Enhancement of chromium removal from water by bioadsorption using edta-treated rice straw

Abstract EN

Using factorial experiments, rice straw of ١g or ٢g weight was immersed into ١٠٠ ml of water solution of different concentrations of Cr (٢٥, ٥٠ and ٧٥ mg Crl), in a form of Cr-chloride ‘CrCl٣.

٦H٢O’.

The contact and shaking time intervals were ٦٠, ٩٠ and ١٢٠ minutes and the solution pH values were ٥, ٧ and ٩.

One experiment was conducted for each of the ١g and ٢g nonethylenediamine tetra acetic acid (EDTA)-treated straw and one experiment for each of the ١g and ٢g EDTA-treated straw.

In terms of the amount of Cr removed from solutions, it increased as the initial concentration increased.

In terms (%) removal from the initial concentration, the removed portions decreased as the initial concentration increased.

Treating the straw with EDTA and increasing the time of contact enhanced the removal.

High removals occurred with the neutral or alkaline pH.

Lowest (%) removal was ٢٤% for the treatment of ١g non-EDTA straw of the ٧٥ mg Crl solution of pH ٥ and the shortest contact time of ٦٠ min.

Highest (%) removal of ١٠٠% was obtained by the treatment of ٢g EDTA straw in the ٢٥ mg Crl of either pH ٧ or ٩ and longest contact time of ١٢٠ min.