ABSTRACT
Wastewater treatment is essentially a combination of physical, chemical, and biological processes. With the exception of the addition of chemicals such as alum, ferric chloride, chlorine, and others, what happens in a wastewater treatment plant is basically the same as what goes on naturally in a stream (the stream self-purification process). The wastewater treatment plant simply speeds up the natural processes (under controlled conditions) by which wastewater purifies itself.
