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    Adsorption of heavy metal ions onto ethylene diamine-derived and Cibacron Blue F3GA-incorporated microporous poly(2-hydroxyethyl methacrylate) membranes
    (Elsevier Science Bv, 2000) Denizli, A; Say, R; Patir, S; Arica, MY
    Microporous poly( 2-hydroxyethylmethacrylate) (PHEMA) membranes carrying ethylene diamine (EDA) and Cibacron Blue F3GA were prepared for the removal of heavy metal ions (i.e. mercury, copper, lead and cadmium) from aqueous solutions containing different amounts of these ions (5-700 mu g 1(-1)) and at different pH values (2.0-8.0). The non-specific adsorption of heavy metal ions on the underived membranes was very low (3.3 mmol/m(2) for Hg(II), 0.5 mmol/m(2) for Cu(II), 1.2 mmol/m(2) for Pb(II) and 1.1 mmol/m(2) for Cd(II)). Cibacron Blue F3GA attachment significantly increased the heavy metal adsorption (16.3 mmol/m(2) for Hg(II), 19.9 mmol/m(2) for Cu(II), 23.4 mmol/m(2) for Pb(II) and 38.4 mmol/m(2) for Cd(LI)). When the heavy metal ions competed (in the case of the adsorption from a mixture) the adsorption capacities were 7.1 mmol/m(2) for Hg(II), 17.9 mmol/m(2) for Cu(II), 6.2 mmol/m(2) for Pb(II) and 9.1 mmol/m(2) for Cd(lI). The observed order in adsorption was found to be Cd(II) > Pb(II) > Cu(II) > Hg(II) for non-competitive conditions. The adsorption of heavy metal ions increased with increasing pH and reached a plateau value at around pH 5.0. Desorption of heavy metal ions was achieved using 0.1 M HNO3. These membranes are suitable for repeated use for more than five cycles without considerable loss of adsorption capacity. (C) 2000 Elsevier Science B.V. All rights reserved.
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    Biosorption of inorganic mercury and alkylmercury species on to Phanerochaete chrysosporium mycelium
    (Elsevier Sci Ltd, 1999) Saglam, N; Say, R; Denizli, A; Patir, S; Arica, MY
    The biosorption of inorganic mercury (HgCl2), methyl mercury (CH3HgCl) and ethyl mercury (C2H5HgCl) onto the dry biomass of Phanerochaete chryosponum was studied from aqueous media which concentrations in the range of 5-500 mg l(-1). The surface charge density varied with pH, and the concentration of mercury species adsorbed significantly increased from pH 3.0 to maximum levels at pH 8.0. The biosorption of mercury ions by Phanerochaete chrysosporium increased as the initial concentration of Hg(II) ion increased in the adsorption medium. A biosorption equilibrium were established after about 6 h, the adsorbed Hg(II) ion did not significantly change further with time. The dissociation constant (k(d)) values were 72, 63, and 61 mg l(-1) for CH3HgCl, C2H5HgCl and for Hg(II), respectively. The maximum biosorption capacity (q(m)) at pH 7.0 was 79 mg for CH3HgCI, 67 mg for C2H5HgCl and 61 mg for Hg(II) per g of dried fungal biomass. The affinity order of mercury species was CH3HgCl > C2H5HgCl > and Hg(II). (C) 1999 Elsevier Science Ltd. All rights reserved.
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    Dye affinity poly(2-hydroxyethyl methacrylate) membranes for removal of heavy metal ions
    (Marcel Dekker Inc, 2000) Denizli, A; Say, R; Arica, MY
    The dichlorotriazinyl dye-ligand Procion Red HE-3B-anchored poly(EGDMA-HEMA) membranes were used for removal of heavy metal ions (i.e., copper, arsenic, cadmium and mercury) from aqueous media containing different amounts of these ions (0.1-4.5 mmol/L) and at different pH values (2.0-8.0). The HE-3B-anchored membranes from their single solutions were 6.4 mmol/m(2) for Cu(II), 30.1 mmol/m(2) for As(III), 76.3 mmol/m(2) for Cd(II) and 130.3 mmol/m(2) for Hg(II). When the heavy metal ions competed tin the case of the adsorption from their mixture) the adsorption capacities were 7.8 mmol/m(2) fur Cu(II), 24.5 mmol/m(2) for As(III), 27.6 mmol/m(2) for Cd(II) and 42.3 mmol/m2 for Hg(II). The same affinity order was observed under non-competitive and competitive adsorption which was as follows: Hg(II) > Cd(II) > As(III) > Cu(IT). The adsorption of heavy metal ions increased with increasing pH and reached a plateau value at around pH 5.0. Heavy metal ion adsorption from artificial wastewater was also studied. The adsorption capacities are 4.1 mmol/m(2) for Cu(II), 12.5 mmol/m(2) for As(III), 16.7 mmol/m(2) for Cd(II) and 21.3 mmol/m(2) for Hg(II). Desorption of heavy metal ions was achieved using 0.1 M HNO3. The Procion Red HE-3B-anchored membranes are suitable for repeated use for more than 5 cycles without noticeable loss of capacity.
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    Procion blue MX-3G-attached microporous poly(2-hydroxyethyl methacrylate) membranes for copper, arsenic, cadmium, and mercury adsorption
    (Marcel Dekker Inc, 1999) Denizli, A; Say, R; Testereci, HN; Arica, MY
    pHEMA membranes carrying 25.6 mmol Procion Blue MX-3G/m(2) were used for removal of heavy metal ions (i.e., copper, arsenic, cadmium, and mercury) from aqueous media containing different amounts of these ions (0.1-4.5 mmol/L) and at different pH values (2.0-8.0). The maximum adsorption capacities of heavy metal ions onto Procion Blue MX-3G-attached membranes under noncompetitive conditions were 5.6 mmol/m(2) for Cu(II), 19.6 mmol/m(2) for As(III), 46.2 mmol/m(2) for Cd(II), and 119.6 mmol/m(2) for Hg(II). The competitive adsorption capacities of the heavy metal ions were 6.9 mmol/m(2) for Cu(II), 21.2 mmol/m(2) for As(III), 33.9 mmol/m(2) for Cd(II), and 52.5 mmol/m(2) for Hg(II). The same affinity order was observed under noncompetitive and competitive adsorption: Hg(II) > Cd(IT) > As(III) > Cu(II). The adsorption of heavy metal ions increased with increasing pH and reached a plateau value at around pH 6.0. Adsorption of heavy metal ions from artificial wastewater was also studied. The adsorption capacities are 3.5 mmol/m(2) for Cu(I), 10.2 mmol/m(2) for As(III), 24.7 mmol/m(2) for Cd(II), and 37.3 mmol/m(2) for Hg(II). Desorption of heavy metal ions was performed using 0.1 M HNO3. Procion Blue MX-3G-attached membranes are suitable for repeated use of more than 5 cycles without noticeable loss of capacity.
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    Removal of heavy metal ions from aquatic solutions by membrane chromatography
    (Elsevier Science Bv, 2000) Denizli, A; Say, R; Arica, Y
    Polyvinylalcohol membranes were prepared by a solvent casting technique. Metal-complexation ligand, i.e. monochlorotriazinyl-dye Cibacron Blue F3GA was then attached. These membranes with a high water content of 119%, and containing 8.7 mmol Cibacron Blue F3GA/m(2) were used in the adsorption/stripping of some selected heavy metal ions [Cu(II), Hg(II), Pb(II) and Cd(II)] from aquatic solutions containing varying initial concentration of metal ions. Adsorption rates were very high, and equilibrium was achieved in about 10 min. The non-specific adsorption of heavy metal ions on the plain membranes was low [0.63 mmol/m(2) for Cu(II), 0.75 mmol/m(2) for Hg(II), 0.94 mmol/m(2) for Pb(II) and 1.22 mmol/m(2) for Cd(II)]. The maximum adsorptions of heavy metal ions onto the Cibacron Blue F3GA-attached affinity membranes for non-competitive conditions were 16.9 mmol/m(2) for Hg(II), 19.2 mmol/m(2) for Cu(II), 25.8 mmol/m(2) for Pb(II), 32.4 mmol/m(2) for Cd(II). The observed order in adsorption was found to be Cd(II) > Pb(II) > Cu(II) > Hg(II). Different behavior was observed for competitive adsorption. The order of affinity was Cu(II) > Cd(II) > Hg(II) > Pb(II). Regeneration of polyvinylalcohol membranes was done by using 0.1 M HNO3 in 30 min. Heavy metal ions could be repeatedly adsorbed and stripped without significant decrease in adsorption capacity. The experimental data of adsorption from solutions containing metal ions were found to correlate well with Langmuir isotherm equation. (C) 2000 Elsevier Science B.V. All rights reserved.
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    Synthesis and adsorption properties of poly(2-hydroxyethylmethacrylate-co-methacrylamidophenylalanine) membranes for copper ions
    (Elsevier Science Bv, 2000) Denizli, A; Say, R; Patir, S; Arica, Y
    In the first step of this study, the metal complexing ligand, 2-methacrylamidophenylalanine (MAPA), was synthesized by using methacrylochloride and phenylalanine. The MAPA monomer was characterized by NMR. Then, poly(2-hydroxyethylmethacrylate -co-2-methacrylamidophenylalanine) [p(HEMA-co-MAPA)] membranes were prepared by UV-initiated photo-polymerization of HEMA and MAPA in the presence of an initiator (azobisisobutyronitrile? AIBN). p(HEMA-co-MAPA) membranes were characterized by FTIR and elemental analysis. These p(HEMA-co-MAPA) affinity membranes with a swelling ratio of 133.2%, and containing 18.9 mmol MAPA/m(2), were used in the adsorprion-desorption of copper(II) ions from synthetic solutions. Adsorption equilibria was reached in about 2 h. The maximum adsorption of Cu(II) ions onto pHEMA was about 0.54 mmol Cu(II)/m(2). The MAPA incorporation significantly increased the Cu(II) adsorption capacity by chelate formation of Cu(II) ions with MAPA molecules (23.8 mmol Cu(II)/m(2)), which was observed at pH 7.0. The chelating membrane can be easily regenerated by 0.1 M HNO3 with higher effectiveness. (C) 2000 Elsevier Science B.V. All rights reserved.