Removal of Cr(VI) and Cu(II) from wastewater by an Argopecten irradians shell powder adsorbent

Abstract

The ability of the shell powder of Argopecten irradians to remove Cr(VI) and Cu(II) ions from aquatic systems was evaluated. The adsorption efficiency was very high for Cu(II), at approximately 99.04%, while for Cr(VI), it was not higher than 24.03%. The adsorption rate of Cr(VI) was affected by the pH, feeding amount, stirring time, calcination temperature and initial Cr(VI) ion concentration. The experimental results indicate that the optimal Cr(VI) absorption rate was 32.86% of Cr(VI) within 1.5 h at a pH of 3 and a 200 mg/L initial Cr(VI) concentration on shell powder acidifie, using hydrochloric acid and calcination at 300°C to promote adsorption. Langmuir and Freundlich models were used to analyse the isotherm data of Cr(VI) and Cu(II). The Freundlich model was suited to Cr(VI) adsorption, while the Langmuir model fit Cu(II) adsorption.