Effect of Ion-Exchanged Zeolite on the Deposition of Particulate Soil on Cloths

Abstract

Ca-Zeolite and Mg-Zeolite are formed in natural hard water by exchanging Na⁺ in Na-Zeolite with Ca²⁺ and Mg²⁺.
In this paper, the effect of these exchanged Zeolite on the deposition of particulate soil were investigated by using the artificially prepared Ca- and Mg-Zeolites from CaCl₂ and MgCl₂ solution (residual Na-Zeolite are estimated ca. 30%).
Main results obtained are summarized as follows :
1) When Mg-Zeolite or Ca-Zeolite of the same exchange ratio was added to Ca-containinghard water, both Zeolites removed Ca²⁺ ions and their removal efficiencies were in the order of Mg-Zeolite > Ca-Zeolite.
2) In aqueous Fe₂O₃ suspension (0°DH), the deposition of Fe₂O₃ on cloths depended on the kind of Zeolite, and the amount of deposition decreased in the order of Ca-Zeolite > Mg-Zeolite > Na-Zeolite.
3) In Ca-containing hard water less than 30°DH, the deposition amount of Fe₂O₃ decreased in the order of Ca-Zeolite >Mg-Zeolite >Na-Zeolite according to the kind of added Zeolite.
In Ca-containing hard water which exceeds the ion binding capacity of Na-Zeolite, the deposition of Fe₂O₃ increased remarkably.
This phenomenon suggests that the deposition of particulate soil is affected by the presence of exchanged Zeolite and the concentration of Ca²⁺ ion.