ABSTRACT
The elds of science and engineering encompass many diverse elds of activity. It is therefore important that means be available to place widely scattered information, particularly of an environmental nature, in the hands of environmental specialists (Theodore 2014). One need only examine the earlier chapters to appreciate the need for the ready availability of a vast variety of information. Such problems are almost always approached by checking on and reviewing all sources of information. Most of this information can be classied in the following source categories:
• Traditional • Chemical engineering • New • Personal experience
Each topic is discussed in the sections that follow.
