Abstract: Collogens in the pseudopodia and organic matters in the shell of the agglutinated foraminifera play key roles in the capturing and preserving of special detrital minerals. However, the relative mechanism and environmental implications are still not well understood. In this study, adsorption experiments were conducted to investigate the efficiency, thermodynamics, kinetics, the effect of solution pH on the adsorption of collogen, and the effect of adsorbed collogen on the adsorption of heavy metals by minerals, were conducted. Results showed that the equilibrium time of collogen adsorption by quartz and albite is 25 h, while that by rutile is about 12 h. The adsorption can be described by the quasi-second-order dynamics equation for all the three minerals. As for adsorption thermodynamics, quartz and albite are more in line with the Freundlich equation, while rutile is in line with the Langmuir equation. The order of the maximum adsorption capacity for three minerals is rutile>albite>quartz. At pH=3.0, both albite and rutile obtain respective maximum collogen adsorption capacity; while for quartz, the adsorption capacity is unrelated to the solution pH. Generally, the immobilization abilities of Zn and Cu by three minerals are enhanced after the modification of mineral surface by the adsorbed collogen. The results indicated that the agglutinated foraminifera can achieve the targets of selectively capturing and locking minerals through decreasing pH, and the effect of organic matters should be considered when the foraminifera shells are introduced for tracing the heavy metal concentrations.

Key words: mineral, collogen, adsorption, influence factor, environmental implication