Wastewater Treatment and the Role of Laboratory Professionals.
Abstract
Wastewater Treatment combines biological, Chemical, and physical unit processes to purity large volumes of sewage. Each unit processes of based on a naturally occurring processes-targets contaminants in a unique way. By analyzing wastewater constituents at various stages of treatment. Laboratory professionals play a vital role in the efficient operation of wastewater treatment plants and, thus, help to protect the environment and public health.
This is the second article in a 3-part continuing education series on waste. Upon completion of this article the reader will be able to describe the basic processes used at wastewater treatment facilities prior to discharge of treated wastewater into a stream or river.
Few of us realize what happens to wastewater after we flush it down the drain. We know that a network of pipes under our streets eventually leads to a wastewater treatment facility; but how does a wastewater treatment facility work, and what happens to the water?
When wastewater is introduced into stream naturally occurring microorganism consume the organic waste material. The result is a decrease in the dissolve oxygen concentration caused by microbial respiration in the stream. Re-aeration the natural transfer of oxygen. Between the air and lipid replaces the oxygen. But depending on the difference between the volumes of wastewater and stream oxygen may not be replaced quickly enough to overcome the depletion. If it is not the stream may become deoxygenated suffocating the aquatic organism.
Wastewater Treatment
The first underground drains or sewers were constructed by the Romans to provide a means to remove rainwater. Human waste, however was exclude from sewers until the late 19th century, when scientists discovered that contaminated water was related to the rapid spread of disease during the great epidemics.
Even then human waste transported in sewers was still not treated before it was discharged into streams. This resulted in aesthetic, health, and environmental problems because the uncontrolled discharge of wastewater surpassed the natural ability of waterways to maintain their purity. It was not until Koch and Pasteur announced their germ theory that wastewater treatment facilities came into being.
With the goal to improve water quality, modern wastewater treatment facilities take advantage of biological, chemical, and physical principles to accelerate natural processes under controlled conditions. Such treatment methods are known as unit processes. A typical plant uses many unit processes to remove specific contaminants before it discharge the treated water into waterway. A diagram of a typical treatment facility is presented in Figure 1.