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Friday, 17 March 2017

Production of cellulose nanocrystals from sugarcane bagasse fibers and pith

Published Date
Industrial Crops and Products
25 December 2016, Vol.93:4857, doi:10.1016/j.indcrop.2016.04.064

Nanocellulose: production, functionalisation and applications
  • Author 
  • Franciéli Borges de Oliveira a,,
  • Julien Bras c
  • Maria Teresa Borges Pimenta a
  • Antonio Aprigio da Silva Curvelo a,b
  • Mohamed Naceur Belgacem c
  • aLaboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Caixa Postal: 6192, 13083-970, Campinas, São Paulo, Brazil
  • bInstituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-carlense 400, São Carlos, 13566-590, Brazil
  • cÉcole Internationale du papier, de La communication imprimée et dês biomatériaux, 461 Rue de la Papeterie, CS10065, Saint Martin d'Hères Cedex, France

Highlights
  • Obtaining cellulose nanocrystals from agricultural residues.
  • Characterization of properties of cellulose nanocrystals obtained by acid hydrolysis of bleached/not bleached pulp.
  • Proposing new materials from agricultural waste.

Abstract

Cellulose nanocrystals (CNs) were produced from unbleached and bleached sugarcane bagasse pulps by classical H2SO4 hydrolysis of fiber and pith fractions of pressed culms. Both the raw materials and final products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, field emission gun scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The advantages and disadvantages of using both unbleached and bleached pulps for the production of CNs were demonstrated and discussed.
Graphical abstract

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  • ⁎ 
    Corresponding author.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/S0926669016302941

Removal of nitrate from aqueous solution by modified sugarcane bagasse biochar

Published Date
Ecological Engineering
October 2016, Vol.95:101111, doi:10.1016/j.ecoleng.2016.06.035
  • Author 
  •  Divband Hafshejani a,,
  • Abdolrahim Hooshmand a
  • Abd Ali Naseri a
  • Amir Soltani Mohammadi a
  • Fariborz Abbasi b
  • Amit Bhatnagar c,,
  • aDepartment of Irrigation and Drainage Engineering, Faculty of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Khuzestan, Iran
  • bAgricultural Engineering Research Institute (AERI), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
  • cDepartment of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland

Highlights

  • Nitrate adsorption was studied onto modified sugarcane bagasse biochar.
  • The biochar prepared at temperature of 300 °C had higher stable organic matter index.
  • The maximum adsorption capacity of modified biochar for nitrate was 28.21 mg g−1.
  • Solution pH was an important factor for nitrate adsorption by modified biochar.
Abstract

In the present study, chemically modified biochar (developed from sugarcane bagasse) was used for the nitrate removal from aqueous solution. The physico-chemical properties of modified biochar such as morphology, surface functional groups, elemental composition, cation exchange capacity, anion exchange capacity and surface area were analyzed. The effects of various operational parameters such as solution pH, adsorbent dosage, contact time, initial concentration of nitrate, co-existing anions and temperature were examined on nitrate adsorption by modified biochar. The experimental data were fitted to different adsorption kinetic models (pseudo-first-order, pseudo-second-order, intraparticle diffusion and Avrami models) and adsorption isotherms models (Langmuir, Freundlich, Sips and Dubinin–Raduskovich models). The obtained results showed that the maximum percentage of nitrate adsorption attained at equilibrium pH 4.64, after 60 min of contact time and with an adsorbent dose of 2 g L−1. In competing anions experiments, carbonate and chloride ions have shown maximum and minimum influence on the adsorption of nitrate by modified biochar sugarcane bagasse. Pseudo-second-order kinetic model and Langmuir isotherm model showed the best fit to the experimental adsorption data. The maximum adsorption capacity of modified biochar for nitrate removal was found to be 28.21 mg g−1. The values of ΔH°, ΔG° and ΔS° indicated that the nature of adsorption was endothermic, spontaneous and feasible.

Graphical abstract

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  • ⁎ 
    Corresponding authors.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/S0925857416303603

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