 Hello everyone, I am Swati Gargay, Assistant Professor, Department of Civil Engineering from WIT, Solapur. Topic for today's session, Water Treatment System. Learning outcome of this session, at the end of this session, learner will be able to explain water treatment process. This is a simple line diagram of water treatment process. First, water is collected from the natural source of water, say river, or some reservoir is constructed near the river, through that water is collected, then that raw water is stored in a water treatment plant, then after treatment that water is stored in an elevated service reservoir, elevated service reservoir is nothing but the water tank, then after sufficient storage of water, water is distributed in a distribution network. So, we will see in detail what are the units in water treatment plant, how it is treated there. So, these are the units of water treatment plant, first the water is collected from the river intake, then it is sent to the water treatment plant by constructing some jack well, then after treatment water is stored in a elevated service reservoir and then it is distributed. So, we will see in detail what are the units of water treatment plant, so that in the box all the units of water treatment plant are there. The first unit is a screen chamber, in the screen chamber all the floating insoluble materials, say water bottle, plastic bag or any other large material removed from the water. So, this is the pre-treatment and after that water sent for the aeration. In the aeration water and oxygen comes in close contact, so that water is purified, then after purification some coagulant agent will be added in a water. Alum is the best example of coagulant agent, due to that all the tiny dust particle in water sample stick together and it is forming a flow in the water, flow is nothing but the large or heavy dust particle forming in the water sample. So, after flocculation that heavy dust particle should be settled down at the bottom, so that it is sent in the sedimentation tank. In the sedimentation tank flow settled down at the bottom, so that water sent here slowly, so that it gets sufficient time to settle down at the bottom and it settled down due to gravity and after settlement it removed from the bottom of the tank. Then water is sent for the filtration, filtration it is the layer of sand and gravel through that water filters and that filtered water go for the chlorination, chlorination is nothing but the disinfection, so the chlorine is added in a water to remove some pathogenic bacteria or to prevent water bond diseases. Then that clear water store in a elevated service reservoir, after sufficient storage water is distributed in a distribution network, so this is the line diagram or this is the flow chart of water treatment plant. This is the alternate flow chart of water treatment plant, so that it is more clear what is flocculation, what is sedimentation to you. See here there is a raw water, after screening and after aeration coagulant agent will be added in the water and after addition of coagulant agent some flow formation will be start, so that black dots showing the flow formation and all the small dust particles stick together and forming a large and heavy particles. This process is called as the flocculation and then it has to settle down at the bottom, so for that it is sent in the sedimentation tank, so in the sedimentation tank all the heavy particles are settling down at the bottom of the tank. Then clear water is sent for the filtration, see filtration it is the layer of sand and gravel, so through that water filters and here we get the filter water and after some doges of chlorine it is stored in the tank and after sufficient storage water is distributed, so it is showing that it is supply to the house. So we have seen the flow chart and we have seen the some alternate flow chart also, now we will see the theoretical definition of that unit, so first unit is screening chamber, so first unit is screen chamber, so screening chamber it is a first unit operation of water treatment plant that separate large floating material from the water. Second unit is aeration, it is a physical process which bring water and oxygen in close contact in order to remove dissolved gases, dissolved gases say CO2, H2S, CH4, etc. Then third flocculation, it is the process in which tiny particle of dirt in water stick together to form flocs in water, so that formation of flocs is called as the flocculation, sedimentation it is the physical water treatment process which removes suspended solid from water with the help of gravity. These are the some images of units of water treatment plant, this is the intake tower installed in a river, so raw water is collected from the source of water showing in the image, after that it is sent to the water treatment plant, so first unit in a water treatment plant is a screen chamber, so there is a screen which remove large floating material or some insoluble material, this is a picture of mechanical aeration, machine is rotating the water, so that all the surrounding air getting mixed in the water and it get oxygen and it get purifies, this is a image of cascade aeration, water is flowing from the steps, water is flowing over the steps, so that it get sufficient time to mix oxygen in a water, this is a multi tray aeration, from one tray to another tray water is passing and while passing the air getting mixed in the water, there are many types of aeration but few of them I have covered in this session, now you pause video here and answer the question which is the correct flow of water treatment plant, in the option there are four flow chart, you select the correct flow chart of water treatment plant, first option is the correct option, firstly the water enter in a screen chamber, then it goes for the aeration, after aeration is go in the sedimentation tank and after sedimentation filtration is there and after filtration we get a clear water, so this is the correct flow of water treatment plant, after aeration some coagulant agent say alum is added in the water and it form and it cause the flow formation in the water that flow has to settle down at the bottom, so that water is sent in the sedimentation tank with the slow rate of flow, so that due to gravity all the heavy particle will settle down at the bottom showing in the image and this is the picture of sedimentation tank, this is a image of circular sedimentation tank, after sedimentation water is sent for the filtration, see here the dirty water is there and after filtration we will get the clear water, then after filtration some chlorine dosage will be given to water and then that clear drinkable water stored in a water tank and after sufficient storage it is supplied to house to house, these are my references for this video, thank you very much for watching.