Biosorption of Ni(II), Pb(II) and Zn(II) on calcium alginate beads: equilibrium, kinetic and mechanism studies

Abstract

The biosorption process of three divalent metal ions -nickel, lead and zinc-from on calcium alginate from aqueous solution was studied, in single component systems. The biosorbent were investigated by Fourier Transform Infrared Spectroscopy. The batch mode experiments of the adsorption process were carried out as a function of pH, initial metal ions concentration, sorbent dosage and contact time. The adsorption infl uencing parameters for the maximum removal of metal ions were optimized. The experimental data were analyzed using the Langmuir, Freundlich, Langmuir-Freundlich, Koble-Corrigan and Redlich-Peterson models. The kinetic data of biosorption process were evaluated using pseudo-fi rst and pseudo-second order equations. The Weber and Morris model was employed to interpret the metal ions diffusion in biosorption process.

Adsorption of Ni2+ and Cd2+ from Water by Calcium Alginate/Spent Coffee Grounds Composite Beads

“…The values of the current study were below the values for adsorption of Ni 2+ by alginate beads reported in the literature. The values for Cd 2+ range from 10.20 mg/g obtained by Mahmood, Z. et al [38] to 198.43 mg/g obtained by Papageorgiou, S.K. (Sips model) [15].…”

Analysis of the Degradation Process of Alginate-Based Hydrogels in Artificial Urine for Use as a Bioresorbable Material in the Treatment of Urethral Injuries

“…The absorbance in the range 3000 to 3500 cm −1 , characteristic for the stretching of hydroxyl bonds (O-H), was the highest for samples crosslinked with calcium ions. Tensile vibration bands of symmetrical and asymmetrical CO carboxyl bonds and divalent ions were observed at values ranging from 1400 to 1600 cm −1 , while bands from 1000 to 1200 cm −1 characteristic for C-O bond vibration, at 800 cm −1 characteristic for mannuronic acid, and at 700 cm −1 characteristic for guluronic acid were also observed upon binding crosslinking ions [32][33].…”

Hemp fibers (Cannabis sativa) impregnated by Ca-alginate gel as a novel biosorbent for the removal of Pb(II) and Zn(II) ions

“…Prvi linearni deo zavisnosti može se pripisati brzoj površinskoj adsorpciji, drugi -intračestičnoj difuziji, dok poslednji linearni deo zavisnosti pretstavlja finalni ravnotežni stupanj. S obzirom da su prikazane zavisnosti multi-linearne, i obzirom da ne prolaze kroz koordinatni početak, može se zaključiti da intračestična difuzija utiče na brzinu, ali nije jedini stupanj koji kontroliše brzinu adsorpcije [22,23,28]. Intračestična difuzija je nešto brža kod adsorpcije na modifikovanim vlaknima konoplje, usled lakše penetracije jona metala kroz fibrilisanu strukturu, mikropore i mikropukotine, do aktivnih mesta za adsorpciju.…”

“…Trake na 1602,7 i 1419,7 cm -1 , koje su posledica simetričnih i asimetričnih vibracija istezanja karboksilatnog anjona, COOH grupe, posle adsorpcije metalnih jona gotovo isčezavaju, što ukazuje da ove grupe gotovo u potpunosti učestvuju u jonskoj izmeni i kompleksaciji jona. Ovim se može podržati pretpostavka da je mali udeo alginata u kompozitu razlog manjeg sorpcionog kapaciteta kompozita u odnosu na čist alginat [17,28], jer je alginat nosilac karboksilnih grupa za koje se vezuju joni metala. U cilju poboljšanja efikasnosti ovog biosorbenta, potrebno je izvršiti optimizaciju količine alginata koji se koristi za impregnaciju vlakana konoplje.…”