TY - JOUR
T1 - Calcium and hydrogen effects during sorption of copper onto an alginate-based ion exchanger
T2 - Batch and fixed-bed column studies
AU - An, Byungryul
AU - Son, Hyunjin
AU - Chung, Jaeshik
AU - Choi, Jae Woo
AU - Lee, Sang Hyup
AU - Hong, Seok Won
N1 - Funding Information:
This study was supported by the Korea Ministry of Environment as “The Eco-Innovation Program” (No. 2012001340002).
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/10
Y1 - 2013/10
N2 - The characteristics of alginate beads in calcium (Ca2+) and hydrogen (H+) form were studied with respect to the uptake of copper ions (Cu2+) via batch and fixed-bed column experiments. The maximum Cu2+ sorption capacities (Qmax) of calcium and hydrogen alginates (abbreviated as CA and HA, respectively) were found to be 107mg/g and 189mg/g, respectively. At pH 5, more than 95% of Cu2+ was removed, but the amount of Cu2+ sorbed onto CA beads was significantly lowered at pH 2 owing to the pKa value of carboxylic acid. When Ca2+, as a competing ion, was present in solution at a molar ratio of Ca2+ to Cu2+ equal to 8, Qmax was drastically decreased to 20mg/g. A faster equilibrium time (24h) was also observed for HA beads compared to CA beads (48h). In a fixed-bed column packed with CA beads, the breakthrough of Cu2+ occurred immediately with the presence of Ca2+ in the model wastewater. Using HA beads, however, the first breakthrough of Cu2+ appeared after 900 bed volumes. These results suggested that HA beads were more effective than CA beads in reducing the adverse influence of competing cations such as Ca2+ during the initial period of Cu2+ sorption. Moreover, the breakthrough of Cu2+ occurred later than that of Ca2+ due to a higher selectivity of Cu2+ over Ca2+, which was confirmed by a separation factor (αCu/Ca, 10.3) of HA beads. In addition, their reusability was confirmed via ten regeneration cycles.
AB - The characteristics of alginate beads in calcium (Ca2+) and hydrogen (H+) form were studied with respect to the uptake of copper ions (Cu2+) via batch and fixed-bed column experiments. The maximum Cu2+ sorption capacities (Qmax) of calcium and hydrogen alginates (abbreviated as CA and HA, respectively) were found to be 107mg/g and 189mg/g, respectively. At pH 5, more than 95% of Cu2+ was removed, but the amount of Cu2+ sorbed onto CA beads was significantly lowered at pH 2 owing to the pKa value of carboxylic acid. When Ca2+, as a competing ion, was present in solution at a molar ratio of Ca2+ to Cu2+ equal to 8, Qmax was drastically decreased to 20mg/g. A faster equilibrium time (24h) was also observed for HA beads compared to CA beads (48h). In a fixed-bed column packed with CA beads, the breakthrough of Cu2+ occurred immediately with the presence of Ca2+ in the model wastewater. Using HA beads, however, the first breakthrough of Cu2+ appeared after 900 bed volumes. These results suggested that HA beads were more effective than CA beads in reducing the adverse influence of competing cations such as Ca2+ during the initial period of Cu2+ sorption. Moreover, the breakthrough of Cu2+ occurred later than that of Ca2+ due to a higher selectivity of Cu2+ over Ca2+, which was confirmed by a separation factor (αCu/Ca, 10.3) of HA beads. In addition, their reusability was confirmed via ten regeneration cycles.
KW - Calcium competition
KW - Copper sorption
KW - Fixed-bed column
KW - Hydrogen alginate
KW - Regeneration
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U2 - 10.1016/j.cej.2013.07.079
DO - 10.1016/j.cej.2013.07.079
M3 - Article
AN - SCOPUS:84882776570
VL - 232
SP - 51
EP - 58
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
ER -