A new guar gum-based adsorbent for the removal of Hg(II) from its aqueous solutions.
Modification of biopolymers by oxidation is an easy process to develop effective adsorbents for the removal of toxic metal ions from their aqueous solutions. In the present study, guar gum (GG) was crosslinked with epichlorohydrin and then oxidized to the polydialdehyde form (GG-clPDA). The latter was converted to a Schiff-base, GG-clCHN(CH2)6NCHGG, by reaction with hexamethylenediamine. Different forms of the modified GG were characterized by SEM, FTIR and XRD and investigated as adsorbents for the removal of Hg(II) ions from their aqueous solutions. The adsorption process was carried out through the variation of time, temperature, pH and initial concentration of Hg(II) ions. GG-clCHN(CH2)6NCHGG was observed to be an efficient adsorbent with a maximum adsorption capacity of 41.13 mg/g. It is reusable up to five cycles at the optimum conditions obtained for the maximum ions uptake. The kinetic data generated fit the Freundlich isotherm and pseudo-second order kinetics.
Himachal Pradesh University, Department of Chemistry, Shimla 171005, India.
Shiwali
S
Thakur
Himachal Pradesh University, Department of Chemistry, Shimla 171005, India.
Sapana
S
Kumari
Himachal Pradesh University, Department of Chemistry, Shimla 171005, India.
Priyanka
P
Dogra
Himachal Pradesh University, Department of Chemistry, Shimla 171005, India. Electronic address: ghanshyam_in2000@yahoo.com.
Ghanshyam S
GS
Chauhan
D000327:Adsorption; D003432:Cross-Linking Reagents / Q000737:chemistry; D003959:Diamines / Q000737:chemistry; D004811:Epichlorohydrin / Q000737:chemistry; D005685:Galactans / Q000737:chemistry*; D000075322:Heavy Metal Poisoning; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008351:Mannans / Q000737:chemistry*; D017669:Mercury Compounds / Q000302:isolation & purification*; D053149:Plant Gums / Q000737:chemistry*; D011041:Poisoning / Q000517:prevention & control; D012545:Schiff Bases / Q000138:chemical synthesis*; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D003432:Cross-Linking Reagents; D003959:Diamines; D005685:Galactans; D008351:Mannans; D017669:Mercury Compounds; D053149:Plant Gums; D012545:Schiff Bases; D014874:Water Pollutants, Chemical; D004811:Epichlorohydrin; C007894:guar gum; C007297:1,6-diaminohexane
Freundlich isotherm; Guar gum; Hexamethylenediamine; Pseudo-second order kinetics; Schiff-base