Fourier-Transform Infrared Analysis of the Dehydration Mechanism of Mg(OH)2 and Chemically Modified Mg(OH)2

2021 ◽  
Author(s):  
Ryo Kurosawa ◽  
Masato Takeuchi ◽  
Junichi Ryu
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Infrared Analysis ◽  
Chemically Modified ◽  
Dehydration Mechanism

scholarly journals Adsorption of hexavalent chromium by activated carbon obtained from a waste lignocellulosic material (Ziziphus jujuba cores): Kinetic, equilibrium, and thermodynamic study

2018 ◽  
Vol 36 (3-4) ◽  
pp. 1066-1099 ◽  
Author(s):  
Radia Labied ◽  
Oumessaad Benturki ◽  
Adh’ Ya Eddine Hamitouche ◽  
André Donnot
Keyword(s):  
Fourier Transform ◽  
Activated Carbon ◽  
Hexavalent Chromium ◽  
Chemical Activation ◽  
Fourier Transform Infrared ◽  
Infrared Analysis ◽  
Order Kinetic ◽  
Lignocellulosic Material ◽  
Ziziphus Jujuba ◽  
Key Functional Groups

In aqueous solutions, hexavalent chromium Cr(VI) was successfully removed by activated carbon “ Z. jujuba rubidium carbonate-activated carbon” obtained from waste lignocellulosic material ( Ziziphus jujuba cores). Rubidium carbonate was used to prepare Z. jujuba rubidium carbonate-activated carbon by chemical activation using a 1:1 w/w ratio. Our results indicate that the obtained surface area of the activated carbon was equal to 608.31 m2/g. The adsorption study of Cr(VI) was investigated under batch conditions at constant stirring speed (220 r/min). Factors such as pH (1–6), temperature (20–40°C), adsorbent concentration (0.5–3 g/l), and initial Cr(VI) concentration (50–500 mg/l) were all studied to attain the maximum removal efficiency. Prior to the adsorption process, the morphology, elementary composition, and loss mass of activated carbon were characterized using scanning electron microscopy, X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Fourier transform infrared analysis of the adsorbent demonstrated the presence of key functional groups associated with the adsorption phenomenon such as those of hydroxyl and aromatic groups. The obtained results showed that the optimal conditions for a maximum adsorption efficiency are 2 for pH, 1 g/l for activated carbon dosage and 100 mg/l for Cr(VI) concentration. The removal percentage increased from 27.2 to 62.08%. The kinetic sorption was described by a pseudo-second-order kinetic equation ( R2 ≈ 0.995). The Tóth ( R2 = 0.997) and Elovich models were best to explain the sorption phenomenon. Thermodynamic studies showed that the adsorption of Cr(VI) onto activated carbon was feasible, spontaneous, and endothermic at 20–40°C. This novel Z. jujuba rubidium carbonate-activated carbon derived from Z. jujuba core has been found to be effective for the removal of Cr(VI) and not harmful to the ecosystem.

Improvement of Hydrophobicity of Urea Modified Tapioca Starch Film with Lignin for Slow Release Fertilizer

2012 ◽  
Vol 626 ◽  
pp. 350-354 ◽  
Author(s):  
Sarwono Ariyanti ◽  
Zakaria Man ◽  
Mohammad Azmi Bustam
Keyword(s):  
Fourier Transform ◽  
Water Uptake ◽  
Slow Release ◽  
Fourier Transform Infrared ◽  
High Potential ◽  
Tapioca Starch ◽  
Chemically Modified ◽  
Slow Release Fertilizer ◽  
Urea Release ◽  
Modified Tapioca Starch

Tapioca starch was chemically modified with urea in the presence of borate as crosslinker and catalyst. Fourier transform infrared (FTIR) and viscosity were performed to measure qualitatively the reactivity of the mixture. To improve the hydrophobicity, 10% of lignin (10%L) was then added into the starch-urea-borate (SUB) system. The incorporation of lignin leads to lower water uptake film. It was found that lignin retards the urea release and the SUB10%L film is stable and stayed intact for one month after immersing in water which shows high potential as a biopolymer for slow release fertilizer.

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