TY - JOUR
T1 - Hybrid Carbon Nanochromium Composites Prepared from Chrome-Tanned Leather Shavings for Dye Adsorption
AU - Arcibar-Orozco, Javier A.
AU - Barajas-Elias, Bertha S.
AU - Caballero-Briones, Felipe
AU - Nielsen, Lilja
AU - Rangel-Mendez, Jose R.
N1 - Publisher Copyright:
© 2019, Springer Nature Switzerland AG.
PY - 2019/7/1
Y1 - 2019/7/1
N2 - Every year, the leather tanning industry produces substantial quantities of residues such as chrome-tanned leather shavings (CTLS), which contain considerable amounts of Cr(III) salts. The residues have no particular value and under natural conditions can transform into toxic Cr(VI) wastes. The objective of the present work is to evaluate the transformation of these residues into carbon adsorbents at low temperatures (< 600 °C), using ZnCl2 as an activating agent. The pyrolysis temperature and residence times were studied. The materials were characterized and qualified by Acid Black 210 (AB) adsorption. The results indicated that low amounts of chromium oxides (less than 2% of Cr), in the form of 50–200 nm particles, remained after the synthesis procedure. The deposited chromium oxides were present in (II), (III), and (IV) oxidation states. The low preparation temperatures employed prevented further chromium oxidation to Cr(VI). Maximum surface areas of 439 m2/g were obtained. The materials efficiently removed AB (maximum experimental adsorption capacity of 44.4 mg/g) by means of electrostatic interaction caused by the positively charged distribution of the carbons. The adsorption capacity was not affected by temperature, but pH had a mixed effect due to the combination of a shift in surface charge distribution and dye speciation. The results demonstrated that it is possible to obtain a value-added product, i.e., carbons modified with chromium nanoparticles for dye removal, from a hazardous residue of the tanning industry.
AB - Every year, the leather tanning industry produces substantial quantities of residues such as chrome-tanned leather shavings (CTLS), which contain considerable amounts of Cr(III) salts. The residues have no particular value and under natural conditions can transform into toxic Cr(VI) wastes. The objective of the present work is to evaluate the transformation of these residues into carbon adsorbents at low temperatures (< 600 °C), using ZnCl2 as an activating agent. The pyrolysis temperature and residence times were studied. The materials were characterized and qualified by Acid Black 210 (AB) adsorption. The results indicated that low amounts of chromium oxides (less than 2% of Cr), in the form of 50–200 nm particles, remained after the synthesis procedure. The deposited chromium oxides were present in (II), (III), and (IV) oxidation states. The low preparation temperatures employed prevented further chromium oxidation to Cr(VI). Maximum surface areas of 439 m2/g were obtained. The materials efficiently removed AB (maximum experimental adsorption capacity of 44.4 mg/g) by means of electrostatic interaction caused by the positively charged distribution of the carbons. The adsorption capacity was not affected by temperature, but pH had a mixed effect due to the combination of a shift in surface charge distribution and dye speciation. The results demonstrated that it is possible to obtain a value-added product, i.e., carbons modified with chromium nanoparticles for dye removal, from a hazardous residue of the tanning industry.
KW - Acid Black 210
KW - Activated carbon
KW - Adsorption
KW - Chrome-tanned leather shavings
KW - Chromium oxides
KW - Dye
KW - Tannery
UR - http://www.scopus.com/inward/record.url?scp=85067403143&partnerID=8YFLogxK
U2 - 10.1007/s11270-019-4194-x
DO - 10.1007/s11270-019-4194-x
M3 - Artículo
SN - 0049-6979
VL - 230
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
IS - 7
M1 - 142
ER -