TY - JOUR
T1 - Optimization of the conditions for the Cr (III) adsorption on activated carbon
AU - Lyubchik, Svetlana B.
AU - Perepichka, Irene I.
AU - Galushko, Olga L.
AU - Lyubchik, Andrey I.
AU - Lygina, Elena S.
AU - Fonseca, Isabel M.
N1 - Authors are thankful to NATO Science for Peace Programme SfP project 977984 and FCT Programme, SFRH/BPD/7150/2001, Portugal for the financial support.
PY - 2005/11/1
Y1 - 2005/11/1
N2 - In order to understand the patterns of the adsorption equilibrium of Cr (III) on activated carbon, the adsorption process was studied by two different ways: classical batch experiments on commercial Norit and Merck activated carbons and their oxidized forms in a wide range of pHs; and extended time-based tests at the same pH values on the same adsorbents. This approach allowed us to understand the role of texture, chemical carbon surface functionality and experimental conditions (initial pH of the solution, contact time and adsorbate/adsorbent ratio) on the effectiveness of Cr (III) removal. The adsorption process of Cr (III) at (24 ± 1C) on Merck and Norit activated carbons and their oxidized forms were studied at pH values between 1.5 and 5 (either adjusted or buffered). Chromium concentration was fixed at 200 ppm. The carbon loading ranged from 1.2 to 20 g/l. The carbon/Cr (III) solution contact time was varied from 0.5-1 month to 5 months, to ensure that the saturation of the carbon level was reached. According to the data obtained, the presence of carboxylic groups on carbon surface seems to enhance Cr (III) uptake at initial pH of the solution in the range between 2 and 4. Depending on the nature of the adsorbent surface chemistry, the contact time to reach equilibrium may range from 3 to 5 months. There is an optimum carbon loading which limits the Cr (III) uptake/removal at given pH value. In order to understand the adsorption process, an ion exchange, surface complex and surface precipitation were considered.
AB - In order to understand the patterns of the adsorption equilibrium of Cr (III) on activated carbon, the adsorption process was studied by two different ways: classical batch experiments on commercial Norit and Merck activated carbons and their oxidized forms in a wide range of pHs; and extended time-based tests at the same pH values on the same adsorbents. This approach allowed us to understand the role of texture, chemical carbon surface functionality and experimental conditions (initial pH of the solution, contact time and adsorbate/adsorbent ratio) on the effectiveness of Cr (III) removal. The adsorption process of Cr (III) at (24 ± 1C) on Merck and Norit activated carbons and their oxidized forms were studied at pH values between 1.5 and 5 (either adjusted or buffered). Chromium concentration was fixed at 200 ppm. The carbon loading ranged from 1.2 to 20 g/l. The carbon/Cr (III) solution contact time was varied from 0.5-1 month to 5 months, to ensure that the saturation of the carbon level was reached. According to the data obtained, the presence of carboxylic groups on carbon surface seems to enhance Cr (III) uptake at initial pH of the solution in the range between 2 and 4. Depending on the nature of the adsorbent surface chemistry, the contact time to reach equilibrium may range from 3 to 5 months. There is an optimum carbon loading which limits the Cr (III) uptake/removal at given pH value. In order to understand the adsorption process, an ion exchange, surface complex and surface precipitation were considered.
KW - Activated carbon
KW - Adsorption
KW - Heavy metals
KW - Surface chemistry
UR - http://www.scopus.com/inward/record.url?scp=29144445124&partnerID=8YFLogxK
U2 - 10.1007/s10450-005-5616-1
DO - 10.1007/s10450-005-5616-1
M3 - Article
AN - SCOPUS:29144445124
VL - 11
SP - 581
EP - 593
JO - Adsorption-Journal Of The International Adsorption Society
JF - Adsorption-Journal Of The International Adsorption Society
SN - 0929-5607
IS - 5-6
T2 - 5th Brazilian Meeting on Adsorption
Y2 - 18 July 2004 through 21 July 2004
ER -