Fractionation of wheat straw meal after pretreatment with acidified zinc chloride solutions

Simkovic, I; Antal, Miroslav; Alföldi, Juraj

doi:10.1016/0144-8617(94)90034-5

Cited by 6 publications

(1 citation statement)

References 15 publications

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“…Lignin is not hydrolyzed by acid, but it can be made soluble by alkali treatment, while organosolv treatment mainly focuses on solubilization of carbohydrates, and ionic liquid can dissolve both carbohydrates and lignin. Zinc chloride (ZnCl 2 ) is highly effective swelling reagent for biomass, separates hemicellulose from biomass (Simkovic et al 1994), and is highly selective for hemicellulose hydrolysis (Cao et al 1995a). Zinc-cellulose complexes, formed due to reaction of zinc ions with carbohydrates, could be easily acid hydrolyzed.…”

Section: Introductionmentioning

confidence: 99%

Chemical treatment of teff straw by sodium hydroxide, phosphoric acid and zinc chloride: adsorptive removal of chromium

Wassie

Srivastava

2016

Int. J. Environ. Sci. Technol.

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In this study, teff (Eragrostis tef) straw has been chemically treated and tested as an adsorbent for Cr(VI) removal. Chemically treatment of teff straw was done by NaOH, H 3 PO 4 and ZnCl 2 solutions. Scanning electron micrograph and X-ray diffraction were used for anatomical characterization, whereas Fourier transform infrared spectroscopy was used for surface change characterization of adsorbents. Effects of different experimental parameters like pH (2-12), initial Cr(VI) concentration (100-900 mg/L), adsorbent dose (2.5-20 g/L), contact time (15-360 min) and temperature (288-318 K) were studied. Temperature increment was found to stimulate the adsorption process. Langmuir isotherm was found to give better representation over wide range of temperature for untreated, H 3 PO 4 -as well as ZnCl 2 -treated teff straw, and Freundlich isotherm best represented the isotherm data for NaOH-treated teff straw. Maximum Cr(VI) adsorption capacity of untreated, NaOH-, H 3 PO 4 -and ZnCl 2 -treated teff straw was found to be 86.1, 73.8, 89.3 and 88.9 mg/g, respectively. Respective values of average effective diffusion coefficient (D e ) were found to be 2.8 9 10 -13 , 2.59 9 10 -14 , 1.32 9 10 -13 and 1.14 9 10 -13 m 2 /s, respectively. The negative value of DG o for all the adsorbents indicates Cr(VI) spontaneous adsorption. Isosteric heat of adsorption (DH st,a ) was found to vary with surface coverage (h). DH st,a increased for untreated, H 3 PO 4 -and ZnCl 2 -treated teff straw, and decreased steadily with h for NaOH-treated teff straw.

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Section: Introductionmentioning

confidence: 99%