Dataset: Po, Pb and Be partition coefficients on nanoparticles from laboratory experiments

Improved applications of 210Po, 210Pb and 7Be as geochemical proxies require more detailed understanding
of their interactions with particles. Here, laboratory sorption experiments were carried out to examine
the adsorption of 210Po, 210Pb and 7Be and their fractionation on inorganic nanoparticles, including SiO2,
CaCO3, Al2O3, TiO2 and Fe2O3, in the presence or absence of macromolecular organic compounds (MOCs)
that include humic acids (HA), acid polysaccharides (APS) and proteins (BSA), in natural seawater. Results
showed that nanoparticle sorption was not greatly enhanced over that of microparticles as would
be expected from their much higher specific surface areas, likely indicating their aggregation in seawater.
It was found that synergistic interactions between inorganic nanoparticles, MOCs, and radionuclides
determined the sorption, although their adsorption was particle composition-dependent. MOCs enhanced
the sorption of selected nuclides on most nanoparticles. On average, in the presence of MOCs, partition
coefficients (Kc ) of 210Po, 210Pb, and 7Be on nanoparticles increased 2.9-, 5.0- and 5.9-fold, respectively.
The effect of MOCs could be explained for 210Po and 210Pb from their different log Kc values on inorganic
nanoparticles. In addition, fractionation effects between 210Po and 210Pb (or between 210Pb and 7Be)
could be quantified from their relative log Kc values on end-member sorbent components. Applications
of both 210Po–210Pb and 7Be–210Pb pairs as particle dynamics tracers could be more quantitative when
the nature of the organic coatings is taken into account.