Abstract: Pb adsorption capacities of Fe oxide, Mn oxide and organic materials
in natural surface coatings (biofilms and associated minerals) collected in
three lakes, two ponds and a river in Jilin Province, China and Cayuga Lake in
US were studied. A novel extraction technique was employed to remove one or
more component(s) from the surface coatings. Pb adsorption to surface coatings
before and after extraction was performed to determine the adsorptive
properties of the extracted component(s). The statistical analysis of observed
Pb adsorption was carried out using nonlinear least squares fitting (NLSF) to
estimate the Pb adsorption capacity of each component of surface coatings. For
each body of water, the estimated Pb adsorption capacity of Mn oxide (mol
Pb/mol Mn) was significantly higher than that of Fe oxide (mol Pb/mol Fe). The
value of estimated adsorption capacities of organic materials with the unit mol
Pb per kg COD was similar to or less than that of Fe oxides with the unit mol
Pb per mol Fe. Comparison of components of surface coatings in different waters
showed that the estimated Pb adsorption capacities of components in surface
coatings developed in different natural waters were different,especially for Mn
oxides.
Keywords: surface coatings, iron oxide, manganese oxide, organic material