Vol.3, No 1, 2004 pp. 79 - 85
UDC 621.385, 677.027
DESTABILIZATION AND AGGREGATION
OF AQUEOUS HUMIC ACIDS SOLUTION BY METAL IONS
Tatjana Anđelković1, Jelica Perović1,
Milovan Purenović1, Darko Anđelković2
1Faculty of Science, Dept. of Chemistry,
Ćirila i Metodija 2, YU-18000 Niš
2JKP "Naissus", Oktobarske revolucije
1/1, YU-18000 Niš
Abstract. The aggregation of soil humic acid (HA) after addition
of cations was investigated by nephelometric measurements of HA solution
turbidity. Here we show that aggregation is promoted by the presence of
positive ions in the solution and that the order of increasing effectiveness
in turbidity follows Schulze-Hardy rule. Also, the obtained results indicate
that the cation with the largest ionic radius within a common valence is
the most effective coagulant. Influence of anions follows the sequence:
chloride < nitrate < sulphate, but it is insignificant comparing
the influence of cation. This confirms that HA molecules are of negative
charge.
Key words: cation, humic acid, aggregation, turbidity
DESTABILIZACIJA I AGREGACIJA
VODENOG RASTVORA HUMINSKIH KISELINA METALNIM JONIMA
Agregacija terestrične huminske kiseline nakon dodatka katjona je ispitana
nefelometrijskim merenjem mutnoće rastvora huminskih kiselina. Agregacija
je pospešena prisustvom pozitivnih jona u rastvoru, pri čemu doprinos različitih
metalnih jona porastu mutnoće, samim tim agregacije HA, sledi Šulc-Hardijevo
pravilo. Takođe, dobijeni rezultati pokazuju da će od katjona iste valentnosti,
katjon sa najvećim jonskim radijusom pokazivati najveću moć agregacije
HA molekula. Redosled uticaja anjona na agregaciju je sledeći: hlorid <
nitrat < sulfat, mada je on zanemarljiv u odnosu na uticaj katjona.
Ovo potvrđuje da su HA molekuli negativnog naelektrisanja.
