ABSTRACT
In this study the intercalation behavior of di- and trivalent cations like Cu(II), Mg(II), Zn(II), and Al(III) into the interlayers of muscovite was investigated by X-ray diffraction and far-infrared spectroscopy. The X-ray diffractometry shows that the original material is a muscovite 2M(1). During the metal cation treatment, new peaks occur at about 1.1 and 2.2 nm, while the original peaks strongly decrease. This gives evidence for the formation of a strongly modified mica structure. The occurrence of bands at low wavenumbers (93 cm(-1) and 104 cm(-1)) in the far-infrared spectra show that the untreated material was partly dehydroxylated. The strong decrease of the band at 93 cm(-1) and the occurrence of a band at 110 cm(-1) during the intercalation are strong hints about the rehydroxylation of the mineral. The strong increase of the band intensity at 88 cm(-1) and the occurrence of a band at 119 cm(-1) in the treated muscovites prove the formation of a new, strongly modified mica phase that has both the new cations and the potassium incorporated into the interlayer space.
ABSTRACT
For phosphorus recovery from wastewater, the present paper aims at understanding the crystallization of calcium phosphate by using calcites (Juraperle and Coccolith) as seeds from hard water. Synthetic hard water with 60 mgCl(-1) carbonate and 10 mgPl(-1) phosphate was prepared and used in the batch experiments of calcite-seeded crystallization. The solution composition was measured throughout the batch crystallization process, and the corresponding saturation indices with respect to the minerals were calculated with PHREEQC Program. The surface of the calcite seeds was observed and measured with environmental scanning electron microscopy (ESEM), Fourier transform infrared (FTIR) and BET method. The studies show that both calcites are effective seeds for the crystallization of calcium phosphate from hard water; the used calcites are more efficient than the original ones because newly formed crystals with calcium phosphate have covered their surfaces. The studies show that the calcite seeds can be used for phosphorus recovery from hard waters.
