 Let us go for some few more examples of the definitions of the ways. So ways from commercial or trade companies which due to their nature composition or quantities are especially hazardous to human health, air or water or are explosive, flammable or may cause diseases. This is another definition which is given by some organization. If you look at this definition hazardous ways are those ways which due to their nature and quantity are potentially hazardous to human health and or the environment. Everybody talks about the human health and environment and require special disposal techniques to eliminate or reduce the hazard, alright. So this is the attribute of the system. Another definition of the ways is one that may cause or significantly contribute to serious illness or death or that poses a substantial threat to human health or the environment when improperly managed, very simple definition. A lot of message is given over there. Waste is any substance for which the owner or the generator has no further use and which is discarded. But I am sure you will agree now this definition is totally dislodged, it is totally you know uncontemporary, it is obsolete, why? Yes, so the whole idea is to not write this type of statement. The whole idea is to synthesize the material, understand its property and then say yes this material can be utilized and that is what the contemporary thought processes. To the types of waste, these are two categories of the waste, non-hazardous waste and hazardous waste, very wide categories. And in non-hazardous waste we have municipal waste and this could be industrial non-hazardous waste also. However, in hazardous waste normally we talk about industrial waste. Another question is how do you define an industry, that is an interesting question nowadays. Whether R&D is an industry or not, whether education has become an industry or not, you agree? So these are the questions which are contemporary and you know you have to answer and you have to classify them the way you can in one of these situations. There is a very interesting act which is available, you should read this and this is what is known as RCRA, I do not know whether you have come across this or not, Resource Conservation and Recovery Act. So how to conserve the resources? For making concrete, you require sands, you require gravels, you require aggregate, you require cement, cement itself is coming out of the natural resources. So truly speaking creation of cement and concrete is not a green solution, agreed? Because you are emitting a lot of carbon dioxide in environment. Now the question is how to recover and how to you know conserve the resources which I am trying to utilize. So one of the ways would be you know people talk about completion of the cycle of sustainability. So whatever I am digging out of the ground if after the process is complete and if I can put the residues back into the soil, the sustainability is done. So if you go through the papers which my earlier students have written particularly Pradyusha and she has talked about you know what is sustainability and why we should be marrying different types of waste with each other to create some useful material. So these type of philosophies people are trying to work on. So read the papers by J. V. P. Pradyusha, J. N. T. Pradyusha, she has written 2-3 papers on sustainability issues associated with the waste and the conservation and of course now this batch of students is also working this area. If you see the paper which has been written by Rakshit on utilization of dredged sediments and this was a publication 2-3 years back, you can check out all these publications on my website and you can download them and you should educate yourself to see where the profession is heading to. So Rakshit talks about the application of dredged sediments. So coming to the municipal waste, the list is not so big. Mostly the municipal waste are compost, compost could be pathogenic, it might be having microbial aspects associated with it, scrap tires. So the more and more automobiles you have in the city, you buy a car and normally the dictate from the company is after 6 months you should do tire rotation and you should replace the tires and so on. So the more and more number of automobiles you have in the city or the country, what is the big challenge? You have, you are producing more and more scrap tires. So though on one side this is a symbol of status as well as the strength of the country and the prosperity and GDP is going up, but the second side what is happening? So the more and more automobiles you have, their engines have to be fine tuned, engine oil has to be changed, where it is going to be disposed, nobody has any idea, clear? And how these scrap tires should be utilized is a big issue, used oil, so used oil is a good example of the oil which is coming out of the engines of the automobiles, lubricants and transformers because oils are dielectric material. So oils have a certain life, once you want to replace the spent oil, used oil, burnt oil, what do you have to do, you have to do a complete process to clean it, alright? The way kidney cleans up your blood in the body. So the question is where to dump this used oil and how to rejuvenate it, how to reuse it and so on, sea based sludge. I think we have discussed a lot about this, the bio, you know solids which we have generated and we have too less, now how to deal with the bio solids because these bio solids are pathogenic in nature and hence you cannot use them even fertilizer as a fertilizer, you cannot spread them on the top of the surface of the earth and so on. Water treatment sludge, I think I have discussed all these things earlier if you remember. So whatever treatment process you follow, either the water which is drinking water or the sludge, you are going to produce sediments which would require a special treatment. So this is where I had suggested you to read the papers which are written by Sushmita Sharma, you remember? I had talked about SEGS, socio-economically generated sediments. So read her papers and you will realize that what is that we are trying to talk about. But the list of industrial non-hazardous waste is very big because this is a good sign also, you know that the country is flourishing, we have so many types of industrial activities going on in the country, very nice, so the more and more industrial activities, the more and more prosperity it should have brought, but unfortunately what is happening, the more and more industries, the more and more influence on the environment and contamination of the geo-environment and now the situation has become desperate, we do not know what to do, how to handle it. So coal ash, I am sure most of you are aware of, you must have worked on this as well, fly ash and bottom ash, we use 30 to 40% in making concrete fly ash, fly ash is also being used for making embankments, there are good examples where in India, I think I cited some examples also where the fly ash is being used as a embankment filled material, right now this type of works are going on the eastern part of the country close to Calcutta, if you ever get a chance to move from Calcutta towards Hyatt-Kharagpur, you will see lot of fly overs are being done where the soil is not being used, but the fly ash is being used as a filled material, by virtue of the properties of the fly ash and bottom ash that these are stable materials, they do not consolidate, they are granular material in the sense, silty sandy material easy to place though it flies off, but you cannot compact it is a big issue, but it is quite resembling and very close to the natural soil and it can be used. The second one is ferrous and nonferrous slag, different type of slag which are coming from industries, you know iron slags, blasphemy slag we call them copper slag, chromium slag, so these are the industries which are the muscle of the country, the more and more steel you produce, the country becomes more muscular, is this correct? But the issues are that the more and more steel you produce, the more and more slag also gets produced and now you do not have any answer where the slag should be disposed, one of the intelligent ways of using the slags would have been what people have earlier used is done is they have created PPC, Portland Pozolona cement clear, so this is where they blend the cement with the slag and you can use it, microfines is another good example of slags converted into microfine cements just by crushing it, pulverizing it, making it ultra fine, reclaim paving materials, so the more and more infrastructure is developing roads have been overhauled in the country everywhere, the question is that the top layer of the roads which is as faulted bituminous, after you are rehabilitating the entire road where would you dispose it? Because this is a source of leaching of carbon, so you must have noticed when the roads are done, normally they scrape the top surface and dispose the you know macadam in the vicinity itself, when rains come the chances are this carbon will leach through the ground water and it will contaminate the entire geosunit, so reclaim paving materials are also becoming a focus of you know discussion, construction and demolition debris, millions of tons of the CND waste is being generated and unfortunately it is either being dumped in the landfills or it is stacked somewhere alright, because we do not have designated places where the CND waste should be dumped, so this is becoming a big issue, there were some initiations by NGOs where they used to crush the CND waste, pulverize it and then they used to use it for you know alternate construction materials and this material has been shown to be quite good material for creating concrete of low grades, some of you might have also in this area where people are talking about you know recycled aggregates, so demolish the RCC structures and then try to retrieve the aggregates and recycle them, so this is where lot of efforts have already been done both in our country as well as abroad, cement and lime can dust alright, so this is a big issue, sulphates, where do you use sulphates, different type of acids which you are manufacturing alright, different type of fertilizers, foundry, ceramic, silica fumes, all these are good examples of non-hazardous industrial waste, dredged material, I think I talked about this, when you dredge the clays of the soils from the seabed, ocean bed or lakes or rivers, the problem is that this sediments have mostly high contents of organic matter and by virtue of this their water absorption capacity is very high, so the biggest problem is how to reduce the volume, where to stack them, what to do with them and truly speaking dredge material could be a good geomaterial, islands are being made out of it, so disposal is an issue, where are the designated bins, you understand bins dust bins, where are the designated places where the dredge material can be stored and how to reduce the volume, lot of research is being done in this area, so we were creating solar heated dredged sediments disposal systems, alright, so this will be the stack of the material which I can use tomorrow for creating some infrastructure, soils are prohibited, you cannot dig out the soil nowadays, I hope you are aware of this because of various court judgements and so on, so this seems to be a very interesting material for geotechnical engineers to sustain the infrastructure development, minerals of different types, waste rocks, mill tailings, coal refuse, washery rejects, phosphogepsum, so these are the processes by which you produce lot of mine tailings and the question is what to do with these mine tailings, what you should be doing is you should go to the web internet and check water waste rocks, alright, what are mine tailings, mill tailings, what are coal refuse, I will show you one example of a project which I dealt with as far as the washery rejects are concerned from the coal, coal is also washed, processed before you start selling it and using it, so I was involved with the project and I will show you today, phosphogepsum, you know when you produce urea fertilizers, the phosphogepsum gets produced as a byproduct, now the question is what to do with the phosphogepsum, so as the name suggests this is having lot of phosphorus in it, alright and then can this pH be neutralized by using some other material and can we create a composite which becomes a construction material would be interesting question, agricultural waste, we have talked about this, animal manure, crop left outs, wood which is lying in the field, these are good examples of industrial non hazardous waste, then comes the series of organic and liquid waste, different type of waste in the liquid form and the organic form, what to do with them, where to store them, how to dispose them, even the liquids which are coming in the form of the leachates from the landfills, a big question is what to do with those leachates, where to dispose them, different types of combustion residues, some people say that MSW should be combusted and big question is if I combusted incinerated at very high temperature, whatever residues will be created the ash, it might also be having toxicity, so what I am supposed to do with the ash, where should I dispose it, so that becomes a secondary source of contamination and so on, plastics is a big issue in the contemporary society and this is where Goli is trying to work on utilizing the plastic which is coming out of the municipal solid waste and marrying them with industrial byproducts to create interesting composites which would be a you know a big game changer in the infrastructure industry. So, our idea is to create components which are required for infrastructure development by using these type of you know industrial and domestic waste and create something interesting out of it. Government of India has a special mission on this, how to minimize the waste and they are encouraging lot of startups also in this, there is something known as AGNI Agni and this is initiative which is taken up by the government of India and check it out what these guys are doing and where the focus is Agni, AGNI and then the waste class, so the more and more industrial development takes place, more and more society you know attains wealth becomes more affluent, you know one of the ways of judging the affluence of the society is the amount of glass which is discarded, you agree with this, so this is directly proportional to the affluence of the society, so glass is used everywhere alright, different type of beverages, different type of drinks, different type of waters and different type of containers and so on. So, the more and more glass if society produces, it is understood that they are affluent, they are very interesting philosophy and now you have to work on this philosophy to produce guidelines and see what can be done and what is being done I will show you. So, disposal of industrial non hazardous waste is a big question, mostly people dispose of waste on the ground, big stacks which we have been talking about alright, it has one issues we have discussed about this in the previous lectures, so when rains come the water will start sipping through it and ultimately it contaminates the NGO environment, the stability of these types of stacks itself is an issue under static conditions and earthquake conditions both, how high I should be going, how much base width these stacks will be occupying footprint of the stacks is a big question, so land disposal has its own pros and cons, you might be disposing the waste which is likely to become airborne, ashes, red muds alright, so it is a big havoc, so the moment you dispose it if it flies off becomes airborne, the society gets affected, you will be surprised to know that guidelines are not available, what poor industries are going to do, whose job was to create guidelines and the code of practice, what again I am asking a question, what is central pollution control board, it is not chairs and tables, clear, what was my question, whose job it is ultimately the scientists, the policy makers, who should have come out with the policies of how to dispose the waste, what should be the modality, how much should be disposed in what manner, treat it or not, whether pretreatment is the must or not, after stacking what should be the policy further, how long I want to store it over there, is there a policy on this and if I do not follow any norms, ultimately what is going to happen, these stacks are rising every day and then the chances are that they may fall on your head, they may cause accidents alright, so now you can realize the whole thing, so this becomes a chicken egg story, even if I educate people to throw the garbage in the dustbin, ultimately where the garbage is going to go, chances are that it will end up in a landfill, so what I am supposed to do with this material, if it is non-degradable, are you realizing, so these are the issues, so as a nation what we should be doing and how we are supposed to take care of our waste is a big question, so the time has come when people like you should adopt this material as a manmade resource and create something out of it, is this okay, why to do excess mining, when I might be having resource in another form available by as an outcome of some human activity, so these are the third processes which are framing you know research concepts and this is where your research thesis or the paper which you write become policy papers for the government, do not think that nobody is reading these papers, there are a lot of guys who read and they communicate with you and they contact you and they ask for your help, is this clear, the genesis of ideas and how it goes up to the planning stage, ocean disposal, so there was a time people used to dispose of everything in the ocean, particularly the industry which are operating in the coastal areas, they thought that nobody is seeing, so you just dispose of everything in the ocean, sewage is a good example, now what happens during high tide, most of you are from the coastal belt, when high tide comes what happens, everything comes back to the ground, so ocean gives you back what you dumped over there few months or few weeks back, so this type of you know ping pong goes on, again you will collect it and you will dump it in the ocean, again one find it, ocean will spill out everything, this is particularly in context with the nuclear waste disposal and the thermal power plant which are operating adjacent to the water bodies, so what they used to do, they used to dispose of things in the ocean beds until the international agency started observing this and serving you notices, nations can get also known, so even the nations if they are not following, they will be served notice and even if after serving notice they do not follow then, okay, again if you do not follow sanction in the history, if you see in last 15 years what has happened and then suppose if you still do not follow the dictates war, so the whole story is connected from here to here, I hope you got all of all the idea, so if somebody says show me how are you managing your you know atomic activities, so these are the treaties, these are the proliferation rules which have been created and if some nation does not follow you have to face it, incineration, just now I talked about you know at very high temperature you try to convert from solid to the gaseous phase and this is the best way to deal with the hazardous waste but unfortunately question is do we have so much electricity as a nation, imagine what is the calorific value and city like Bombay where 4 months it rains, so most of the waste is in the wet form, organic matter, now if I am trying to incinerate it, I have to pretreat it, I have to precondition it, I have to heat it to remove the moisture from this, so these are the big challenges and these are not grams and few kilograms of the material which we are talking about, these are millions of tons, so bombasticity might be producing 7000 million tons of municipal solid waste per day, so imagine this is the magnitude of the problem which you are supposed to handle, different types of sewer disposal, septic tanks, whatever sediments are there, lagoons, surface impoundments all these are examples of you know how to dispose the waste and construction applications, construction demolition debris and resource recovery also comes in the picture, so this is the strategy which has to be created, this subject is a quite a demand supply type of a management skills sort of subject where you must realize that there are lot of industries which are thriving on the concepts of waste utilization, so this topic is now number one in all R and D activities, most of the time industries and government and people are supposed to be aware of what is happening in the country.