Primary Treatment Of Waste Water Case Study

“Primary Treatment of wastewater consists of the removal of insoluble matter such as grit, grease, and scum from water.” (Manahan, 2010) The first step of this treatment involves screening which prevents large solids from getting into the treatment process. This is followed by an oil and grease trap in which oil skimmers are used to separate oil and grease from the effluent. The separated oil and grease are then given to recyclers. From this the water is transferred to the collection tank and from there it goes into the equalization tank where the pH of the water is to be maintained at 7. From the equalization tank the water is pumped into the flask mixture which has got stirrers that works at approximately 1395 rpm. Then the water moves into
The COD of the water is considered to get reduced to a great extent due to chemical neutralization process within the water treatment plant itself.
Secondary treatment is designed to reduce the Biological Oxygen demand of the water and removes 90% of BOD and 90% Suspended Solids. In the plant this is done aerobically with the help of microorganism which in the presence of oxygen degrade the organic matter present in the waste water till the BOD value reaches the acceptable level. This process is known as the activated sludge process this treatment removes. The required bacteria for this process are being grown in a controlled manner by adding M aqua culture .In the first aeration tank diffused aerators are used aerobic digestion of organic matter by the microorganism and urea , DAP is added in all the
From this the water goes into aeration tank 2 and aeration tank 3 which are being utilized to provide greater efficiency to the ETP .Then the water goes into the secondary clarifier where Alum and Polyelectrolyte are added for the disruption and settling of the culture and the sludge produced from the secondary clarifier is transferred to the sludge filter press / sludge drying bed while in the water 1-3 ppm chlorine is added as a disinfectant and then it goes into the Activated carbon filter which is a dual media-filter having gravel , sand and carbon . The purpose of this carbon filter is dechlorination and to remove color and odor from the water. The final treated water is then passes through a fish pond to ensure that the water will not harm the aquatic life and is then discharged through the drains. The sludge from the filter press is then given to Recyclers. In some plants dechlorination is done by adding Sodium Meta bisulphate. For the sewage treatment plants have built a separate Sewage treatment plant. Both inlet and outlet parameters are being tested daily in the plant to check the efficiency of the ETP. Further every quarterly all the parameters are being tested by the water testing agency as per