Sürdürülebilir Kalkınma Amaçları
Yazarlar
Yayınlar
- MakaleYalnız künye2021Comparison of kinetics of Cr (III) ions removal from wastewater using raw and activated montmorillonite minerals
İrdemez, Şahset; Durmuş, Gül; Kul, Sinan; Torun, Fatma Ekmekyapar; Bingül, Züleyha
In this study, kinetics of the removal of Cr (III) from the waters by adsorption have been investigated using montmorillonite natural clay that was obtained from the vicinity of Narman, Erzurum in Turkey. Activation energy, thermodynamic values and adsorption kinetics were determined. In addition, the trials were repeated by subjecting to the same adsorbent activation process. The values found for these two adsorbents were compared. As a result of the experiments, the parameters affecting the adsorption kinetics were examined. It was determined that the adsorption process could be best depicted by pseudo second order reaction kinetics. Using pseudo second order reaction rate constants, ΔH° =-25.791 kJ mol-1 and ΔS° = 106.19 joule mol-1 were calculated for raw adsorbent. For the activated adsorbent, ΔH° =-18,806 kJ mol-1 and ΔS° = 79.37 joule mol-1 were calculated. That ΔG° increases as temperature increases indicates; adsorption is more spontaneous at high temperatures. Negative ΔH° values show that the reaction is exothermic. The positive values of ΔS° indicate increased randomness at the adsorbent/solution interface during the adsorption of chrome.
AtıfScopus2WoS1OpenAlex3
İncele - MakaleYalnız künye2020Scopus SJRQ1Azo dye-functionalized magnetic Fe3O4/polyacrylic acid nanoadsorbent for removal of lead (II) ions
Sadak, Omer; Hackney, Robert; Sundramoorthy, Ashok K.; Yilmaz, Galip; Gunasekaran, Sundaram
We report the fabrication of a nanoadsorbent for the removal of heavy metals. The nanoadsorbent is comprised of ferric oxide (Fe3O4) magnetic nanoparticles (MNPs) covalently conjugated with polyacrylic acid (PAA) and further functionalized with an azo dye (Congo red, CR) using carbodiimide. This Fe3O4 core and PAA-CR shell system (MNP/PAA-CR) exhibited binding affinity towards various cations (Pb2+, Fe2+, Fe3+, Cd2+, and Cu2+) at room temperature. Using MNP/PAA-CR we studied its heavy metal removal effectiveness and kinetics targeting Pb2+ under various reactions conditions including time and pH. The Pb2+ removal efficiency and adsorption capacity were maximal at pH 6.5 and 45 min of reaction time, and the Pb2+ adsorption kinetics better fit a pseudo second-order model than a first-order model. The adsorption of Pb2+ by MNP/PAA-CR was also investigated by the so-called Langmuir and Freundlich isotherms, and the Langmuir isotherm predicted a maximum absorption of 195.3 mg.g-1. Our results further indicated that MNP/PAA-CR is potentially reusable after desorption of the adsorbed metal with only small decline in adsorption ability over five consecutive cycles of regeneration.
AtıfScopus26OpenAlex17İncele - MakaleYayıncıda açık erişim2018Scopus SJRQ2Optimization of Adsorption Parameters for Ultra-Fine Calcite Using a Box-Behnken Experimental Design
Uçurum, Metin; Özdemir, Akln; Teke, Çaǧatay; Serencam, Hüseyin; Ipek, Mümtaz
Removal of heavy metals from wastewater is a significant issue because it prevents environmental-based concerns and impacts a large number of diseases and disorders. Many low-cost natural materials have been offered recently as possible precursors to commercial synthetic adsorbents. Ultra-fine calcite, one of these natural materials, has been investigated as a potential commercial adsorbent. Response surface designs are effective experimental techniques to investigate the heavy metal adsorption capacity of ultra-fine calcite. In the present study, one such response surface design, Box-Behnken, is used in order to optimize adsorption factors, such as pH level, initial metal concentration, stirring rate and adsorption time, and to determine the heavy metal capacity of this adsorbent. Our results show that the proposed methodology is an effective approach to optimizing the adsorption process and to maximize the heavy metal capacity.
AtıfScopus9WoS7OpenAlex12İncele