Unmodified starch as water-soluble binding polymer for chromium ions removal via polymer enhanced ultrafiltration system

Background: in this study the removal of chromium (iii) and chromium (vi) ions are investigated via polymerenhanced ultrafiltration under important process parameters. this study proposes the use of unmodified starch as anovel polymer in the ultrafiltration process and its performance on the removal of chromium ions was comparedwith a commonly used polymer, polyethylene glycol.methods: the experiments were carried out at 1.5 bar and different ph values by using 10 kda hollow fibermembrane operating in a cross-flow mode.results: the best chromium ions removal obtained approached 99% for chromium (iii) ion by unmodified starch atalkaline ph region and at ph 7 for chromium (vi) ions retention by polyethylene glycol. permeate flux behavior arefluctuated for both chromium ions tested at high metal ion concentrations. low concentration of unmodifiedstarch is applied to reduce gelatinization behavior.conclusions: the findings suggest that binding of chromium ions by unmodified starch is related to granulestructure which is probably a principal indicator of the non-ionic behavior of unmodified starch.