Removal of zinc and copper ions from water by chitosan coated permutite granules

Abstract

Permutite and chitosan are known to be safe compounds that effectively remove metal ions from wastewater. In this study, chitosan coated permutite granules were prepared as a new adsorbent and then optimized and applied to the removal of zinc and copper ions from feed water from a local plant. TG-DTA and SEM analysis illustrated that the modified permutite was not simply a mixture, but a novel adsorbent with better thermal stability than unamended permutite. The best ratio of chitosan to permutite was 1:80 (M1) for zinc and 1:40 (M2) for copper, which could remove 58.8% and 50.2% of the ions in 30 min, respectively. M1 could decrease the zinc ions at an initial concentration of 2 mg/L by 99% in 60 min while M2 removed 50% of copper ions in 150 min, which were both improvements over unamended permutite or chitosan. The difference between zinc and copper ions adsorption on the composed material was mainly attributed to the low initial concentration and the difference in the adsorption capacity of permutite for these ions. The chitosan coated permutite granules could effectively adsorb metal ions in low concentrations and remediate micro-polluted water (with metal ions) to meet applicable standards under controlled conditions.