Izvorni znanstveni članak
Formation and Morphology of Struvite and Newberyite in Aqueous Solutions at 25 and 37 °C
Jasminka Kontrec
Vesna Babić-Ivančićand
Ljerka Brečević
Sažetak
The influence of the initial reactant concentrations (ci(Mg)tot = 5.0 x 10–6 to 5.0 x 10–1 mol dm–3, ci(P)tot = ci(NH4)tot = 1.0 x 10–3 to 5.0 x 10–1 mol dm–3) and temperature (25 and 37 °C) on the composition and morphology of the precipitates formed in the system MgCl2-NH4H2PO4-NaOH-H2O at initial pHi = 7.40 has been investigated. Precipitation diagrams are presented showing the concentration regions within which different morphologies of solid phase have been formed. The solid phases aged for 24 hours were characterized by means of optical microscopy, FT-IR spectrophotometry, X-ray diffractometry and thermogravimetry. It was found that struvite was a predominant phase formed within the concentration region examined and newberyite was obtained only in the region where pH24h < 6.5. The influence of the initial pH on the formation and transformation of these two compounds were studied in the region 5.0 pHi ≤ 9.0 and the results
are discussed.
Ključne riječi
struvite; newberyite; precipitation; morphology
Hrčak ID:
5193
URI
Datum izdavanja:
15.6.2005.
Posjeta: 2.561 *