engleski

Adsorption of Sulfated Polysaccharides on Mercury and gamma-Al2O3 Particles in Sodium Chloride Solution and Seawater

The adsorption of Dextran sulfate and natural sulfated polysaccharides from algal sources, thau-, kapa- and lhambda- carrageenans on the mercury surface and on the gamma-Al2O3 particles were studied by out of phase a.c. voltammetry. On the mercury surface the adsorption of Dextran sulfate and adsorption of carrageenas are of the similar extent. The comparative studies of the adsorption of polysaccharides on aluminum particles showed a high affinity of thau-carrageenan and Dextran- sulfate for gamma-Al2O3 particles (Gamma=300 mg/g and 95 mg/g, respectively). The adsorption studies was conducted at the pH value of natural waters (pH=4 and pH=7.9) in 0.55 M NaCl and in natural seawater. The adsorption properties of carrageenans are changed in seawater in respect to the adsorption in 0.55 M NaCl due to the partial neutralization of sulfate groups by Ca and Mg ions present in the seawater. This is obvious especially for thau- carrageenan. The results support the features already observed in the formation of the so called marine snow, i.e fast transformation and removal of polysaccharides onto hydrophobic and hydrophilic particles and their transport to the sea bottom.

Sulfated Polysaccharides ; mercury surface

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