Naoki Kano

By Naoki Kano

Part of the book: Biomass Now

By Naoki Kano

Part of the book: Biomass Production and Uses

By Naoki Kano

Adsorption of Cr(VI) from aqueous solution onto the nanomaterials prepared by modified chitosan was investigated in a batch system to evaluate the efficiency of biomass as an adsorbent. The crosslinking materials of chitosan & silicon dioxide and carboxymethyl chitosan & silicon dioxide were synthesized, respectively, as new adsorbent materials for the removal of Cr(VI) from aqueous solutions. The adsorption potential of Cr(VI) by the nanomaterials for desalination was investigated by varying experimental conditions such as pH, contact time and the dosage of the nanomaterials. Adsorption isotherms of Cr(VI) onto the membrane were studied with varying initial concentrations under optimum experiment conditions. The surface property of the membrane was characterized by SEM (scanning electron microscope) and Fourier transform infrared spectrometer (FT-IR). The concentrations of Cr(VI) in solution are determined by ICP-AES (inductively coupled plasma atomic emission spectrometry). The membrane of carboxymethyl chitosan & silicon dioxide exhibited higher adsorption capacity than the membrane of chitosan & silicon dioxide for Cr(VI). The adsorption sites and specific surface area may be increased by changing from chitosan to carboxymethyl chitosan. The maximum adsorption capacity was estimated as 80.7 mg·g−1 for Cr(VI) under the optimum conditions.

Part of the book: Chitin-Chitosan

By Naoki Kano and Shuang Zhang

Layered double hydroxides (LDHs) are lamellar ionic compounds containing a positively charged layer and exchangeable anions in the interlayer. In this study, LDHs intercalated with chelating agents were synthesized by anion exchange reaction. The materials synthesized in this work were characterized by chemical analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD) to confirm their properties. Adsorption experiments from aqueous solutions containing known amounts of some heavy metallic ions onto the adsorbent were explored in a batch system. The amount of metallic ions adsorbed by LDHs intercalated with EDTA and precursor LDHs were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and atomic absorption spectrometry (AAS). In order to examine the adsorption capacity of LDHs intercalated with chelating agents, the adsorption experiment was investigated under the optimum condition. The data were applied to Langmuir and Freundlich isotherm models. The pseudo-second-order kinetic model was more adequate to describe the kinetic in this case. LDHs intercalated with chelating agents synthesized in this work can be promising adsorbents for heavy metals. It is very significant information from the viewpoint of environmental protection.

Part of the book: Advanced Sorption Process Applications

By Naoki Kano, Zou Ming, David Eva Vanessa Anak and Muhammad Nabil Md Sari

The goal of this research is to make chitosan beads that have been treated with sodium dodecyl sulfate (SDS) to remove chromium (Cr) from an aqueous solution effectively. The successful synthesis of the SDS-chitosan was proven through characterization, which were carried out using by scanning electron microscopy–energy dispersive X–ray spectroscopy (SEM-EDS), Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The adsorption of Cr on the SDS material was investigated by varying experimental conditions such as pH, contact time and adsorbent dosage. The maximum adsorption capacity of SDS-chitosan for Cr(III) was estimated to be 3.42 mg·g−1 and 3.23 mg·g−1 for Cr(VI). Based on the results of adsorption kinetics and isothermal models, the adsorption process conform to the pseudo-second-order and Langmuir isotherm models. This indicates that the adsorption of Cr on SDS-chitosan is mainly dominated by chemical adsorption and monolayer reaction. In addition, according to thermodynamic analyses, the adsorption of Cr is an endothermic reaction. These results show that the new adsorbent has obvious application prospect for removing Cr.

Part of the book: Sorption