Process Block Diagram - continued.

Block diagrams represent key components of a process. Usually block diagrams go from left to right. To read a block diagram, start where the process begins. Then follow along the blocks and see how the process progresses. The equipment is shown as "blocks" with identification labels. The fluids are shown as arrows with descriptive notations.

This block diagram shows wastewater treatment cycle. To start with you identify a logical starting point and then work your way through the process. In this particular case, we start from the points where wastewater is generated (shown as two sources), and then you present rest of the process blocks in a logical order.