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    Öğe
    Adsorption of copper (II) from aqueous solutions using adsorbent obtained with sodium hydroxide activation of biochar prepared by microwave pyrolysis
    (Springer Heidelberg, 2024) Tegin, Ibrahim; Oc, Sema; Saka, Cafer
    Microwave heating is one of the leading methods that save energy, time, and cost for the conversion of bio-waste into biochar in the agricultural sector. In this study, in the first stage, economical biochar production from pistachio green hulls by microwave heating method is in question. In the second step, sodium hydroxide(NaOH) activation was followed to improve the surface properties of biochar. This adsorbent obtained was applied to remove copper ions(Cu(II)) from wastewater. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), thermogravimetry differential thermal analysis (TG/DTG), and nitrogen adsorption/desorption methods were used to characterize the biochar samples. In adsorption studies, kinetic, isotherm, and thermodynamic parameters were investigated. Cu(II) adsorption capacity on modified biochar obtained by Langmuir isotherm was found to be 227.27 mg/g. In addition, the mechanism of Cu(II) adsorption on modified biochar has been proposed. Biochar, which is obtained from the green shells of pistachios, which is widely available and grown in Turkey, by microwave method and then NaOH activation, is a potential solution for both the improvement of water pollution caused by heavy metals and the disposal of related wastes with an appropriate method.
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    Öğe
    Facile modification strategies on hydrochar-based carbon particles with hydrothermal carbonization from green pistachio hulls for the removal of cadmium ions from aqueous solutions
    (Springer Heidelberg, 2023) Oc, Sema; Tegin, Ibrahim; Yabalak, Erdal; Saka, Cafer
    The aim of this study is based on the efficient removal of cadmium ions (Cd2+) from aqueous solutions with the adsorbent obtained by various modification strategies on hydrochar-based carbon particles obtained by hydrothermal carbonization from green pistachio hulls as a precursor. Hydrochloric acid (HCl), sodium hydroxide (NaOH), or phosphoric acid (H3PO4) were used to functionalize the surface to increase the adsorption capacity of hydrochar. Maximum Cd2+ adsorption capacity from environmental waters by PHHC-NaOH hydrochar at 298 K was found to be 526.31 mg/g. Surface morphology and chemical compositions of hydrochar were investigated by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive spectroscopy (EDS), and thermogravimetric/differential (TG-DTA) and nitrogen adsorption/desorption analyses. Isotherm, kinetic, and thermodynamic properties were evaluated in detail. Also, possible mechanisms for Cd2+ binding on modified hydrochar were evaluated.
  • [ X ]
    Öğe
    Facile phosphorus and oxygen heteroatom functionalization of biochar based on biomass prepared by microwave pyrolysis for adsorption process of cadmium in aqueous solution
    (Springer Heidelberg, 2024) Tegin, Ibrahim; Oc, Sema; Saka, Cafer
    In this study, in the first stage, biochar is produced from green pistachio hulls (PGHMAC) by microwave heating method, which saves energy, time and cost. In the second step, with the activation of phosphoric acid (H3PO4), the surface properties of the biochar were modified by phosphorus (P) and oxygen (O) doping (O- and P-doped PGHMAC). This adsorbent obtained was applied to remove cadmium (Cd(II)) from wastewater. FTIR, SEM, EDX, and ICP-OES analyses were used for the characterization of the samples. FTIR, EDX, and ICP-OES analysis results showed the presence of oxygen and phosphorus groups on the surface of the relevant adsorbent. The contents of C and O atoms for P- and O-doped PGHMAC were found to be 62.54% and 36.12%, respectively. Also, about 1.29% of P atoms were found with H3PO4 activation. The kinetic, isotherm, and thermodynamic parameters of the adsorption studies were investigated. Maximum Cd(II) adsorption capacities of P- and O-doped PGHMAC at 298 K, 308 K, and 318 K temperatures were calculated as 78.74, 109.89, and 133.33 mg/g by Langmuir model, respectively. The mechanism of Cd(II) adsorption on O- and P-doped PGHMAC has been proposed.