Pectin is an acidic polysaccharide constituted by monomer units of galacturonic acid. It is a main component of peel fruits where is present as protopectin. Due to the presence of a high number of carboxylic binding sites in its structure, pectin (Pect) shows a good sequestering capacity towards metal ions. Pectin has been proposed as a sorbent to remove metal ions from aqueous solutions. In this work the ability of pectin on solid phase to remove Cd(II) and Cu(II) from aqueous solutions has been evaluated. To this end, a powder of a commercial pectin, (esterified potassium salt from Citrus fruit) was encapsulated in a polymeric matrix of calcium alginate (CA) at different ratios of pectin to obtain spherical beads of calcium alginate.The different ratio pect-CA, contact time, different number of beads on solution anddifferent initial pH has been studied in order to obtain kinetic data of metal adsorption on the biosorbent. To better characterize the kinetic behavior the experimental data were fitted by Lagergren (pseudo-second order) equation.Results showed that calcium alginate, used as blank, is able to remove cadmium andcopper and the presence of pectin into the beads enhance the sorption capacity. Thehighest sorption rate was obtained with beads with the highest percentage of pectin(2%). The optimal contact time was found to be two hours and the most favourableinitial pH is around 5.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2008|