 lecture name is forms of waste. The subtopics which I intend to cover are waste generation their forms and when we talk about the forms there are two types of the forms that is hazardous waste and non-hazardous waste. Some examples of these waste and what is the difference between these types of the waste as the differences. In today's lecture I will try to emphasize that why characterization of waste becomes important, but I think you will appreciate the point that characterization is important. So, that you can utilize the waste properly, you can reuse it properly if you want you can recycle it properly and if you want to recover some precious materials then you can recover from the waste. So, this is where the characterization of the waste or the geomaterial becomes very important. So, next lecture onwards I will switch over to the characterization of material and when we say material it will be including both geomaterials as well as the waste. So, let us go ahead with the today's lecture. So, the first question is how waste is generated? So, basically generation of waste depends upon the source of generation is it not some type of waste they may degrade into harmless products. So, there is no challenge posed by them, but the biggest challenge is if waste do not get degraded over a period of time and that is where you need to handle them carefully and properly. So, the first category is that some of the waste may degrade into harmless products. However, majority of the waste may be non-degradable and they could be hazardous and most important is that there could be some cumulative effect related to detrimental effects or deterioration of the environment in the due course of time. So, this is where actually our role becomes important when we deal with the waste which are non-degradable, but hazardous and which may have long lasting effects on the environment. So, depending upon the type of process which you are adopting at the industry you may end up producing either solid form of the waste, liquid form of the waste or gases or the sludges. Now, sludges may include solid, liquid and gases all together. So, most of the time the challenge is to deal with the sludges which are coming out of all activities, industrial activities. Is it not? In day to day life also a single activity like let us say if you take bath in the morning or any household utility which you are going through the you produce lot of sludge. So, it may become very important to deal with the type of sludge which you are generating either at the domestic level or at the industrial level. So, as geotechnical engineers we have been quite comfortable and we have been quite you know equipped well with the handling solid waste and sludges. We have not talked much in details about the liquids and the gases, but a good example of the system where all these combinations may occur would be landfill. So, landfill becomes a very challenging problem particularly to geotechnical engineers. So, you dump the solid waste and this solid waste may deteriorate further or decompose or degrade and then the formation of liquid or the leachates may take place. Sometimes these leachates or the liquids may evaporate they may form gases or there could be some process by which you have to take care of the type of waste which you are generating in the landfills and so on. So, this is a basic summary of how waste is generated depending upon the source of generation. So, intensity of the waste or when we talk about the toxicity of the waste may be after few lectures we will be talking about characterization of the waste and that is where we will try to see what are the parameters or attributes which can be assigned to waste to classify them in some category. So, there are some attributes associated to the waste which we will be using later on, but to start with I think this information should be good enough to understand what a waste is. So, the waste generation is a process which is basically dependent on the source and if these are humblest products there is no problem, but non-degradable waste are going to pose lot of challenge and their cumulative effect would be very difficult to handle. So, what are the waste forms? The waste forms are we have talked about solid sludge which is nothing, but the semi solid liquid or gaseous or a combination of these and will depend upon the source of contamination and contaminants. So, this is where it is again very prudent to define what is meant by a contaminant. So, in one of the lectures I would try my best to give you some definitions about the contaminants and contamination process. There are few definitions which are associated with this whole discussion. So, this is the nature of the scientist they do not come up with you know uniform code of conduct. So, there are lot of definitions which are available. So, several definitions and the interpretations are available to define a waste. So, if you go by UNEP that is United Nations Environment Program, this is the definition which has been used to define the waste. So, waste other than radioactive waste which by reason of their chemical reactivity or toxic explosive corrosive or other characteristics. So, some of the attributes of a material which makes it a waste are chemical reactivity, toxicity, explosive nature, corrosive nature and other characteristics which may cause danger or likely to cause danger to health or the environment whether alone or coming in contact with other ways. So, this is where the interaction process becomes important alright. So, one waste may remain passive in its original form, but when it comes in contact with some other phase of the material it may become very hazardous. So, these type of ways are legally defined as orders in the state in which they are generated or in which they are disposed of or through which they are transported. So, very complicated definition, but of course, it covers most of the attributes of the material which will classify this as a waste alright. I will talk about these attributes later on as I said, but this just to introduce you a few definitions where most of the activities have been defined. So, what is the waste, how it becomes so important and then how would you classify this as a waste which is of you know threat to the mankind or animals. So, this process also very important. So, they are legally defined as orders in the state in which they are generated or in which they are disposed of or through which they are transported. In continuation with the definitions given by other people organizations. So, ways are the materials which are inherently dangerous to the human body or to animals. So, it is a simple definition. Anything which is dangerous to human body or animals is a waste material including, but not limited to materials that are toxic or poisonous. So, this is one of the attributes, they are basically irritants. So, you are passing through a fish market, what do you feel, what is the first reaction, yes exactly you close your nose or is it not. So, that means, the smell which is coming out is not very conducive, it is an irritation this is sort of it. You go and stand near the industry where the petroleum products are being refined or sulfuric acid is being produced or acids are being produced, how do you feel like on your skin irritation. So, attribute is that they are basically irritants. Now, irritation could be related to skin to observations feelings is it not by seeing something you may feel you know very low mood. So, that is also a written seeing a person for an example. So, you may say that how would you classify the person is of no use. So, waste then strong sensitizers, what is meant by sensitizers, sensations I do not know you must have felt that you are allergic to few things. So, sensitization is nothing, but you feel you know you get sensitized this is another attribute, they are flammable. So, the waste which normally we talk about they are flammable. So, you think of a situation where in a landfill you are dumping waste which include hydrocarbons and suppose you are not segregating them at the point of discharge. So, mixed together if this waste comes to the landfill what will happen during very high temperatures particularly in summers when most of the part of the country attains temperatures of the order of 46 to 51 degree centigrade. So, this is where actually flammable property of the material becomes very important. So, you have to be very extra cautious when you are dumping this type of waste in the landfill. So, flammable becomes another attribute explosive nature that is they generate power through decomposition heat or by other means. So, this is another attribute of the waste which makes them explosive in nature. So, what is the biggest challenge by putting these attributes together can you think of the challenge which a profession is facing. The chemical waste which is coming of the industry could be flammable and could be explosive and most of the landfills are within the limits of the city or slightly away from the limits of the city. So, by any chance if you are dumping the waste which contains everything together you know what is going to happen. So, you are creating a volcanoes within the city. So, this is becoming a very serious issue. So, they generate power basically this power is nothing, but the heat or sound through decomposition heat or by some other means. This is another trait of the waste material that is it is infectious. So, anything which may be infectious to you is also a waste material you like to throw it away and. So, that you can be safe against you know getting contracted by the diseases. So, this represents a potential source for transmission of diseases to human domestic animals or wildlife radioactive. So, there is another trait which is associated with the material which are classified as waste materials that is any component of radioactivity which is associated with the waste will also cause problems or hazard. So, that means any substance which contains sufficient amount of radioactivity will also be considered as a waste material pesticides. So, most of the agricultural activities these days are revolving around pesticides and fertilizers. So, excessive application of pesticides and manure or the fertilizers also becoming a very big challenge. So, some of the definitions which I like to continue is that the waste 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. So, they all fall in the category of waste. Hazardous waste are those waste which due to their nature and quantity are potentially hazardous to human health and or the environment and require special disposal techniques to eliminate or reduce the hazard. So, most of the people who are working in waste management they have to read these lines very carefully requiring a special disposal techniques. So, can you name any special disposal technique which is being adopted presently by our professionals it is banned by the way you are not supposed to dispose. So, simple thing which I am asking any special disposal technique landfill itself is a special disposal technique is it not. So, it could be engineered landfill or it could be ordinary landfill non-engineered landfills. So, idea is you dispose of something cover it and forget about it, but now presently society cannot afford to forget about it that is where actually the geotechnics starts. So, that is where actually the concern is how to deal with the waste how to tackle with it even if you dispose it in the soil mass or below you bury it how to forget about it. So, that it does not face or you do not face any challenge in the days to come. So, if you read this again you will notice that it requires special disposal techniques to eliminate or reduce the hazard. The best scenario would have been if you can eliminate the hazard, but truly speaking it is very difficult. So, what is that you will tend to do you reduce the intensity of the hazard. So, this is how you negotiate with the problem and try to come with the solution which is the most optimal solution. So, waste is the 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. So, you will notice that these words are very important actually improper management of the waste which is coming out of the industry. And what is that you are trying to do is or one should try to do is how to eliminate and reduce the hazardicity of the waste by some special techniques. So, this is where the entire waste management scenario or the technique strategies have been formed and there are lot of codes which you have to comply with. So, waste is any substance for which the owner or generator has no further use and which is discarded, but it should not be discarded in others courtyards. So, the common tendency is that in cities and other places they clean their houses and whatever comes out where it is disposed in front of the house on the road. So, houses are clean, but the cities are dirty alright. So, this is what requires education and enforcement. Let us talk about the types of waste. So, there are two types non-hazardous waste and hazardous waste. So, under non-hazardous category we say municipal waste and industrial non-hazardous waste. Hazardous waste industrial mostly. Can you give some example of municipal non-hazardous waste? Yes, it is not very hazardous that is right. Industrial non-hazardous waste, flash how would you characterize flash as a hazardous waste or non-hazardous waste? So, some are saying hazardous some are saying non-hazardous why it is hazardous? That is right correct why you are saying non-hazardous it is not stored anywhere. How much is being used of? Not more than 5 percent ok. We will talk about these sub issues slightly later. All industrial activities basically generate mostly hazardous waste. So, this question which I am asking you how would you say something is hazardous something is non-hazardous. So, there is a full gadget on this and that gadget is basically given by resource conservation and recovery act RCRA. So, those of you who may like to go for your own industries after few years you have to master this first RCRA. You have to understand the activity which you are going to get involved with and how to deal with that. Unless you understand this act you cannot get clearance from the environmental bodies, statutory bodies, environmental boards and so on conservation board and so on. So, basically what this act talks about any guess recovery comes much later. The first is resource conservation what is the resource which you want to conserve? Correction comes much later. The first thing is resource conservation. What are the resources which you want to conserve? Water, land, minerals, air everything clear. So, the first issue which it tackles is how to conserve the resources which you have and then how to recover something which has fallen in the matrix of waste. So, this is where actually I have used the word matrix. Matrix is very important. What is your understanding about the word matrix of the waste? Complexity of the waste. When you say soil matrix have you heard this term? I am not talking about the matrix which you used in mathematics. What how do you define matrix of soil? That is right. So, mixture of different constituents clear. So, when we say matrix of waste what is the meaning of this? There are different constituents in the waste which may exhibit different characteristics. Now, what is of most important to you? Which may come out of the waste and start contaminating the geo environment. So, the waste matrix is the matrix where all potential candidates which may leach out into the environment are sitting clear. Now, how would differentiate between what component of the matrix is going to be hazardous and non-hazardous? So, commonsense says the one which is more active is going to be hazardous, one which is passive is going to be non-hazardous. This is the one way to understand how non-hazardous and hazardous waste have been classified and grouped together. That means, the potential of the of the species is another word which normally geotechnologists will use when they deal with the waste management system. So, the species which come out of the waste matrix which are potential threat to the geo environment. So, this is a statement normally which is put up. So, species means it could be species of chemicals, species of radioactive material, it could be the biomaterial and so on and which has a tendency to leach out from the matrix of the waste and propagate into the system or migrate into the system.