Use of Na-modified clinoptilolite for the removal of terbium ions from aqueous solution

In this study, Na-modified Transcarpathian clinoptilolite was used for preconcentration of trace amoun ts of terbium(III) ions from aqueous solutions. The sorbent was characterized by thermogravimetric analysis. The influence of the preliminary thermal treatment on the sorption activity of Na-modified clinoptilolite was thoroughly investigated. In addition, it was found that such characteristics of the solution as the te rbium concentration, acidity, and ion strength have an ef fect on the sorption capacity of the zeolite in dyn amic conditions. The optimum pH range of the solution was found to be 8.8-9.0. A p reliminary thermal treatment of Na-clinoptilolite in the temperature range 475-700°C increased the sorption capacity of the sorbent . 7M nitric acid, 6M hydrochloric acid, and 1M NaCl solutions were identified as effective desorbents of terbium(III) ions from Na-clinoptilolite. Furthermo re, the influence of the most common ions on the up take capacity of the sorbent was evaluated.