Chemical Engineering Journal, Vol.191, 141-146, 2012
Montmorillonite modified with hexadecylpyridinium chloride as highly efficient anion exchanger for perchlorate ion
Details of the anion-exchange properties of Na-montmorillonite modified with hexadecylpyridinium chloride (HDPyCl-montmorillonite) for perchlorate ions are reported herein. The perchlorate uptake on HDPyCl-montmorillonite from 0.01 mmol/dm(3) or 0.10 mmol/dm(3) solution rapidly attained equilibrium within 4 h. The perchlorate uptake on HDPyCl-montmorillonite followed the Langmuir isotherm model with capacity of 1.02 mmol/g. The perchlorate uptake of 0.70-0.80 mmol/g on HDPyCl-montmorillonite persisted in a wide pH range of 4-10. High selectivity of HDPyCl-montmorillonite for perchlorate ion was reflected in the high distribution coefficient values (>10(4) cm(3)/g) with selectivity sequence of HPO42- < SO42- < NO3-