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Efficient and safe disposal of chrome shavings discharged from leather industry using thermal combustion
Author(s) -
Swarnalatha Somasundaram,
Ganesh Kumar Arumugam,
Tandaiah Srinivasulu,
Sekaran Ganesan
Publication year - 2009
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.2108
Subject(s) - leachate , chromium , incineration , portland cement , combustion , toxicity characteristic leaching procedure , leaching (pedology) , cement , waste management , chemical oxygen demand , calcination , compressive strength , materials science , metallurgy , environmental science , environmental chemistry , chemistry , metal , environmental engineering , wastewater , composite material , biochemistry , organic chemistry , soil science , engineering , catalysis , soil water
BACKGROUND: The high concentration of trivalent chromium along with organic/inorganic compounds in shavings (ChS) discharged from leather industries causes severe groundwater contamination in land disposal and chronic air pollution during thermal incineration. In the present investigation, ChS were subjected to incineration at 800 °C in a thermal incinerator under different volumes of oxygen to optimize the flow rate of oxygen to prevent the conversion of Cr 3+ to Cr 6+ (starved air combustion) followed by solidification and stabilization of calcined shavings. RESULTS: Net energy changes resulting from the combustion of shavings showed that the energy of the organic fractions is utilized to the maximum extent at an O 2 flow rate of 3.0 g min −1 . The ChS were effectively solidified/stabilized using Portland cement and fine aggregate. The unconfined compressive strength of the blocks was in the region of 160 kg cm −2 . Leachability studies using a toxicity characterization of leachate procedure test (TCLP) on a solidified block were carried out to determine the percentage metal fixation and dissolved organic (as chemical oxygen demand) concentration in the leachate. CONCLUSION: The stabilization of chromium(III) in the cement gel matrix was confirmed using different instrumental techniques. The leaching characteristics through TCLP confirmed the effective stabilization of chromium; i.e., the metal fixing capacity was 99.95%. Copyright © 2009 Society of Chemical Industry