Binary Adsorption of Copper(II) and Cadmium(II) from Aqueous Solutions by Biomass of Marine Alga<i>Durvillaea potatorum</i>

Several aquatic environments have been contaminated with heavy metals dumped via industrial effluents. Numerous studies have been published regarding the removal of single metals from aqueous solutions by microalgal biomass. However, such studies do not reflect the actual problem associated with industrial effluents because usually more than one metal species is present. Here we studied the biosorption capacity of Zn 2? and Cd 2? as single-and binarymetal systems by two microalgae, Scenedesmus obliquus and Desmodesmus pleiomorphus, isolated from a polluted site in Northern Portugal. For each metal independently, D. pleiomorphus showed a higher metal sorption capacity than S. obliquus, at concentrations ranging from 60 to 300 mg/l (except 150 mg Cd /l). Maximum amounts of Zn 2? and Cd 2? removed were 22.3 and 60.8 mg/g by S. obliquus, and 83.1 and 58.6 mg/g by D. pleiomorphus. In binary-metal solutions, S. obliquus was in general able to remove Zn 2? to higher extents than Cd 2? , whereas the opposite was observed with D. pleiomorphus. The simultaneous uptake of Zn 2? and Cd 2? by both microalgae was considerably lower than that of their single-metal counterparts, at equivalent concentrations. Although microalgal uptake from binary-metal solutions was lower than from single-metal ones, the wild microalgae selected were able to efficiently take up mixtures of Zn 2? and Cd 2? up to 300 mg/l of both metals-thus materializing a promising bioremediation vector for polluted waters.

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“…Those observations are consistent with other studies: Yu and Kaewsarn (1999) and Mallick (2003) described a lower uptake of Cu 2? -Cd 2?…”

Section: Resultssupporting

confidence: 94%

Capacity of simultaneous removal of zinc and cadmium from contaminated media, by two microalgae isolated from a polluted site

2011

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“…Chemical oxidation, reduction, precipitation, solidification, electrolytic recovery and ion exchange are some of the physicochemical waste water treatment processes which are being used for metal removal. Application of such methods however, is sometimes restricted because of technical or economical constraints (Bossrez et al 1997;Yu and Kaewsarn, 1999). Hence, more economical means such as biosorption for the removal of metals have been sought for.…”

mentioning

confidence: 99%

Equilibrium sorption isotherm studies of Cd(II), Pb(II) and Zn(II) ions detoxification from waste water using unmodified and EDTA-modified maize husk

Igwe¹,

Abia²

2007

Electron. J. Biotechnol.

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The mobilization of heavy metals in the environment due to industrial activities is of serious concern due to the toxicity of these metals in humans and other forms of life. The equilibrium adsorption isotherms of Cd(II), Pb(II) and Zn(II) ions, detoxification from waste water using unmodified and EDTA-modified maize husk have been studied. Maize husk was found to be an excellent adsorbent for the removal of these metal ions. The amount of these metal ions adsorbed increased as the initial concentration increased. Also, EDTAmodification enhanced the adsorption capacity of maize husk due to the chelating ability of ethylenediamine tetra acetic acid (EDTA). Among the three adsorption isotherms tested, Dubinin-Radushkevich isotherm gave the best fit with R 2 value ranging from 0.7646 to 0.9988 and an average value of 0.9321. This is followed by Freundlich and then Langmiur isotherms. The sorption process was found to be mostly a physiosorption process as seen from the apparent energy of adsorption which ranged from 1.03 KJ/mol to 12.91 KJ/mol. Therefore, this study demonstrates that maize husk which is an environmental pollutant could be used to adsorb heavy metals and achieve environmental cleanliness.

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“…In particular, the non-competitive Langmuir and Freundlich isotherms have been useful tools for the description and comparison of heavy metal sorption by different sorbents (Chong and Volesky, 1996;Yu and Kaewsarn, 1999;Mahvi et al, 2007;Asgari et al, 2008;Mahvi, 2008). These isotherms relate metal uptake per unit weight of adsorbent, q, to the equilibrium adsorbate concentration in the bulk fluid phase, C e .…”

Section: Resultsmentioning

confidence: 99%

Removal of chromium (VI) from aqueous solutions using Lewatit FO36 nano ion exchange resin

Rafati

Mahvi

Asgari

et al. 2009

Int. J. Environ. Sci. Technol.

148

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ABSTRACT:The removal of the chromium (VI) ion from aqueous solutions with the Lewatit FO36 ion-exchange resin is described at different conditions. The effects of adsorbent dose, initial metal concentration, contact time and pH on the removal of chromium (VI) were investigated. The batch ion exchange process was relatively fast and it reached equilibrium after about 90 min of contact. The ion exchange process, which is pH dependent showed maximum removal of chromium (VI) in the pH range 5.0-8.0 for an initial chromium (VI) concentration of 0.5 mg/dm 3 . The equilibrium related to Lewatit FO36 ion-exchange capacity and the amounts of the ion exchange were obtained using the plots of the Langmuir adsorption isotherm. It was observed that the maximum ion exchange capacity of 0.29 mmol of chromium (VI)/g for Lewatit FO36 was achieved at optimum pH value of 6.0. The ion exchange of chromium (VI) on this cationexchange resin followed first-order reversible kinetics.

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Binary Adsorption of Copper(II) and Cadmium(II) from Aqueous Solutions by Biomass of Marine AlgaDurvillaea potatorum

Cited by 61 publications

References 24 publications

Capacity of simultaneous removal of zinc and cadmium from contaminated media, by two microalgae isolated from a polluted site

Capacity of simultaneous removal of zinc and cadmium from contaminated media, by two microalgae isolated from a polluted site

Equilibrium sorption isotherm studies of Cd(II), Pb(II) and Zn(II) ions detoxification from waste water using unmodified and EDTA-modified maize husk

Removal of chromium (VI) from aqueous solutions using Lewatit FO36 nano ion exchange resin

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