Table 4: Effect of temperature on the ion exchange capacity of Zr(IV) tungstovanadate on heating time for 1 h.

Heating temperature (°C)AppearanceIEC for Na+ ion (mequiv.g−1)% loss in IEC

50Yellow 2.50
100Yellow 2.452
200Yellow 2.394.4
400Yellow 2.2510
500Dark yellow2.1516
600Dark yellow1.828
700Greenish yellow1.636