The adsorption kinetics of metal ions onto different microalgae and siliceous earth

• Published in: Water research (Oxford) Vol. 35; no. 3; pp. 779 - 785
• Main Authors: Schmitt, Daniel, Müller, Andreas, Csögör, Zsuzsa, Frimmel, Fritz H, Posten, Clemens
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2001; Elsevier Science
• Subjects: adsorbents; Adsorption; Aluminum; Aluminum - pharmacokinetics; Animal, plant and microbial ecology; Applied ecology; Applied sciences; bioaccumulation; Biological and medical sciences; Biological and physicochemical phenomena; biosorption; Cadmium; Cadmium - pharmacokinetics; Chlorophyta; Chlorophyta - metabolism; Copper; Copper - pharmacokinetics; Cyclotella; Cyclotella cryptica; Diatoms; Diatoms - metabolism; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Engineering and environment geology. Geothermics; Eukaryota; Eukaryota - metabolism; Exact sciences and technology; Fresh water environment; Fundamental and applied biological sciences. Psychology; Kinetics; Lead; Lead - pharmacokinetics; mathematical models; mercury; Mercury (metal); Mercury - pharmacokinetics; metabolism; metal ions; metals; microalgae; Natural water pollution; Phaeodactylum tricornutum; pharmacokinetics; Pollution; Pollution, environment geology; Porphyridium purpureum; Rate constants; Rhodophyta; Rhodophyta - metabolism; Scenedesmus; Scenedesmus subspicatus; silica; Soil; Water treatment and pollution; Zinc; Zinc - pharmacokinetics; microalgae; metals; adsorption; bioaccumulation; kinetics; biosorption; Pollutant behavior; Algae; Metal Ions; Phaeodactylum tricornutum; Bioadsorbents; Experimental study; Silica; Freshwater environment; Heterokontophyta; Bacillariophyta; Adsorption; Water pollution; Kinetics; Biological accumulation; Thallophyta
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/S0043-1354(00)00317-1

In the present work the adsorption kinetics of the six metal ions aluminum, zinc, mercury, lead, copper, and cadmium onto living microalgae were measured. The freshwater green microalga Scenedesmus subspicatus, the brackish water diatom Cyclotella cryptica, the seawater diatom Phaeodactylum tricornutum, and the seawater red alga Porphyridium purpureum were the subject of investigation. In most cases the adsorption rate of the metals could be well described by using the equation of the Langmuir adsorption rate expression. Inverse parameter estimation allowed the determination of the rate constants of the adsorption process and the maximum metal content of the algae. The highest values for the rate constant were obtained for Porphyridium purpureum followed by Phaeodactylum tricornutum. High values for the maximum content were obtained for Cyclotella cryptica and Scenedesmus subspicatus. The maximum rate constant was 24.2 l h −1 for the adsorption of Hg to Porphyridium purpureum whereas the maximum metal content (0.243 g g −1) was obtained for Zn on Cyclotella cryptica. A comparison of these values with those obtained for the mineral siliceous earth exhibiting low maximum content and high adsorption rates reveals that the mechanism of adsorption onto the algae is a mixture of adsorption and accumulation.