Adsorption of some heavy metal ions by used different immobilized substances on silica gel

• Main Author: Mohamed M. Shahata
• Format: Article
• Language: English
• Published: Elsevier 2016-11-01
• Series: Arabian Journal of Chemistry
• Subjects: Poly(8-hydroxyquinoline); Immobilization; Silica gel; Heavy metals; Cu(II); Fe(III)
• Online Access: http://www.sciencedirect.com/science/article/pii/S187853521100311X

8-Hydroxyquinoline, HQ, or poly(8-hydroxyquinoline), PHQ, was immobilized on the activated silica gel for extractive concentration of metal ions. FTIR was used to prove the result caused by the immobilization of PHQ on the surface of functionalized silica gel. The thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) prove that Si–PHQ–Cu is more highly thermally stable and strongly adsorbed water than Si–PHQ. Spectra of the solution produced from substrate of PHQ immobilized on silica gel showed record peak at 305 nm was which was maximized at pH 7.2 ± 0.1 of the universal buffer solution. By the addition of Cu(II) ion solution, a peak at 380 nm was appeared corresponding to formation of HQ–Cu(II) coordinated complex. Spectra of 100 mg of substrate (Si–HQ, Si–PHQ, or Si–Cu) at pH 7.2 ± 0.1 universal buffer solution was recorded, solutions of metal ions were added, after contact time, filtrate, dissolve the solid precipitate in pure ethanol and record the spectra of this solution. A peak at 380 nm appeared corresponding to HQ–Cu(II) complex. The capacity of Si–HQ for extraction of Cu(II) ion was 10 mmol/g. Immobilization of Cu(II) metal ion on silica gel (Si–Cu) was studied. The maximum amount of HQ that can be extracted was 7 mmol/g. In the case of Fe(III) ion on Si–HQ, new two peaks appeared at 580 and 455 nm. The capacity of Si–HQ for extraction of Fe(III) ion was 20 mmol/g. Addition of Cu(II) on Si–PHQ, a new peak at 380 nm was appeared corresponding to PHQ–Cu(II) coordinated complex. The capacity of Si–PHQ for extraction of Cu(II) ion was 40 mmol/g. While, Si–Cu can extract PHQ, the maximum amount of PHQ that can be extracted was 20 mmol/g. Spectra of Fe(III) ion on Si–PHQ was recorded, new two peaks were appeared at 580 and 455 nm corresponding to the formation of PHQ–Fe(III). The capacity of Si–PHQ for extraction of Fe(III) ion was 40 mmol/g. PHQ immobilized on silica gel was useful for removal of Iron from the sytron syrup (anti-anemic).