Science of Water : Concepts and Applications

10
Water Treatment Calculations
Gupta (1997) points out that because of huge volume and fl ow conditions the quality of natural
water cannot be modifi ed signifi cantly within the body of water. Consequently, the quality control
approach is directed to the water withdrawn from a source for a specifi c use. The drawn water is
treated prior to use.
INTRODUCTION
In the following sections we present the basic often-used daily operational calculations along with
engineering calculations used for solving more complex computations. This presentation method is
in contrast to the presentation methods used in typical water mathematics texts. The author deviates
from the norm based on and because of practical real-world experience; that is, experience demonstrates
that the environmental engineer tasked with managing a water or wastewater treatment plant
is not only responsible for computation of many complex math operations (engineering calculations)
but also for overseeing proper plant operation (including math operations at the operator level).
Obviously, engineers are well versed in basic math operations; however, they often need to refer
to example plant operation calculations in a variety of texts. In this text, the format used, though
unconventional, is designed to provide both basic operations math and more complex engineering
math in “one” ready format.
WATER SOURCE AND STORAGE CALCULATIONS
Approximately 40 million cubic miles of water cover or are found within the Earth. The oceans contain
about 97% of all water on the Earth. The other 3% is fresh water: (1) snow and ice on the surface
of the Earth contain about 2.25% of the water; (2) usable groundwater is approximately 0.3%; and
(3) surface fresh water is