Binding of some heavy metal ions in aqueous solution with cationized or sulphonylated starch or waste starch

Abstract

Contamination of water by heavy metal ions is a severe environmental problem. In this study, starch-or waste-starch-based binding agents were used to bind heavy metal ions in aqueous solutions in order to prevent the precipitation of metals in alkaline conditions (pH 10). This is a useful feature, e.g. when ultrafiltration is used as a purification technique for a low metal concentration containing wastewaters. The studied binding agents were water-soluble cationized depolymerized barley starch (CDS) prepared by depolymerization and subsequent cationization, sulphonylated starch (SS) and cationized depolymerized potato peel waste (CW), all of which have not been used previously as binding agents. The studied modified starches were investigated in the binding of Fe(III), Cu(II), Zn(II), or Ni(II) ions in aqueous solutions by utilizing inductively coupled plasma-optical emission spectrometry (ICP-OES) as an analytical method. Cationized depolymerized starch bound 80-100% of Fe(III), Zn(II), and Cu(II) ions and SS bound 85-95% of Fe(III), Zn(II), and Ni(II) ions when 0.5 mM metal ions solutions and molar ratio of starch:metal 0.66:1 were used. Cationized depolymerized waste starch bound Cu(II) ions 78-94% (0.25-2.5 mM metal ion solutions prepared with distilled or lake water) in aqueous solution with molar ratio of starch:metal varying from 1:1 to 3:1.

Absorbed Pb2+ and Cd2+ Ions in Water by Cross-Linked Starch Xanthate

“…an important controlling parameter in the heavy metal ions adsorption process [19,20]. The cross-linked starch xanthate samples were put into the Pb 2+ and Cd 2+ solutions over a pH range of 2-9 at room temperature to investigate the influence of pH on Pb 2+ and Cd 2+ ions adsorption property.…”

Spectroscopic study of natural and synthetic polysaccharide sulfate structures

“…Aside from the aforementioned possibilities arising from the biological effects of polysaccharide sulfates, other applications have also been suggested for the material. Anionic starches could be useful as metal complexing agents , which makes starch sulfate interesting for instance from the point of view of benign waste water treatment . The compound could also act as a biodegradable and renewable solid acid catalyst and as superabsorbent .…”

Nutritional Quality of the Most Consumed Varieties of Raw and Cooked Rice in Spain Submitted to an In Vitro Digestion Model

“…The presence or formation of resistant or low digestibility starches may contribute to establishing a stronger metallic and metalloid element-retention than might be expected to fast digestibility starches. Recent works demonstrated the capacity of some modified starches to form metallic or metalloid elements-complexes [54], thus, a lesser grade these modifications may occur spontaneously in rice, which could explain the higher presence of these metallic and metalloid elements in the non-digestible fraction of rice. Different letters in the same row indicate significant differences by ANOVA test (p < 0.05).…”