| Abstract: | Sorption by wool of mercuric nitrate, mercuric chloride, and methylmercuric chloride was measured by atomic absorption spectroscopy. Both inorganic mercury compounds are efficiently taken up at low concentrations from acid solution. The rate of binding from the nitrate is appreciably slower than from the chloride. Methylmercuric chloride is bound slowly at low pH, rapidly at pH 6. The extent of its binding is roughly 10% to 20% of that of the inorganic salts. The wool-bound mercury can be recovered by serial extraction with aqueous citrate or ethylenediaminetetraacetate at pH 6. The residual, firmly bound mercury is roughly equivalent to the sulfhydryl sulfur. Sorption of inorganic mercury compounds at low pH roughly follows a Freundlich isotherm in the concentration range 5×10-6 to 10?1M. Sorption of methylmercurie chloride at pH 6 follows a roughly parallel isotherm in the range 5×10?6 to 10?3M. These data suggest the potential value of wool and other animal keratins to remove and recover mercury from contaminated water. Wool may also serve as an instructive model for mercury binding and release in the body. |
