The mercury
remediation capacity of the immobilized cells is presented as
a function of the equilibrium concentration of mercuric ions within
the synthetic effluent medium in Fig. 2. The mercuric ions’ removal
capacity increased with the initial concentration of the mercury. It
is well documented that, in the beginning, the amount of metal
removed (per unit of cell mass) is directly proportional to the
amount of the metal ion present in the solution. The increase in the
uptake capacity with the increase in initial mercury concentration
may thus be attributed to the presence of a higher metal ion
concentration gradient. Also, the presence of a higher number of
initial vacant adsorption sites on the adsorbent, and the higher
probability of collisions between ions and sorbents, further assist
the remediation process. Similar results have been observed for
carbon sorbents derived from the fruit shell of Terminalia
catappa