naa a22 4500 510749518 CHVBK 20180411083059.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11270-013-1684-0 doi (NATIONALLICENCE)springer-10.1007/s11270-013-1684-0 Remediation of Tributyltin Contaminated Seawater by Adsorption Using nFe3O4, Activated Carbon and nFe3O4/Activated Carbon Composite Material [Elektronische Daten] [Olushola Ayanda, Olalekan Fatoki, Folahan Adekola, Bhekumusa Ximba] The remediation of tributyltin (TBT) by adsorption onto nFe3O4, activated carbon and nFe3O4/activated carbon composite material as a function of adsorbent dose, contact time, pH, stirring speed, initial TBT concentration and temperature was studied. The effect of temperature on kinetics and equilibrium of TBT sorption on the precursors and the composite was thoroughly examined. The adsorption kinetics is well fitted using a pseudo-second-order kinetic model, and the adsorption isotherm data of nFe3O4, activated carbon could be described by the Freundlich isotherm model whereas nFe3O4/activated carbon composite could be described by the Freundlich and Dubinin-Radushkevich isotherm models. Thermodynamic parameters (i.e. change in the free energy (∆G°), the enthalpy (∆H°) and the entropy (∆S°)) were also evaluated. The overall adsorption process was endothermic and spontaneous in nature. The results obtained also showed that 99.9, 99.7 and 80.1% TBT were removed from contaminated natural seawater by nFe3O4/activated carbon composite, activated carbon and nFe3O4, respectively. Springer Science+Business Media Dordrecht, 2013 Tributyltin nationallicence Adsorption nationallicence Nano-iron (III) oxide nationallicence Activated carbon nationallicence Composite nationallicence GC-FPD nationallicence q e : Amount of TBT adsorbed at equilibrium per unit weight of the adsorbent (in milligrams per gram) nationallicence q t : Amount of TBT adsorbed at any time (in milligrams per gram) nationallicence k 1 : Pseudo-first-order rate constant/minute nationallicence k 2 : Rate constant of pseudo-second-order adsorption (in grams per milligram minute) nationallicence h o : Initial adsorption rate (in milligrams per gram per minute) nationallicence α E : Constant in the Elovich rate equation (in grams per square minute per milligram) nationallicence β : Constant in the Elovich rate equation (in grams minute per milligram) nationallicence k p : Rate coefficient for particle diffusion controlled process nationallicence k : Fractional power rate constant nationallicence c a : Amount of adsorbed TBT on the adsorbent (in milligrams per gram) nationallicence c e : Equilibrium concentration of TBT in the bulk solution (in milligrams per litre) nationallicence c o : Initial concentration of the TBT aqueous solution nationallicence R : Gas constant (in joules per mole kelvin) nationallicence k L : Langmuir isotherm constant nationallicence A max : Maximum monolayer TBT adsorption capacity (in milligrams per gram) nationallicence k F : Freundlich isotherm constant nationallicence n F : Exponent in the Freundlich isotherm nationallicence k T : Temkin isotherm constant nationallicence b T : Constant in the Temkin isotherm (in joules per mole) nationallicence n T : Constant in the Temkin isotherm, n T = RT/b T nationallicence k D-R : Dubinin-Radushkevich (D-R) isotherm constant nationallicence ε : Polanyi potential = RT ln(1 + 1/c e) nationallicence E : Mean free energy (in joules per mole), E = 1/√2k D-R nationallicence q m : Maximal substance amount of adsorbate per gram of the adsorbent nationallicence Δ G ° : Standard Gibbs free energy (in kilojoules per mole) nationallicence Δ H ° : Standard enthalpy change (in kilojoules per mole) nationallicence Δ S ° : Standard entropy change (in joules per kelvin per mole) nationallicence T : Absolute temperature nationallicence K c : Thermodynamic equilibrium constant nationallicence Ayanda Olushola Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa aut Fatoki Olalekan Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa aut Adekola Folahan Department of Chemistry, University of Ilorin, P.M.B 1515, Ilorin, Nigeria aut Ximba Bhekumusa Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa aut Water, Air, & Soil Pollution Springer Netherlands 224/9(2013-09-01), 1-13 0049-6979 224:9<1 2013 224 11270 https://doi.org/10.1007/s11270-013-1684-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-013-1684-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ayanda Olushola Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa aut NATIONALLICENCE 700 1- Fatoki Olalekan Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa aut NATIONALLICENCE 700 1- Adekola Folahan Department of Chemistry, University of Ilorin, P.M.B 1515, Ilorin, Nigeria aut NATIONALLICENCE 700 1- Ximba Bhekumusa Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, P.O. Box 1906, Bellville, South Africa aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/9(2013-09-01), 1-13 0049-6979 224:9<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer