Water Pollution and its Control

This chapter focuses on the processes and control of pollutants in surface waters and in the sediments with which they are associated. It evaluates the common water treatment technologies available for the prevention of surface water pollution. As in the atmosphere, solar heating and the differences in temperature both laterally and vertically largely define the ocean circulation. Generally of more interest to the environmental engineer than the global circulation are local wind-driven flows. If there is a flat water surface with no horizontal pressure gradients or slope to the water surface, the only significant driving force for flow is the wind. Flow in streams is generally a balance between the gravity flow due to the slope of the water surface and friction at the sediment surface. The influence of surface waters on contaminants can be divided into either fate processes such as chemical degradation or equilibrium phase partitioning or transport processes such as mixing and vaporization.