Equilibrium partitioning of heavy metals in dutch field soils. I. relationship between metal partition coefficients and soil characteristics

摘要

Twenty Dutch soils were sampled at sites that were expected to have elevated levels of heavy metals compared to background values. Field-based partition coefficients (K_p) for As, Cd, Cr, Cu, Ni, Pb, and Zn were determined by calculating the ration of the amount of metal extracted by concentrated HNO_3 to the metal concentration in the pore water. K_p values varied widely with metal and soil type and correlated well with soil pH. To a lesser extent amorphous Fe-content and dissolved organic carbon (DOC) also explained part of the variation in K_p values. Thereupon, regression equations based on easily obtainable soil characteristics were derived. External validation of the regression equations showed that predicted log K_p values were in agreement with measured values.