TY - JOUR
T1 - Selectivity of bicarbonate-form anion exchange for drinking water contaminants
T2 - Influence of resin properties
AU - Hu, Yue
AU - Foster, Jerrine
AU - Boyer, Treavor H.
N1 - Funding Information:
This publication was made possible by USEPA grant R835334. Its contents are solely the responsibility of the grantee and do not necessarily represent the official views of the USEPA. Further, USEPA does not endorse the purchase of any commercial products or services mentioned in the publication. The authors thank Judith Labrada for assistance with laboratory work.
Publisher Copyright:
© 2016 Elsevier B.V. All rights reserved.
PY - 2016/5/11
Y1 - 2016/5/11
N2 - Bicarbonate was investigated as a new counterion for six strong-base anion exchange resins considering the selective removal of six drinking water contaminants: Nitrate, bromide, perchlorate, sulfate, chromate, and Suwannee River natural organic matter (SRNOM). The most selective bicarbonate-form resin for each contaminant was evaluated based on qualitative binary ion exchange plots and quantitative separation factor calculation. The influence of resin properties and ion characteristics was evaluated on resin selectivity for each contaminant. The type of functional group and polymer composition of the resin were shown to influence selectivity for inorganic contaminants, and the pore structure and polymer composition of resin were shown to influence selectivity for SRNOM. Bicarbonate-form resin with wide spacing of functional groups (i.e., triethylamine) and polystyrene composition was favorable for monovalent, hydrophobic contaminants, including nitrate, bromide, and perchlorate, whereas resin with close spacing of functional groups (i.e., trimethylamine) and polystyrene composition was favorable for relatively hydrophobic chromate and resin with same functional group and polyacrylic composition was favorable for relatively hydrophilic sulfate ion. For organic contaminant, bicarbonate-form resin with macroporous structure and polyacrylic composition was most selective for SRNOM. In addition, the resin selectivity sequence for each contaminant based on separation factor calculations was compared with adsorption isotherm parameters, and the similarities and differences are discussed. The separation factor method is based on ion exchange stoichiometry, whereas adsorption method is robust in terms of simplifying calculation.
AB - Bicarbonate was investigated as a new counterion for six strong-base anion exchange resins considering the selective removal of six drinking water contaminants: Nitrate, bromide, perchlorate, sulfate, chromate, and Suwannee River natural organic matter (SRNOM). The most selective bicarbonate-form resin for each contaminant was evaluated based on qualitative binary ion exchange plots and quantitative separation factor calculation. The influence of resin properties and ion characteristics was evaluated on resin selectivity for each contaminant. The type of functional group and polymer composition of the resin were shown to influence selectivity for inorganic contaminants, and the pore structure and polymer composition of resin were shown to influence selectivity for SRNOM. Bicarbonate-form resin with wide spacing of functional groups (i.e., triethylamine) and polystyrene composition was favorable for monovalent, hydrophobic contaminants, including nitrate, bromide, and perchlorate, whereas resin with close spacing of functional groups (i.e., trimethylamine) and polystyrene composition was favorable for relatively hydrophobic chromate and resin with same functional group and polyacrylic composition was favorable for relatively hydrophilic sulfate ion. For organic contaminant, bicarbonate-form resin with macroporous structure and polyacrylic composition was most selective for SRNOM. In addition, the resin selectivity sequence for each contaminant based on separation factor calculations was compared with adsorption isotherm parameters, and the similarities and differences are discussed. The separation factor method is based on ion exchange stoichiometry, whereas adsorption method is robust in terms of simplifying calculation.
KW - Adsorption isotherm
KW - Anion exchange
KW - Bicarbonate
KW - Selectivity sequence
KW - Separation factor
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U2 - 10.1016/j.seppur.2016.02.030
DO - 10.1016/j.seppur.2016.02.030
M3 - Article
AN - SCOPUS:84959525516
SN - 1383-5866
VL - 163
SP - 128
EP - 139
JO - Separation and Purification Technology
JF - Separation and Purification Technology
ER -