The transport, transfer and bioavailability of hydrophobic organic compounds (HOCs) in soil-water systems are greatly affected by their sorption process, and soil/water distribution coefficient (Kd) is a measurement of HOC sorption potential, thus it is very important to obtain the Kd of HOCs. Kd can be obtained by direct measurement (e.g., batch equilibrium method) or indirect prediction (e.g., linear free energy relationships). Both approaches have their respective advantages, and are used simu...