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Title: Metal binding stoichiometry and isotherm choice in biosorption

Abstract

Seaweeds that possess a high metal binding capacity may be used as biosorbents for the removal of toxic heavy metals from wastewater. The binding of Cu and Ni by three brown algae (Sargassum, Colpomenia, Petalonia) and one green alga (Ulva) was investigated at pH 4.0 and pH 3.0. The greater binding strength of Cu is reflected in a binding constant that is about 10 times as high as that of Ni. The extent of metal binding followed the order Petalonia {approximately} Sargassum > Colpomenia > Ulva. This was caused by a decreasing number of binding sites and by much lower metal binding constants for Ulva as compared to the brown algae. Three different stoichiometric assumptions are compared for describing the metal binding, which assume either that each metal ion M binds to one binding site B forming a BM complex or that a divalent metal ion M binds to two monovalent sites B forming BM{sub 0.5} or B{sub 2}M complexes, respectively. Stoichiometry plots are proposed as tools to discern the relevant binding stoichiometry. The pH effect in metal binding and the change in proton binding were well predicted for the B{sub 2}M or BM{sub 0.5} stoichiometries with the former beingmore » better for Cu and the latter preferable for Ni. Overall, the BM{sub 0.5} model is recommended because it avoids iterations.« less

Authors:
;
Publication Date:
Research Org.:
Hong Kong Baptist Univ. (HK)
OSTI Identifier:
20000709
Resource Type:
Journal Article
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 33; Journal Issue: 21; Other Information: PBD: 1 Nov 1999; Journal ID: ISSN 0013-936X
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; INDUSTRIAL WASTES; WASTE WATER; WASTE PROCESSING; COPPER; NICKEL; SEAWEEDS; SORPTIVE PROPERTIES; ADSORBENTS; STOICHIOMETRY; ADSORPTION ISOTHERMS

Citation Formats

Schiewer, S, and Wong, M H. Metal binding stoichiometry and isotherm choice in biosorption. United States: N. p., 1999. Web. doi:10.1021/es981288j.
Schiewer, S, & Wong, M H. Metal binding stoichiometry and isotherm choice in biosorption. United States. https://doi.org/10.1021/es981288j
Schiewer, S, and Wong, M H. 1999. "Metal binding stoichiometry and isotherm choice in biosorption". United States. https://doi.org/10.1021/es981288j.
@article{osti_20000709,
title = {Metal binding stoichiometry and isotherm choice in biosorption},
author = {Schiewer, S and Wong, M H},
abstractNote = {Seaweeds that possess a high metal binding capacity may be used as biosorbents for the removal of toxic heavy metals from wastewater. The binding of Cu and Ni by three brown algae (Sargassum, Colpomenia, Petalonia) and one green alga (Ulva) was investigated at pH 4.0 and pH 3.0. The greater binding strength of Cu is reflected in a binding constant that is about 10 times as high as that of Ni. The extent of metal binding followed the order Petalonia {approximately} Sargassum > Colpomenia > Ulva. This was caused by a decreasing number of binding sites and by much lower metal binding constants for Ulva as compared to the brown algae. Three different stoichiometric assumptions are compared for describing the metal binding, which assume either that each metal ion M binds to one binding site B forming a BM complex or that a divalent metal ion M binds to two monovalent sites B forming BM{sub 0.5} or B{sub 2}M complexes, respectively. Stoichiometry plots are proposed as tools to discern the relevant binding stoichiometry. The pH effect in metal binding and the change in proton binding were well predicted for the B{sub 2}M or BM{sub 0.5} stoichiometries with the former being better for Cu and the latter preferable for Ni. Overall, the BM{sub 0.5} model is recommended because it avoids iterations.},
doi = {10.1021/es981288j},
url = {https://www.osti.gov/biblio/20000709}, journal = {Environmental Science and Technology},
issn = {0013-936X},
number = 21,
volume = 33,
place = {United States},
year = {Mon Nov 01 00:00:00 EST 1999},
month = {Mon Nov 01 00:00:00 EST 1999}
}