CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Water is a universal liquid that sustains being and all other lives. In fact that body is known to contain a lot of water and covers about 60% of the total land surface. The first form of life was believed to have started from water millions of year ago and up till now no living things can exist without it. Water is one of the most common solvents and exists in gaseous, liquid and solid state (Ababio 1990).
Hence, there are so many ways in which water is useful to human being. It can be used for drinking purpose, which is the most important use of water, it may be used for domestic purpose such as bathing, washing, cleaning etc. in manufacturing industries and in Agriculture etc. Therefore, the important of water cannot be overemphasized in the community (Encyclopedia Britain 1970).
Different type of natural water exist on earth’s surface which include; rain water, spring water, river, lake water and sea water etc. rain water is considered as the purest from all natural water because it is formal as a result of the condensation of water vapour in the atmosphere.
Spring water on the other hand emerges at the base of sloppy ground where the surface elevation is below the water table, in an aquifer from where the water can escape (Fawole 1980).
;However, water that contains few microbes may be considered good as longs as pathogen and inquiries chemicals are absent. Nevertheless the quality of water is determined by the types and quality of microbes present in it. Some natural water could contain some microbes and still be good for use. Generally contaminants that can be found in water include, microorganisms such as bacterial, algae, protozoams, fungi, etc.
Some water are used in household, factories etc which are considered as waste water. Biologically these waste water can be treated and be used again. Biological waste water treatment is the common method used to treat water before it is discharge to the communities.
Biological waste water treatment system consist of series of reaction vessels which are designed with the optimum mixing energy, retention time, and nutrient addition to provide an optimum environment for biological avidity resulting in removal of nitrates heavy metals, ammonia, and biochemically oxidizable organic mixture as the biochemical oxygen demand (BOD).
More so, Thomas E, Schultz (us filter) explain that the use of bacteria and other microorganism to remove contaminants by assimilating them has long been a mainstay of waste in the chemical process industries (CPI) because they are effective and widely used. When considering biological waste water treatment for a particular application. Thomas says, it is important to understand the source of the waste water generated, typical waste water composition discharge requirement events and practices withing a facility that can affect the quality and quantity of the waste water and pretreatment ramification consideration of these factor will allow you to maximize the benefit of your plant gains from effective biological treatment.