Abstract
Adsorption of quinoline (pKa = 4.92) and background electrolyte (CaCl2) onto specimen kaolinite and montmorillonite were measured as a function of pH (3-7.5) and ionic strength (1-10 mM), and as a function of quinoline concentration (0.2-1.55 mM) at fixed pH values of maximum adsorption. Maximum sorption of quinoline occurred at pH 3.5-4.0 for kaolinite, and pH 3.0-5.0 for montmorillonite. At their respective pH values of maximum adsorption, the sorption capacity for quinoline was 100 times greater with montmorillonite than kaolinite on a mass basis. Selectivity coefficients, which were calculated from pH edge data, indicated selectivity for cationic quinoline (QH+) over Ca2+ was greater with montmorillonite (Kexc = 27 at pH 4) compared to kaolinite (Kexc = 1.6 at pH 4), and Kexc was not affected by ionic strength for either clay. The results indicate the important role of charged siloxane sites in the adsorption of this N-heterocyclic contaminant.
Original language | English (US) |
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Pages (from-to) | 59-68 |
Number of pages | 10 |
Journal | Environmental Engineering Science |
Volume | 19 |
Issue number | 2 |
DOIs | |
State | Published - 2002 |
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Waste Management and Disposal
- Pollution