THE INFLUENCE OF SALTS ON THE ADSORPTION OF HUMIC ACIDS ONTO PREBUILT HYDROXIDE IRON FLOCS

The purpose of this study is to quantify the effect of sodium, potassium, calcium, magnesium salts (Chloride, sulphate, mono and dihydrogenphosphate) on the adsorptive capacity of preformed hydroxide metallic(Fe3+) flocs for humic substances (HS) and humic acids (HA) at differents experimental conditions (table 1). The addition of calcium ions shows an increase of adsorption capacity of HS and HA onto preformed hydroxide flocs, than Mg2+ and Na+ ions have no effect. Sulphate and hydrogen phosphate ions diminish the adsorption capacity. Results are importants for water treatment and are discussed in accordance with the variation of electrokinetics potential of flocs particles.