Investigation of the Changes in Surface Area and FT-IR Spectra of Activated Carbons Obtained from Hazelnut Shells by Physicochemical Treatment Methods

Abstract

In this study, raw hazelnut shells were used to obtain charcoal by pyrolysis at 250°C. The obtained material was subjected to physical, chemical, and physicochemical treatment methods to obtain activated carbons (ACs). Effect of the treatment procedures was determined by measuring the surface area of the produced ACs. In addition, changes in the functional groups of the obtained ACs during these treatments were determined with the Fourier transform infrared spectroscopy (FT-IR). To determine the most effective chemical agent, the charcoal samples were examined for Pb(II) adsorption from aqueous solutions under different pH conditions of 4 to 6. According to the results, the most effective chemical agent was determined as Ca(OCl)2. Effect of microwave and ultrasound treatments was also examined during Pb(II) adsorption by the chemically treated AC. The results showed that chemical treatment with Ca(OCl)2, microwave treatment for 5 minutes, ultrasound treatment for 20 minutes, and pyrolysis at 700°C together were the most suitable combination enhancing the surface area of the adsorbent. This combination increased the surface area and the adsorption capacity of the adsorbent by 202 and 4.76 times, respectively, when compared to those of the raw hazelnut shell.

Methylene Blue Removal Using Coconut Shell Biochar Synthesized Through Microwave-Assisted Pyrolysis

“…Hence, to increase its capacity as adsorbent, it is beneficial to conduct the activation process using chemical such as sodium carbonate [45]. Besides, the post physical treatment such as ultrasound treatment [46] and pulverization is also beneficial since it help to create new external surface area [42].…”

KARAKTERISASI NANOPARTIKEL KARBON AKTIF DARI DAUN ECENG GONDOK (Eichhornia crassipes) BERDASARKAN VARIASI SUHU DAN WAKTU AKTIVASI

“…Berdasarkan spektra pada Gambar 1 dan 2, puncak serapan gugus pada karbon aktif standard (komersial) terdeteksi pada bilangan gelombang 3510,45; 2931,80; 2291,43; 1635,64; dan 1126,43 cm -1 yang berturut-turut merupakan vibrasi O-H (Sencan and Kilic, 2015); ikatan C-H; ikatan C≡C (Tran et al, 2017); peregangan ikatan C=C (Mistry 2009); dan peregangan gugus C-O (Pehlivan, 2017).…”

Effectiveness of Raw versus Activated Coconut Shells for Removing Arsenic and Mercury from Water

“…It is also not surprising that the activated charcoal did not markedly outperform the raw (chemically-unmodified) coconut powder form in removing the toxic metals from water. Pyrolysis of carbon materials during activated charcoal formation causes loss of the cellulose, hemicellulose and lignin present on the biomaterial, and the introduction of acidic/polar oxygen functional groups (Sencan & Kilic, 2015), which become the "new" sites for adsorbing or removing contaminants. Various oxidizing post treatments are carried out to stimulate new functional groups that can adsorb a variety of contaminants (Sencan & Kilic, 2015).…”

“…Pyrolysis of carbon materials during activated charcoal formation causes loss of the cellulose, hemicellulose and lignin present on the biomaterial, and the introduction of acidic/polar oxygen functional groups (Sencan & Kilic, 2015), which become the "new" sites for adsorbing or removing contaminants. Various oxidizing post treatments are carried out to stimulate new functional groups that can adsorb a variety of contaminants (Sencan & Kilic, 2015). The use of chemicals such as CaCl 2 during the chemical activation process, renders the surface of the activated charcoal to contain more porous structures, and net large surface area to facililate the adsorption of contaminants (Girgis & El-Hendawy, 2002;Yin et al, 2007).…”