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

Nurul Huda Baharuddin,Nik Meriam Nik Sulaiman,Mohamed Kheireddine Aroua

doi:10.1186/2052-336x-12-61

Nurul Huda Baharuddin, Nik Meriam Nik Sulaiman + Show 1 more

Open Access

https://doi.org/10.1186/2052-336x-12-61

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Abstract

BackgroundIn this study the removal of Chromium (III) and Chromium (VI) ions are investigated via polymer enhanced ultrafiltration under important process parameters. This study proposes the use of unmodified starch as a novel polymer in the ultrafiltration process and its performance on the removal of chromium ions was compared with a commonly used polymer, polyethylene glycol.MethodsThe experiments were carried out at 1.5 bar and different pH values by using 10 kDa hollow fiber membrane operating in a cross-flow mode.ResultsThe best chromium ions removal obtained approached 99% for Chromium (III) ion by unmodified starch at alkaline pH region and at pH 7 for Chromium (VI) ions retention by polyethylene glycol. Permeate flux behavior are fluctuated for both chromium ions tested at high metal ion concentrations. Low concentration of unmodified starch is applied to reduce gelatinization behavior.ConclusionsThe findings suggest that binding of chromium ions by unmodified starch is related to granule structure which is probably a principal indicator of the non-ionic behavior of unmodified starch.

Highlights

In this study the removal of Chromium (III) and Chromium (VI) ions are investigated via polymer enhanced ultrafiltration under important process parameters
Materials The experiment was carried out using unmodified starch in powder form and polyethylene glycol (PEG 200) as selected water soluble polymer in the form of solutions from ACROS Organics, along with sodium hydroxide and hydrochloric acid for pH adjustment. 1000 mg/l of Cr (III) and Cr (VI) ions were used as metal solutions
Throughout this study, it was shown that complexationultrafiltration process has a great potential for chromium ions removal by engaging with two valuable polymers such as unmodified starch and PEG from synthetic

Summary

Introduction

In this study the removal of Chromium (III) and Chromium (VI) ions are investigated via polymer enhanced ultrafiltration under important process parameters. This study proposes the use of unmodified starch as a novel polymer in the ultrafiltration process and its performance on the removal of chromium ions was compared with a commonly used polymer, polyethylene glycol. Most chromium species are present in oxidation ranges of -2 to +6 [3]. In order to address this problem, current technology has come up with an alternative, which is Polymer Enhanced Ultrafiltration (PEUF), described previously [5,6,7]. In this process, adsorptive mechanism of polymers efficiently bound with metal ions form molecular complexation and through the ultrafiltration process, this macromolecular is rejected. A water soluble polymer, namely unmodified starch and polyethylene glycol (PEG) which mostly has no negative impact on our environment were used

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