A PES Study of Factors Influencing Metal Partitioning in Aquatic Systems: “Design of Experiment As, Cd, Co, Cr, Cu, Pb, Ni, and Zn”

Mobility and bioavailability of heavy metals are related to their partitioning amongst suspended sediment and water. A Particle Entrainment Simulator (PES) is used to simulate sediment resuspention in natural surface water systems. The simulations were carried out under various conditions of water/suspended solids conditions. Five factors, each at various levels, are tested collectively: the pH of water at two levels (4 and 8), shear stress on bottom sediment at three levels (0.1, 0.3, and 0.5 N/m2 ) salinity of water at two levels (0.01 and 14.0 ppt), organic matter in sediment at three levels (0.50, 1.93, and 3.80%) and temperature at three levels 6, 15, and 30oC). The 3 3 x 22 factorial experiment was generated using Mini Tab 16® software. The metals evaluated in this study are the top eight metals commonly found in New England sediments. Each metal concentration was simulated at a level slightly higher than its Effective Range Median (ERM), above which, detrimental effects are frequently observed when exceeded. For the eight metals tested in this study, multiple regression equations are generated to predict the partition coefficient Kd of each metal under the various conditions of the five factors studied. The most significant factors influencing partitioning of each metal and the interactions between the factors were evaluated and validated