ADSORPTION BEHAVIOR OF PHENOL FOR MONO, BIS AND TRIS(2,2′-BIPYRIDINE)NICKEL(Ⅱ)- AND TRIS(ETHYLENEDIAMINE)NICKEL(Ⅱ)-SAPONITE INTERCALATION COMPOUNDS FROM AQUEOUS SOLUTION

摘要

Adsorption of phenol on mono, bis and tris(2,2′-bipyridine)nickel(Ⅱ)- and tris(ethylenediamine)-nickel(Ⅱ)-saponite intercalation compounds from aqueous solution was examined. Mono, bis and tris(2,2′-bipyridine)nickel(Ⅱ)-saponites were prepared by the reactions of Ni(Ⅱ)-form of a synthetic saponite (Sumecton SA) with 2,2′-bipyridine at the molar 2,2′-bipyridine to Ni(Ⅱ) ratios of 1:1, 2:1 and 3:1. Tris(ethylenediamine)nickel(Ⅱ)-saponite was prepared by the reactions of the Ni(Ⅱ)-saponite with ethylenediamine at the molar ratio of 3:1 (ethylenediamine:Ni(Ⅱ)). X-Ray diffraction and thermal analysis indicated that 2,2′-bipyridine and ethylenediamine were intercalated into Ni(Ⅱ)-saponite to form mono, bis and tris(2,2′-bipyridine)nickel(Ⅱ) and tris(ethylenediamine)nickel(Ⅱ) complexes. The adsorption isotherms of phenol for the mono, bis and tris(2,2′-bipyridine)nickel(Ⅱ)-saponites followed Langmuir type, indicating strong adsorbate-adsorbent interactions. The basal spacings of the mono, bis and tris(2,2′-bipyridine)nickel(Ⅱ)-saponites did not change by the adsorption of phenol, indicating that the adsorbed phenol existed in the interlayer micropore formed by the pillaring with the complexes. The adsorption of phenol on the tris(ethylenediamine)nickel(Ⅱ)-saponite was less effective than those on the (2,2′-bipyridine)nickel(Ⅱ)-saponites, suggesting that the interactions between pyridine rings and phenol played an important role in the adsorption of phenol.