Selectivity of alginate gel for Cu vs Co

Jang, Larry K.; Nguyen, Duy V.; Geesey, Gill G.

doi:10.1016/0043-1354(94)e0090-s

Cited by 54 publications

(32 citation statements)

References 10 publications

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“…The observation of negative influence on the adsorption by the ionic strength is due to the competition in between Cu 2+ ions and Na + ions during the adsorption. This is consistent with the observations on other biosorbents such as an alginate gel [25] and protonated Sargassum [26]. …”

Section: Influence Of Ph and Ionic Strength On Sorption Equilibriumsupporting

confidence: 92%

Removal of copper by calcium alginate encapsulated magnetic sorbent

Lim

Zheng

Zou

et al. 2009

Chemical Engineering Journal

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Section: Influence Of Ph and Ionic Strength On Sorption Equilibriumsupporting

confidence: 92%

Removal of copper by calcium alginate encapsulated magnetic sorbent

Lim

Zheng

Zou

et al. 2009

Chemical Engineering Journal

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“…Struvite mineral growth can be enhanced by Proteus mirabilis ATCC 49565 CPS but not by other CPS (Dumanski et al 1994). The affinity and binding capacity for individual metal ions varies with CPS chemistry (McLean et al 1990a;McLean and Beveridge 1990;Jang et al 1995). Arecent study (Chen et al 1995) showed that Pb and Cd, bound to CPS, could be more readily transported through sandy aquifer material, since the CPS did not adhere to the sand.…”

Section: Extracellular Polymersmentioning

confidence: 95%

Microbial metal-binding mechanisms and their relation to nuclear waste disposal

McLean¹,

Fortin²,

Brown³

1996

Can. J. Microbiol.

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The cell surface polymers of microorganisms readily bind a variety of metal ions, which enables the organisms to immobilize potentially toxic metal ions before they encounter the plasma membrane. Under appropriate chemical conditions, bound metal ions can form a variety of minerals that may be of major geological importance. Many studies have shown the occurrence of metal binding and biomineralization in nature, but detailed knowledge of the underlying mechanisms is lacking. The microbial influence of this binding may be indirect, such as physicochemical influences on the solution chemistry, Eh, and pH; or direct, when it is determined by the type of organisms present, their energy metabolism, and the structural and chemical characteristics of the cell surface and extracellular polymers. Metal binding by bacterial cell surfaces has several implications in nuclear waste disposal including adsorption of soluble radionuclides. A detailed knowledge of the chemical mechanisms of metal interactions with the microbial cell surface will enhance our understanding of the geochemical environment within a nuclear waste disposal vault.Resume : Les polymkres de surface des microorganismes lient facilement une variktk d'ions mktalliques permettant ainsi B ces organismes d'immobiliser des ions mktalliques potentiellement toxiques avant qu'ils puissent atteindre la membrane plasmatique. Dans des conditions chimiques approprikes, ces ions mktalliques lies peuvent former une variktk de minCraux pouvant avoir une importance gkologique majeure. Plusieurs Ctudes ont dCjB dkmontrk que la liaison B des mCtaux et la biominkralisation se produisent dans la nature, mais on n'a pas une connaissance dktaillke des mkcanismes en cause. L'influence microbienne de cette liaison peut Ctre indirecte, comme des variations physicochimiques de la solution, Eh et pH, ou elle peut Ctre directe si elle est dkterminCe par le type de microorganismes prCsents, leur knergie mktabolique et les caractkristiques structurales et chimiques de la surface cellulaire et des polymkres extracellulaires. La liaison des mCtaux par la surface cellulaire bactkrienne a plusieurs implications pour I'Climination des dkchets nuclkaires, y compris l'adsorption des radionuclCides solubles. Une connaissance approfondie des mCcanismes chlmiques des interactions des mCtaux avec la surface des microorganismes va favoriser notre comprkhension de l'environnement geochimique i l'intkrieur d'une voute souterraine d'klimination des dkchets nuclCaires.

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“…17,18 An important application of alginate is to absorb heavy metals of Cu 2+ , Co 2+ , and Zn 2+ from aqueous media such as ore leachates and industrial waste. [19][20][21] Alginate gels will form with these cations in the solution and the Cu 2+ -binding efficiency of alginate is affected by the acidity of the solution. The coordinative structure of Cu-alginate gels was observed with NMR, 15 infrared (IR), electron spin resonance (ESR), and X-ray photoelectron spectroscopy (XPS).…”

mentioning

confidence: 99%

Sol–Gel Transition in Aqueous Alginate Solutions Induced by Cupric Cations Observed with Viscoelasticity

Liu

Qian

et al. 2003

Polym J

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ABSTRACT:Sol-Gel transition was occurred in 2 wt% aqueous solutions of four alginate samples with different molecular weight M w and the ratio M/G of repeat unit mannuronate (M) to guluronate (G) induced by adding cupric ions. The transition was monitored with dynamic moduli G and G in the linear region of viscoelasticity and the gel point was determined according to the Winter's criterion where the loss angle tan δ became independent of frequency ω. The mole ratio of Cu 2+ to the carboxyl group in alginate at gel point, f gel , was higher for the samples with lower molecular weight than those with higher molecular weight without obvious M/G dependence. This suggested there was no M/G selection of Cu 2+ complex formation with alginate. The relaxation critical exponent n for alginate samples with higher G content was lower than 0.5, meaning G > G for the critical gels with a denser network. The cupric ion number relevant to one alginate chain at the gel point, N gel , was estimated from f gel M n /M 0 and reflected the gel elasticity.KEY WORDS Alginate / Cupric Cations / Sol-Gel Transition / Critical Exponent / Dynamic Viscoelasticity / Alginate is a natural polysaccharide consisting of β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues (Figure 1) (1→4) linked in a nonregular blockwise pattern along the linear chain and is mainly used as a gelling agent in numerous food and pharmaceutical applications. [1][2][3][4] There are three types of dyad sequential blocks as MM, GG, and MG. These residue sequences endow with the alginate chain different stiffness, e.g., that the mean square end-to-end distance per uronate residue for G component is 2.2 times larger than that for the M component. 5 The chemical composition and sequence of the M and G residues depend on the biological source and growth and seasonal conditions. 1,2 The most attractive ability of alginate is the gel formation induced by adding various divalent cations, except Mg 2+ . 6 The gelation behavior and gel strength of aqueous alginate solutions strongly depend on the content of guluronate residues and also on the molecular weight and molecular weight distribution of alginates. [6][7][8] Matsumoto and Mashiko investigated the influence of added salts on the viscoelastic properties of aqueous alginate solution and argued that the interaction between alginate and metal cations did not work as the cross-linking point. 8 Matsumoto et al. also followed the gelation process in sodium alginate solutions induced by increasing polymer concentration without any divalent cations and found the promoting effect to the gelation of chain stiffness, i.e., the alginate with higher G residue content formed gel at lower concentration with more perfect structure. 9, 10 By viscometry, † To whom correspondence should be addressed.

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Selectivity of alginate gel for Cu vs Co

Cited by 54 publications

References 10 publications

Removal of copper by calcium alginate encapsulated magnetic sorbent

Removal of copper by calcium alginate encapsulated magnetic sorbent

Microbial metal-binding mechanisms and their relation to nuclear waste disposal

Sol–Gel Transition in Aqueous Alginate Solutions Induced by Cupric Cations Observed with Viscoelasticity

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