 Having discussed lot of things regarding environmental geomechanics, now this is the time to start formally the concepts which are picking up in this domain and I will start discussion on soil-water environment interaction, this is a very contemporary topic which is being studied by lot of people all over the world, until now you have discussed mostly soil-water interaction in your undergraduate course. Remember whatever experiments you have done, you have created an interaction between soil and water starting from the hydrometer test where you allowed water to interact with the soil and then you try to analyze how this interaction occurs and you know how the settlement of the grains of the soils takes place. Beautiful example of soil-water interaction is the Atterbug limits, when soil comes in contact with water, whether it loses its shear strength or not is a very interesting philosophy. Similarly, the plastic limit, shrinkage limit indirectly these are the philosophies which deal with interaction of soils with water and then we have hypothesized liquid limit, plastic limit, shrinkage limit and so on to characterize the soil in a better manner. Similarly compaction characteristics, you know how soil and water when they react with each other, interact with each other and when external stresses, the impact loading comes on them and what happens when the material gets compacted is another interesting example of you know how compaction characteristics can be utilized to define soil-water interaction. So if you look at the compaction curve on the y-axis we plot gamma dry, though we have added water but mathematically we have filtered out the water to convert it into gamma D and we plot gamma D with respect to moisture content. This is also a good example of how soil-water interaction occurs, consolidation is another interesting example you know where soils are saturated and then you are interested in knowing how the pore-water pressure develops when the soil in the saturated state is externally loaded and of course the shear strand theory which all of you are aware of dry soils won't have much shear strength of course you can have shear strength provided they are OC materials, over consolidated materials. Now what I am going to do is I am going to superimpose on soil-water interaction the influence of environment and you must have realized the way I have defined environment is or the attributes of the environment are the nature mostly you know solar cycle, humidity, temperature, pressure, different type of environmental conditions which can be replicated. So now we want to study how soil-water environment interaction occurs and this is you know more comprehensive as compared to the soil-water interaction which you have studied until now. So with this in view to deal with the first of all the definition of soil-water interaction, environment interaction, the natural environment all of you are aware of this how human activities have modified this to man-made environment, we will try to understand what are the components of these two. Then of course what is the response of the soil to environment, different types of environments elevated temperatures, high pressures, low pressures, low temperatures you know different types of chemicals you know coming in contact with the soil in a saturated dry or a semi-saturated form and so on. Then of course we will be talking about the basic concepts, analysis of geomechanics problems. You know how geomechanics, conventional geomechanics deals with the issues what are the basic concepts and after having done all these things we will bulldoze the conventional geomechanics. So we will find out what are the flaws in conventional classical geomechanics which have to be rectified if we want to study soil-water environment interaction in a better manner. I hope by this time must have been clear to you that the conventional subject is not very you know complete, there are a lot of loopholes and I have been specifying and trying to highlight this concept until now so that you assimilate this thought. So let us start with this. Now this is the matrix which I would like to share with you that what is the genesis of soil-water environment interaction. So on one hand we have natural environment and on the second hand we have man-made environment and both of these are influencing the geomicro biosphere if you remember sometime back I had used this word geomicro biosphere which is the complete sphere you know the sustenance occurs in this, geo is something which comes out of the ground, micro biosphere is the one which constitutes most of the processes or most of the mechanisms or the soil mass itself. So if you remember the weathering process of the soils itself could be microbial alright and so this is a genesis of the material. Now what we are trying to understand is that how natural environment and man-made environment influence the geomicro biosphere and to quantify this concept because until now I think we have spoken a lot everything was abstract we have not used any sort of a hypothesis or a theory. People have proposed the particle energy field theory and the pronunciator of this theory was Professor H. Y. Fang who has considered the geometrical the particle which is sitting in an energy field alright. So for a quick example I am sure you must have realized you know how a charge sitting inside a parallel plate capacitor behaves you must have done in your 10 plus 2 physics for that matter even in X-ray cathode tube you know the X-ray beams are traveling and then you have electromagnetic force or electromagnetic field and you have electric field and magnetic field. So this is the electromagnetic field and then you want to find out what is the path traversed by the electron alright these are beautiful examples. So similarly this concept we will now extend to the soils or the geomaterials this could be rocks this could be soils this could be ground water and we want to see what is influence of different types of energy fields and energy fields are going to depict environment alright. And the whole idea is that we would like to use this concept to solve the problems of the environmental geotechnical engineering or geo environmental issues which are bothering the society. Now if you want to deal with this theory basically we have to understand the response of the geomaterials in two forms one is the short term or another one is a long term. So most of the practices of conventional geomechanics were shorter you know the consolidation also was completed within few days but suppose if I want to study in a prolonged manner what is happening after let us say one year of testing of the soil sample in a falling head per meter alright and particularly when the permeant permeant means the fluid which is passing through the soils is not pure water it might be having contaminants and if you remember the attributes of the contaminants which we have defined are elevated temperature very high concentration of chemicals very high radioactivity microbial activity you know it could be charges also electrical charges. So all these things constitute to the a contaminant so imagine a fluid which is having all these attributes is now passing through the porous media and I want to understand the short term and long term behavior of the permeation. So I am sure now with this concept and whatever background I have given to you you can realize this is going to be a very intricate subject to study. So the challenge is how to model the behavior in the short term and long term to by using the particle energy field theory to get the solutions to the problems which we are talking about. Now it so happens that when you are dealing with this particle energy field theory you will realize that the background from different subjects is required you must have got a feel of this the way I have been discussing it is a multidisciplinary subject alright it is not confined to a particular stream as such. So to my knowledge when you deal with particle energy field theory the knowledge of bacteriology we were talking about how bacteria migrate from one place to another place in the porous media and just now I gave you an idea that the fluid which is passing through the porous media in a falling head testing device might be containing pathogens might be containing bacteria might be containing microbes whatever. So I want to see how the concentration the microbes is changing in the porous system with respect to time and with respect to the distance alright. So bacteriology biology chemical engineering climatology, geohydrology geophysics geochemistry hydrogeology mechanics of course you cannot be forgotten microgeology physical chemistry and soil sensors and soil engineering and toxicology. So these are the subjects which have to be you know dealt with when you are talking about the application of particle energy field theory. So this is what explains you know or with this what I am trying to do is I am just trying to set the tone for the discussion on soil water environment interaction. If you try to understand what is meant by the natural environment I think we can define it easily whatever nature had given us a beautiful you know stream of water. If you go about 10, 20, 40 kilometers away from Bombay city you will find very serene environment particularly when it rains it looks so beautiful. And so this type of serenity is getting lost alright because of the whatever genesis we have talked about of the environmental geomechanics. Now this is what we say is atmosphere so atoms you know atmosphere with the vapors or the dust atmosphere consists of the vapors and the dust and we talk about the biosphere. So biosphere is the one in which the flora and fauna survives and this survives because of the oxygen nitrogen and carbon cycle and these cycles are basically the cycle of the nature. You must have studied in your 10 plus 2 I am just reminding you. So then we talk about the hydrosphere hydro is water and you know the water is present in different forms and these forms are it could be in the oceans, it could be in the lakes, it could be in the aquifers, it could be in the form of the ice or it could be in the form of the clouds. So if you remember we have talked about all these things frozen state geomechanics deals with the water in different states you know in the geomaterials. We talk about the lithosphere, lithos is the stone alright. So we talk about stones, rocks, soils and hence the natural environment consists of atmosphere, biosphere, hydrosphere, lithosphere and geomicrobiosphere. So what is geomicrobiosphere? This is basically ecosphere which consists of the entire thing. Now what we would like to do is this is something which is of interest to the climatologist those who talk about the climate sciences. Now we are more interested in starting from this as a benchmark you know what has happened because of industrialization, because of overpopulation, because of land you know scarcity, because of the resource scarcity and so on. We would like to understand first what are the natural components, what are the components of the natural environment and then we will try to see how these natural components have got shifted or changed because of the present day civilization. So geomicrobiosphere or the ecosphere talks about the trees, vegetation, roots, bacterial activities in the soils and water and overall response. So sometime back I was citing here that the contemporary geomechanics deals with the soil, root zone, microbes, environment interaction. So if you have studied this editorial which I wrote, you must have realized that this is where the more emphasis is right now and people are trying to understand how vegetation can be utilized for stabilization of the slopes alright, these are bio inspired geotechnical engineering practices. So if roots can you know stabilize the soil and if the soil cover stabilizes the slope can I use this concept to do reverse engineering or bioengineering to make the system stable. So coming to the manmade environment you know what human activities have done, sorry before that I will discuss the cycle of the nature which I am sure you must be aware of. Oxygen cycle is something which is the genesis of the oxides you know which are present in the soils or for that matter in any matter. So most of the time as a geotechnologist we are interested in oxides of silica and alumina and iron and you know magnesium and sodium and potassium and so on. And this is what is analyzed by using XRD analysis, I will talk about this X-ray deflection analysis. So most of the silicates, aluminates, metallic oxides, carbonates, sulphates, nitrates and phosphates which we are using these days in the name of fertilizers or discharges which are coming out of the industries are a good example of oxygen cycle alright. So these materials or the metals got oxygenated, oxidized and hence these oxides are formed. The second thing is nitrogen cycle. So nitrogen is also an element which is useful for the survival of flora and fauna. So this is how we talk about the transfer of nitrogen between the atmosphere, biosphere, and atmosphere in different forms alright. So we use the examples of nitrogen fixation alright. You must have talked about eutrophication of the lakes and the water bodies. Then comes the carbon cycle. So oxidation of the carbon which is present in the material. So carbon dioxide formation and this requires photosynthesis. So this is the natural cycle and I hope you can realize that as a geotechnologist, environmental geotechnologist we try to utilize these cycles in a better manner alright. Just as a refresher I thought I will just discuss these things with you. Now if you take the manmade environment this is quite alarming. So first of all this is the picture you know a dire contrast against what I showed to you sometime back, later, later everywhere and this is how most of the cities can be defined right now. You know in the heart of the city we will have landfills and landfills are the place where the people survive and so on. So what are the components of the manmade environment? You normally talk about the solid phase and the liquid phase alright, gaseous phase as I said we normally do not consider in our subject and this is something which we leave for the environmental scientist or maybe the second logic could be whatever goes in the gaseous phase will come back you know once the precipitation occurs, not a bad idea. So this is the list of you know manmade environment. We have different types of agricultural ways, agriculture was supposed to be a very neat and clean activity but no more because of the dumping of lot of you know manure or the fertilizers. We are over fertilizing the land, we discussed this sometime back you know and what are the social consequences alright, this is shown very well depicted in some of the movies that now nobody is interested in agricultural practices and hence what is happening this so there is a disorder in the society. So any type of agricultural remains create manmade environment, human and animal based I think I gave you ample examples of biosolids the sludges which are coming out of different treatment plants, water treatment plant, sludge treatment plant and I think I cited these examples that the big question is if you do not clean up your lagoons or the septic tanks or the water holding ponds or sewage holding ponds you know you cannot sustain the processes, sustain the society. So sewage has to be treated, water has to be treated and these are the places where the sediments which get deposited in the lagoons or in the ponds are having pathogenic activity, microbial activity, bacterial activity alright. So the question is if I have to clean up these lagoons or the ponds how and where I should dispose the sediments. So this becomes a manmade system I think I cited one example and one of my PhD scholars also worked on this topic Dr. Sushmita Sharma she is presently faculty member at NIT Meghalaya. So we coined this term as SEGS socio economically generated sediments alright there is something interesting which flashed our in our mind let us talk about SEGS SEGS that is socio economically generated sediments. So every country because of its socio economical condition produces the sediments clear and now the big question is where to dispose them. Similarly another example would be biosolids. So biosolids see again the question is they are pathogenic in it. So another issue is you know the biosolids where you are going to dispose them how you are going to handle. So I think I asked you to search on the Google also what is being done with the biosolids particularly in countries like Australia and India we do not have any clues and again these are the sediments which are to be handled by geo technical engineers environmental geo technologies. Like if you go to an STB like today sir they have like all the facilities to treat the sludge and the this biosolids they make like anaerobic like anaerobic processes they do to dewater the sludge and then they make cakes out of it and sell it to people that I have. Everything is confined to the books the fact is this and the treatment also aerobic anaerobic treatment also requires time. Do you think that in our society we have so much time to wait for anything to happen. Imagine the tons and the millions of tons of the discharge which is being done every hour alright. So the ground realities are different you should if you are very serious you should be looking on the net what is happening with these materials and why they are becoming a big issue. So animal waste is also becoming a very big problem particularly related to the agricultural sectors particularly the animal caracas you know after they die what to do with the dead bodies in flash floods particularly there was a situation like this which happened in Bombay a few years back I hope you are aware of this and then the biggest issue was that the lot of animals died and what to do with their caracas. Then of course industrial waste which will be handling separately because this is beyond imagination and the volumes are so big that cannot be discussed in just as a passing remarks. So we will be talking about this separately. Mine waste you must have heard about the acid mine drainage on which jasmine is working. So the acids which comes out of the coal mines and the type of hazard which it creates and the reason is known that most of the time the coal has Fe2S sorry FeS2 iron sulphide and this gets converted to H2SO4 or this could be pyrite also. So these two things might get converted into acids and these acids drain out and they form draining acid draining mines a big problem you cannot leave the mines unattended. Is it possible to collect it and commercially use that acid? Well you can but the biggest question is most of these mines are in remote areas. So that is what the first question is that people like you should be going there or not. You know where the most of the mining is being done in Kokraja district of Asaf. So the volumes of the acids which are getting discharged how to pack them and concentration is a big question. And then purity then the question is somebody has to run an industry to maybe you know create concentrated acids and then use them but again the purity is going to be a big question alright. Your idea is good. So maybe you can think of some startup and you try to convert acid mine drains into acids it can be of some commercial application. What we are trying to do is we are trying to marry the acids which come out of the mines and you want to neutralize some industrial waste by using this concept. This is possible that is the whole concept on which Ghanaraj is working and Jasmine is working. Then comes the nuclear waste of different types I think we have discussed a lot about this and I will not touch upon this now much more because except for citing some examples of what has been done by us in the past and to show how you know guidelines can be developed by scientists to safeguard the geo environment against radio nucleates impregnation. And of course the construction effects you know blasting when you do a lot of destruction occurs tremors micro tremors get produced you do dewatering for different projects and the construction and demolition debris are a very big issue what to do with this city like Bombay. How many multi story buildings you will be having and what is the life of the concrete in city like Bombay you know because of heavy chloride impregnation. So this is the corrosivity of the concrete which I am referring to and every 15th year the building requires refurbishing so the volumes of C and D waste which you are creating or what formative earthquake comes and the buildings get uprooted alright. So how would you handle the C and D waste is a very big question. Now these are the issues which people never thought about earlier but now I am sure that you know society is forcing her to think like this.