components from wastewaters before disposal. In this article, green walnut shell (GWS), a horticulture solid waste, was used as a new and low-cost material for the removing of Cr(VI) from aqueous solutions. The efficiency of this new biomass was studied under different experimental conditions such as initial solution pH,initial GWS amount, contact time, GWS particle size, initial Cr(VI) concentrations and ionic strength of the solution. It was found that the mechanism of removing Cr(VI) by GWS is adsorption-coupled reduction. The best removal condition for a 50ml solution of 10 mgL-1 Cr(VI) was obtained in initial pH of 3.6 by 0.3g GWS, in this case the removal percentage was 95%.

کلیدواژه ها:

Adsorption-coupled reduction ، Chromium(VI) ، Low-cost biomass ، Green walnut shell