Competitive Removal of Cd2+ and Hg2+ Ions from Water Using Titanosilicate ETS-4: Kinetic Behaviour and Selectivity

authors	Cardoso, SP; Lopes, CB; Pereira, E; Duarte, AC; Silva, CM
nationality	International
journal	WATER AIR AND SOIL POLLUTION
author keywords	Cadmium; Ion competition; ETS-4; Ion exchange; Kinetic; Mercury
keywords	POROUS TITANOSILICATE; EXCHANGE PROPERTIES; CRYSTAL-STRUCTURES; AQUEOUS-SOLUTION; PHARMACOSIDERITE
abstract	Mercury and cadmium are priority hazardous substances. Some titanosilicates have been tested for the removal of Cd2+ and Hg2+ from single solutions by ion exchange. In this work, the competition between both contaminants for the exchanger binding sites of titanosilicate Engelhard titanosilicate material number 4 (ETS-4) was studied by performing batch experiments with aqueous solutions containing the two counter ions. The results evidenced the large capacity of ETS-4 and shown that the cadmium(II) diffusivity through the sorbent is higher than that of mercury(II). Furthermore, the ETS-4 exhibited higher kinetic and equilibrium selectivities for Cd2+, which attained values in the ranges 8.9-12.5 and 7.9-12.8, respectively. With respect to modelling, the pseudo-second-order equation described successfully the competitive removal of Cd2+ and Hg2+.
publisher	SPRINGER
issn	0049-6979
year published	2013
volume	224
issue	5
digital object identifier (doi)	10.1007/s11270-013-1535-z
web of science category	Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources
subject category	Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources
unique article identifier	WOS:000319161400014