Waste Water Treatment

The dirty water that comes homes and businesses as a result of laundry, using the bathroom and all the soapy water that comes from washing dishes, is what we called sewage or waste water. It is treated by a variety of methods to make it suitable for its intended use .water treatment is done in two main stages, Primary and Secondary treatment. In arid areas, where there is not enough water, sewage also undergoes tertiary treatment to meet the demand of drinking water supply. During primary treatment, the suspended particles area separated from the water and the BOD of the water is reduced, preparing it for the next stage in waste water treatment .Secondary treatment can be done by the variety of means .the most common methods are the Trickling filters and activated sludge. The activated sludge method uses air and a biological floc that is comprised of bacteria and protozoans. This aeration continues for 4 to 6 hours, after which it is stopped and the contents moved to a settling tank. In this tank, the floc settles out and removes much of the organic materials with it. This process removes 75 to 95 % of the BOD. In the tricking filters, sewage is passed over a bed of rocks or molded plastics .over which a bio film of aerobic micro-organisms grow. This method removes 80 to 85 % or BOD. The water is then disinfected, mostly by the chlorination, and released into flowing streams or oceans. The statistical analyses show that there were significant relationship among percent land cover, source water quality, and drinking water treatment cost. The data exhibited high variability and indicating possible uncounted constraining factor – such as in the diffrenceses in water treatment plant processes and hydrological, geological, and regional diffrenceses, which remain as future consideration.