Gill carrier transport

Crustaceans can accumulate zinc from both water and food (USEPA 1987). In uncontaminated waters, the diet is probably the major source of zinc. Absorption from the stomach is efficient and occurs, in part, via the hepatopancreas. When a large pulse of zinc reaches the blood from the stomach, some is excreted, but much is resorbed and stored in the hepatopancreas in a relatively nonlabile form. Ultimately, stored zinc is also excreted, although removal via the gut is unimportant (Bryan et al. 1986). Zinc absorption occurs initially at the gill surface, followed by transport on a saturable carrier in the cell wall, and is most efficient at low dissolved ambient zinc concentrations. Urinary excretion is an important body removal pathway, especially at high dissolved ambient concentrations when it can account for 70 to 80% of total zinc excretion (Bryan et al. 1986). 

Gill (1972) was the first to suggest that charge transport in polymers occurred by polaron hopping. The application of polaron theory to transport in polymers was first described by Sahvun (1984). Schein et al. (1990), and Schein (1992). The models described by Sahvun and Schein and coworkers lead to a mobility that is a product of a Boltzmann probability of energy coincidence and the probability a carrier will hop to an adjacent site by thermal activation once... 

Gill, J.S., Marwah, UR. Mishra, B.M. (1994) Transport of samarium(III) and uraniinn(VI) across a silicone-supported liquid membrane using di(2-ethylhexyl)phosphoric acid and tributyl phosphate as mobile carriers. Separation Science and Technology, 29 (2), 193-203. 

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