Waste Water Treatment Process

1211 Words5 Pages
People often think that sewage is the only component in wastewater. As a matter of fact, all the water used in the household which then goes down into the drains is wastewater. Water from showers, sinks, dishwashers, washing machines, and toilets are examples of wastewater as well. Today’s wastewater treatment plants are designed to provide water continuously. At the wastewater treatment plants, the water that has been used is treated before it is allowed to be returned to the environment. This is to remove the contaminants present in the water and also to improve the quality of water to an acceptable level. Water-borne diseases would be widely spread if the contaminants are left untreated since they are directly discharge to the river, lake…show more content…
Unlike biological and physical water treatment process, it uses chemicals to remove contamination from water. Chemical water treatment process can be divided into two processes: Coagulation-flocculation and disinfection process. Coagulation-flocculation process is a pre-treatment process before biological treatment (Amuda & Amoo, 2007). The main purpose of coagulation-flocculation process is to eliminate suspended solids and organic material in water. The coagulation process helps to weaken the negative charge in the particles. This results in the initial aggregation of colloidal and fine suspended solids to form microflocs. Flocculation is a process that combines the microflocs to form larger agglomerations which later can be removed through sedimentation and filtration (Ebeling, Sibrell, Oyden & Summerfelt, 2003). The commonly used coagulation and flocculation aids are alum, ferric chloride, ferric sulphate, ferrous sulphate and lime. Disinfection process is a selective destruction of disease-causing organisms in water supply. Disinfection is used to destroy harmful organisms such as bacteria and viruses and removes the odor precursors (Jiang & Lloyd, 2002). The common disinfectants used are chlorine, sodium hypochlorite, chlorine dioxide and ozone. There are three common process in disinfection process; chlorination, ozonation and UV light. Among these three processes, chlorination is the most common process that has been applied in many industrial and domestic wastewaters. The common chemicals used in chlorination are chlorine gas and hypochlorite solutions. In this procedure, the water usually chlorinated just before discharged to ensure disinfection and no excess chlorine inside the water. On the other hand, ozonation is a process that destroys bacteria and microorganisms through infusion of ozone. Ozone is use because it is a strong oxidizing agent and able to remove viruses due

More about Waste Water Treatment Process

Open Document