Transcription
Hello there. You all have definitely heard of environmental pollution, and one of the types of environmental pollution is air pollution. Air pollution refers to the degradation of quality of air in a particular region due to the introduction of harmful materials, which we call as the pollutants.
Now, there are different causes for air pollution, like the domestic combustion. When we burn firewood or when we are burning fuel, whatever gases are getting released are toxic to the environment and they contain pollutants, and thus there is air pollution. This is mainly true in the rural areas. We also have industries contributing heavily to the air pollution, and we have vehicular pollution, which is also very, very rampant globally.
So, in this video, what we'll be looking at are the different ways of controlling air pollution. Of course, there are other causes as well. That is, the waste in landfills releases a lot of methane, which is a greenhouse gas, or the fumes from the paints which are applied indoor are also in a way adding pollutants to the air and causing air pollution. We also have crop waste burning, which is a big problem in certain areas because that again releases a lot of toxic materials into the air. Mining, construction activities, all of these are different sources of air pollution.
However, we will be looking at how to control air pollution from mainly these three sources: that is, due to the domestic combustion, what all can be done to avoid this or at least reduce it? What can we do to reduce the air pollution from industries? And what can be done to reduce the air pollution from vehicles? These are the three headings under which we'll be dealing with in this video.
Before we look at how to control air pollution, let us look at what are the effects that it has on the health of individuals and biodiversity, and what effects it has on the environment. Now, on the health, we know that air pollution causes a lot of respiratory diseases. There's coughing, continuous wheezing, asthmatic attacks. So, it causes, it affects our respiratory system. It also causes lung cancer, especially this is seen with women who use the chulha, where there is a lot of smoke that they are inhaling directly, and that smoke contains carcinogens or cancer-causing agents. So, it is known to cause lung cancer as well. Not only that, long-term use can lead to cataract and even eye irritation from the smoke that is coming in in the domestic setup. This is the health effects that it has.
Apart from that, we have a lot of effects on the environment as well. So, our biodiversity gets affected. There is global warming that is occurring due to the greenhouse gases. So, greenhouse gases are normally also present in our environment. They're helping to keep our environment, our atmosphere warm, but the problem here is there is too much of the greenhouse gas. So, the warmth, the heat in the environment is also very, very high. That's what we call as global warming, and then global warming has a host of other effects which leads to climate change.
There's smog problem, which happens in cities or areas where there's a lot of smoke that's coming up. Smog is a mixture of smoke and fog. This again can lead to a lot of health problems, a lot of detrimental effects in people, in the environment, on the buildings, or in, you know, with respect to the animals, the plants keep dying. So, smog also is a big problem that can happen to the environment.
Ozone depletion. This mainly happens due to certain components called as the chlorofluorocarbons or their derivatives, and these start depleting the ozone layer, which is there in the stratosphere. Stratosphere layer of our atmosphere contains ozone, which protects us from the ultraviolet radiation. So, what happens is these components start breaking down the ozone, and then there is nothing to protect us from the harmful UV rays of the sun.
Acid rain is yet another problem that mainly happens when we have a lot of sulfur oxides and nitrogen oxides in the atmosphere. So, these sulfur oxides and nitrogen oxides react with water, and then they come down in the form of rain, which is highly acidic. Now, what happens in the presence of acid? All the tissues get burned. So, the animals are harmed, the plants, you know, are harmed because all their leaves fall off, they are completely burnt out. It's very harmful to the skin of human beings. So, these are some of the effects that the, uh, air pollution has on the health of human beings as well as on the environment.
Now, let's look at what are the measures to combat air pollution or to reduce air pollution at the domestic level. How do we come out with the alternatives for domestic combustion? So, the first thing is we need to look for alternative fuel sources. Now, what is being used in the rural setup is mainly wood. So, fuel wood is being used. Of course, it has been reduced. A lot of work has happened in this in this regard, and they have reduced the usage of wood. However, in many areas, they are still using firewood too for all their domestic purposes, to burn anything, they are using firewood. Now, the problem is we need to replace this firewood or fuel wood with a clean fuel. Clean fuel is something that is, you know, it is not going to harm the environment. That's why it's called as a clean fuel. So, we need to go for clean cooking. We need to use clean fuels while cooking. We need to use energy efficient fuels while cooking, those which do not harm the environment but which serve our purpose as well. Those are the clean fuels.
So, there are different alternatives that are there. The first one is, instead of using firewood, using cow dung cakes, oil cakes, or pellets made of different variety of organic matter. These can be used instead of firewood. Anyway, these are amply available in the rural setup, so they are much cleaner in comparison to the firewood. Usage of solar cookers. Using solar energy, we can use solar energy to the, to pump or to channelize. We can convert that energy for the cooking purpose. So, solar cookers also can be used. Of course, they have certain disadvantages, but they are very, very clean. The sun's energy is highly clean energy, does not cause pollution to the environment.
Using kerosene as an alternative. This is definitely cleaner than using coal or wood. It's not fully eco-friendly, but it's better. So, converting into, you know, using kerosene as or kerosene lamps or any other kind of kerosene stoves can be used instead of burning firewood. And lastly, this is one of the most, um, efficient. It is one of the most feasible technologies that is available, which is very, very good in a rural setup. Because in a rural setup, in a rural area, we have a lot of cow dung that is being generated. We have a lot of agricultural waste that is coming from there, which can be used to generate biogas. So, biogas mainly comprises of methane, carbon dioxide, and certain small quantities of other gases as well. What happens over here is, in this tank, we put cow dung, organic matter, any vegetable waste, agricultural waste, any waste can be put into this container, into this tank. Add water over there to make a slurry, and then that slurry is allowed to be in this tank in a closed condition or in an anaerobic condition, where microorganisms work on it, and then we get the biogas. So, biogas comes out from here, and we can even take the waste that comes out from the outlet pipe, which can be used as manure. So, that sludge can be used as manure. This is a very good method to replace firewood in a domestic setup. These are some of the alternatives that we can have to fuel wood.
The next one is controlling air pollution from the industries. Now, in an industry, a lot of smoke is being released regularly. Every work in the industry will release a lot of, you know, exhaust which contains harmful gases, which contains a lot of suspended particulate matter. It's not only the toxic gases, it's not only sulfur oxides, nitrogen oxides, carbon monoxide, hydrocarbons. It's not just that, it also contains suspended particulate matter, which is abbreviated as SPM. Suspended particulate matter, you can think of it like dust, very fine particles, which when go inside our nose or into our respiratory tract, they go and cause a lot of problem in our lungs. So, industrial pollution and vehicular pollution, especially, is associated with suspended particulate matter as well.
Now, there have to be a lot of pollution control devices which should be used by industries. They are being used. Many industries have taken up these technological measures, which can, you know, remove the pollutants. Either they'll absorb the pollutants, or they filter out the pollutants, or they'll dilute the pollutants. These are in place in many industries, but we need to ensure that all industries should have this as a mandate.
So, let's look at some of the filters, some of the devices, technological measures which can be used that are helping to reduce the air pollution. The first one I have shown here is a cyclone filter. Cyclone filter, like the name says, it's a filter. So, cyclone filter or cyclone separator. What it does is, it creates a high-speed flow over here. You can see over here, it's like spinning at a very high speed. That spinning leads to the formation of centrifugal force, and due to that force, particles get collected at the bottom. So, the air comes in over here, the smoke from the exhaust from the industry comes in here, and then due to this high-speed spiral airflow that's created, that causes all the particles to settle down, whereas the clean air is taken out from the top. So, this is one example of a technological measure or a technological device that can be used to control pollution.
The next one we have here is an electrostatic precipitator. Electrostatic, think of it as, you know, something related to electricity. What we do here is, we pass the toxic gas, where we pass the smoke or whatever exhaust is coming, through a region that charges the particles. So, whatever particles are suspended in the gas, they get charged when we pass them through this highly ionized zone. Now, when they pass through this ionized zone, the particles take up the charge, and what we do is, here we have the, there are certain plates which are put up over here, metal plates, which are having opposite charge. Now, you all know opposite charges are attracted. So, these particles have a particular charge. For example, if they have a negative charge, and these plates have a positive charge, the moment this gas passes through these plates, the particles stick to the plates because they are having opposite charge. So, this is very efficient. It is very efficient even for separating the small-sized particles. So, you get now the clean gas outside, and these particles are removed at the bottom.
The third one that we have here is a bag filter. Bag filters are very simple devices. They are very commonly used. You would have seen these in cement plants and stone crushing units, in mining industry industries. It is very commonly used. Here we have a fabric bag. There's a cloth bag that is there to remove the particles from the dust-laden gas. So, what you can see over here are the, the filters that are present in the bag. These are, you know, they are permeable fabric. They are fabric or cloth which is having small pores in it. So, when the gas passes through it, the dust particles are retained on the bag, and you have the cleaner air that is coming out. These are the simplest ones, called as a bag filter.
The next one we have here is a gravity settling chamber. Here, it's not very efficient. It has low efficiency and compared to the other ones, but then it is very cheap, and that is why many industries employ this as well. So, what happens over here is, the gas which is containing the particles comes in through this inlet. The, there is, you know, there is the entire chamber slows down the gas flow so that the particles can settle down, and then the clean gas comes out over here. They are moved at a very slow velocity. The air is moving at a very slow speed, very less speed, so that the particles are able to settle down by gravity. But because it's only gravity that's in place over here, this process is not very efficient.
The last one we have here is a wet scrubber. Wet scrubber, or it's also called as a packed bed wet scrubber. What we do here is, we mix a scrubbing liquid, usually it's water. So, we mix a scrubbing liquid. You can see over here, the water is coming in over here. We have the gas coming in over here. So, the gas and the liquid are getting mixed with each other so that the pollutants are absorbed over here. Now, there is what is present in the middle. There is a packed bed. Packed bed, meaning there are small beads of some non-reactive material, a material which is not going to react either with the gas or with the water. So, there are beads over here. When we mix the water and the gas together, the pollutants, the suspended particulate matter will get absorbed onto this packed material, onto this bed. Now, once it is absorbed onto the bed, you can take the clean gas outside. So, that, you know, the clean gas comes out from the top, and the contaminants are taken out from here. This is specially done for acidic gases. Whenever the industries are generating acidic gases, they do this, and what they do here is, instead of water, they use lime water. So, when lime water mixes with the gas, it neutralizes the components, and the pollutants can be absorbed over here. So, these are some of the devices that can be used to control industrial air pollution.
Apart from this, apart from the technological devices, we need to also look for energy efficient devices to save energy. So, one simple example is, you know, industries generate their own electricity, and then that electricity when it is being generated, there is heat coming out, which they use for other processes in the industry, for example, for heating or for processing the steam. So, what they are getting as a byproduct, they are using it for some other process in the energy, in the industry, which makes it energy efficient. Another example I can give you is where we have very advanced or, you know, very modern boilers and furnaces which can take the entire process to a much higher temperature, but with very less fuel. So, a lot of work is happening in this. Not only that, maintaining and repairing the instruments at all times ensures that it saves energy. Using efficient lighting, for example, LED, or using sensors to turn the lights on and off. Example, in a bathroom, you don't need the lights to be on the bathroom throughout the time. So, you attach a sensor over there, the moment someone walks in, there is motion, and then the light turns on. These are all simple technologies that can be used, simple measures that can be taken to ensure that there is energy efficiency in an industry. That reduces the air pollution, actually.
We also have clean technology that is to be utilized. So, we should not, you know, we should not depend too much on non-renewable sources like coal or fossil fuels. Instead, we should promote the renewable energy sources like wind energy or solar energy or water hydropower. All of these are clean resources. Or we should go for recycling of things. We can use green transportation inside the industry. How do we use green transportation? Using an electric vehicle to move around inside the industry, or using cycles. If it's a very big industry, you need to travel from one end to the other, instead of using cars or buses inside, use cycles. So, these are all examples of clean technology which can be adopted to reduce air pollution.
Meteorological control. Meteorological control is basically, you know, meteorological conditions are the local weather patterns. So, how much the pollutant is going to concentrate or accumulate in a particular area is definitely based on the weather conditions, on the meteorology. So, you need to ensure that you study the weather patterns of an area. That also will help us to control the air pollution. For example, if a particular region is having a lot of, you know, calm air, then the pollutants will not move around, they'll not disperse, they'll all settle in at a particular in that region as itself. Or what you can do is, you can identify the source of the pollutant by using the weather data. You can predict the air pollution event. For example, inversion can be predicted. Inversion is one type of event, we'll not get into the details of it over here. You can even use computer models to predict the air quality. If you set up this industry in this region, then the air quality will move from this to this. All of that can be done if you study the weather patterns of a particular area. So, whenever a new industry is set up, you need to make sure that it is following all these, you know, all these points as well. All of these measures are also taken into place. For example, the smoke that comes out of an industry should not move towards the city. So, we need to ensure the exhaust pipe is in such a manner that it is not putting the smoke towards the industry, or, you know, it does not release too much smoke in case of cold conditions because it causes smog, like I told you earlier. So, these are all the basic things that we should know the weather patterns of a particular region before we set up an industry because weather definitely affects how much the pollutant is going to concentrate in a particular region.
Lastly, we have something called a zoning strategy. Zoning strategy is like making zones. So, setting aside different areas for industry, so that the industrial area is away from the residential area, or in, in between the residential area and industrial area, having a green belt. In fact, one example is in Bangalore. There are three zones of industry: one is the light zone, one is the medium zone, one is the heavy zone. Means, only industry is in the light industry category should be in the light zone. Heavy zone should have only the heavy industry category. Why have they divided this? Thinking of the city. So, heavy industries are all away from the city, so that too much of pollution does not enter the city and does not enter the residential areas. And in fact, in Bangalore, very large industries are not even permitted because they will cause too much pollution. The weather of Bangalore is such that it is very cold. So, too much of air pollution if it comes in from the industry, it will not get dispersed. So, you can see over here how the planning authorities have made sure that, seeing the weather conditions, zones have been created. And there are penalties also if the, they do not follow the laws by the government. If they do not follow the central Pollution Control Board norms, then they will definitely have to pay the, pay up the penalties. That is also there in all, in all the cities globally. This is there. So, the government will put up some fine, or it may cancel your license, it may even imprison you, put you in jail if you do not follow the norms.
Taj trapezium zone. So, this is one example of a zoning strategy. Now, you all might have heard of this wherein it was realized that Taj Mahal, that is the, you know, the monument Taj Mahal was getting affected from the smoke that was coming from the oil refinery that is Mathura oil refinery was releasing a lot of smoke that contains sulfur. And sulfur when it mixes with water, comes down in the form of acid rain. Not only that, it also starts corroding the marble, that is, it starts eating up the marble. Now, that acid rain was causing yellowing of the marble, it was causing cracking, it was causing chipping. So, they, this was brought to the attention of the authorities, and then in 1996, they came up with the Taj Trapezium Zone. Taj Trapezium Zone is a huge area, an area of 10,400 square kilometers, which is in the form of a trapezoid. You can see here, that's why it's called as Taj Trapezium Zone, also abbreviated as TTZ. Now, this zone contains three heritage sites. It's mostly in Uttar Pradesh, but a bit of Rajasthan is also there, and it contains three sites and more than 40 protected monuments. So, it contains Taj Mahal, it contains Agra Fort, and it contains Fatehpur. Now, what is the point of the zone? So, in this zone, you cannot have industries using coke or coal. Instead, they have to shift to natural gas. If they cannot shift to natural gas, then either that industry has to move out of the zone, or it has to shut down. So, it was made sure that the industries in this region do not produce anything that is going to affect the Taj Mahal. It was basically done to protect the Taj Mahal from pollution, to improve the environment around that entire region. That is why they have found in the form of a trapezoid, and this has been hugely successful. In fact, if you all have visited Taj Mahal in the recent times, they even have a lot of electric vehicles that are plying in the vicinity to reduce the smoke as much as possible. This is about the Taj Trapezium Zone.
Lastly, let us look at the use of vehicular, how, how do we reduce pollution from vehicles? Now, vehicles release a lot of sulfur dioxides, nitrogen oxides, volatile organic compounds. You might have seen this as VOC. Volatile organic compounds are very common from vehicular smoke, and that leads to smog and acid rain and all of the other problems that I told you earlier. High pollution, in fact, vehicular pollution is one of the biggest challenges globally. So, what can we do to reduce the vehicular pollution? There are different strategies that we can take.
The first one is to modify the engine design. You change the engine. Okay, I'm not saying don't use vehicles, but change the engine. Come up with a better idea, that is a cleaner idea for ensuring that there is less air pollution. So, modifying the engine design can be done by either using a catalytic converter or using a four-stroke engine as well. There are other technologies also in place, but let's look at these two basic ones. Catalytic converter is like a component that takes in the engine emissions, takes in the toxic gases. It has a catalyst inside, either platinum or palladium, and that helps to convert these toxic gases into harmless compounds. So, hydrocarbons are, this is hydrocarbon. Hydrocarbons are converted into carbon dioxide and water, or carbon monoxide is converted into carbon dioxide, or we have the nitrogenous compounds which are being converted into nitrogen gas and oxygen. So, in this way, whatever was toxic to the environment is being converted into a harmless compound. We can also have a four-stroke engine. Four-stroke engine is an internal combustion engine which has four piston strokes that you can see over here. What is the difference over here between a four-stroke and a two-stroke? Two-stroke is less efficient because in a four-stroke, fuel is consumed every once every four strokes. In a two-stroke, that doesn't happen. Here you have, there is more fuel efficiency because for every four strokes, only the fuel is getting consumed. So, you are consuming less fuel. You don't need to use an oil or lubricant in a four-stroke engine. So, these are all small changes that can be done to ensure that the air pollution reduces.
We can also go for clean fuels. This is a huge thing. A lot of research is being done on this. You would have seen a lot of electric vehicles in and around your neighborhood. So, clean fuels or alternate fuels is very important. Any alternate to fossil fuel, anything that can be used. Natural, for example, the natural gas, that is the CNG. Compressed natural gas. We know that CNG has been, you know, used in all the public vehicles of Delhi as well. So, compressed natural gas is one option, or going for biohydrogen, or we go for electricity. So, we, you know, we have hybrid electric vehicles, we have pure electric vehicles as well, and we have hybrid electric vehicles. Hybrid electric vehicles use electricity plus the regular fuel. So, they improve the usage of the fuel over there. We also have biofuels, for example, gas or Hall. What is the meaning of a biofuel? Fuel that you are producing from the, uh, natural components. Here, in this case, it is produced from crops. So, crops produce that ethanol. That ethanol is mixed along with regular fuel. This is very, very common in Brazil. So, these are all examples of options that we can have or clean fuels that we can use instead of the regular fossil fuel like petrol or diesel, which are very, very harmful to the environment.
We can also go for improving the public transport. So, public transport reduces 95% of the carbon monoxide that is per passenger. So, it's very, very important that we use more of public transport. We have, in fact, trains are more efficient. So, a large number of people can be transported in a train at a time. It saves fuel, it causes less traffic congestion, it causes, you know, less of greenhouse gases are being released. So, public transport has to be promoted in every city. To promote public transport, you need to make sure that there is public transport everywhere. See, what happens in many places, public transport is only in a particular stretch. So, people end up using their own private vehicles. So, government needs to improve the public transport system so that people choose this instead of their own vehicles.
Traffic management. Traffic management is, you know, making sure there is less congestion. Or what happens is, when there's a traffic pileup, when there's a signal or a pileup, it increases the vehicle emission. So, making sure the traffic is moving smoothly, for example, employing bus lanes or cyclist lanes for making sure that those people who are on those, especially a bus, it's a high occupancy vehicle, many people can be fit into the bus at a time. So, providing such lanes will help to make sure that people are able to reach faster and there's no traffic pileup. There is time restriction in many cities. This is there. Trucks or other commercial vehicles are not allowed into the city in the morning hours, or they need to use bypass roads, external ring roads, they should use instead of the city road. This is all to make sure that there is no traffic pileup. The facilities are provided for pedestrians, for cyclists, so that they are away from the motorized traffic. All of these will improve the signalization, it will improve the intersection, so that traffic pileup does not happen. That is our only aim over here.
We also have economic policy measures that have to be taken by the government. So, the government is putting less tax and duty for fuel-efficient vehicles. Those who buy fuel-efficient vehicles have to pay less tax. This is all a measure put in by the government to encourage people to buy such vehicles. Or, you know, more license fee and tax is applied on older vehicles because they do not conform to the current environmental laws. There's less tax on fuels like the compressed natural gas. So, people will be, you know, it's like an incentive. They'll want to use CNG, which is good for the environment. Mandatory use of low, low polluting or non-polluting vehicles, especially in government fleet. This has been taken up in Delhi. They have told that every bus needs to have compressed natural gas as the fuel. So, these are all the difference in taxation is very important for making sure that people are encouraged to use these cleaner fuels or cleaner technologies.
In fact, since 2000, we are having Euro norms which are being followed in India. You can see over here, Euro norms are being followed in India under the name of Bharat Stage Emission Standards, that is BS standards. You would have seen this on the vehicles. They have stickers for this. So, these standards currently, all new vehicles have to be BS6 standard compliant. But what is being used is BS3 and 4. 4 is in use since 2017. So, these are standards which are applied for the vehicles, how clean they are, how, how fuel-efficient they are, all of that is being employed. This is set up by the Central Pollution Control Board. So, these are the different measures that can be taken to reduce air pollution from domestic congestion, to reduce air pollution from industries, using a lot of technological devices, energy efficient devices, using meteorological control, zoning strategy. We can ensure that there is less air pollution from industries and from vehicles by modifying the engine design, by using cleaner fuels, by promoting public transport, ensuring that the traffic management is done well, and bringing in economic measures in the policy so that people are also encouraged to go for fuel-efficient vehicles.
I hope this video was useful for all of you. Hope to see you all in the next one as well. Thank you.