[Complexation of Ca++ by humic substances extracted from a natural peat and from a peat treated with nitrogen oxides] | Complexation du Ca++ par les substances humiques extraites de tourbe naturelle et de tourbe traitee aux oxydes d'azote
1999
Kaemmerer, M. | Guiresse, M. | Brun, G. | Seibane, L. | Revel, J.C. (Ecole Nationale Superieure Agronomique de Toulouse (France)) | Hafidi, M. (Department de Biologie, Marrakech (Morocco))
anglais. The study of the complexation of calcium by humic substances (SH) extracted from a natural peat (TN) and from a peat treated with nitrogen oxides (TT) was followed by conductimetry and potentiometry with pH variable and pH constant. The complexing capacity increases as the pH rises: complexed calcium is 130 cmol kg*[-1) SH (TN) and 135 cmol kg*[-1) SH (TT) with pH 5, and 330 cmol kg*[-1) SH (TN) and 410 cmol kg*[-1) SH (TT) with pH 9. These reactions involve various functional groupings of pKa1 4 for TN and TT, pKa2
Afficher plus [+] Moins [-]italien. [E' stato condotto lo studio della complessazione del calcio da parte di sostanze umiche estratte da una torba naturale (TN) e da una torba trattata con ossidi di azoto (TT) mediante conduttometria e potenziometria a pH variabile e a pH costante. La capacita' complessante aumenta all'aumentare del pH: il calcio complessato ammonta a 130 cmol kg*[-1) S.H. e a 135 cmol kg*[-1) S.H. (TT) a pH 5, a 330 cmol kg*[-1) S.H. (TN) e a 410 cmol kg*[-1) S.H. (TT) a pH 9. Queste reazioni interessano vari gruppi funzionali di pKa1 4 per TN e TT, pKa2
Afficher plus [+] Moins [-]Mots clés AGROVOC
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