[0:21]Good day everyone and welcome to these lectures on Physico-chemical processes for waste water treatment. So today we are going to start our lectures on the treatment of water and waste water by various physico-chemical processes. So we'll start with that why we need these type of processes for water and waste water treatment. What are the what are their importance and what will be covering in this course. So today we are going to discuss all these aspects. So let us start and understand what are what are the various environmental crisis that is there in the present decade or thereafter. And why this has a reason and what we should do so as to tackle these aspects. So environmental crisis has started after the industrialization has fastened all throughout the country as well as globally. So large scale contamination of water and air has happened because of this industrialization. So the society is requiring new and new type of facilities along with that they require lot of energy as well as other types of chemicals and products which can be converted or used in our day to daily life. And because of this industrialization and also because of the growth of infrastructure, etc. So large scale contamination of water and air both has happened and for industrialization, we require lot of land, lot of water as well as other utilities. In addition, we require lot of wood and metals and other. So for taking out like wood, we have to do deforestation. Similarly, if we require metals, so that means the mines have to be dig and from there alloys, etc., are different types of materials have to be taken out. And for which the deforestation has to be done so that we can take out the resources from mother earth. And because of this deforestation, the characteristic of land as well as the air has changed. So also because of industrialization and rapid growth in the population, the increase in urban slums has increased because of the movement of the people from the villages and sub urban areas to urban areas. So these urban slums have increased day by day. And all these issues are highly challenging for our society. Generation of huge solid waste consisting of hazardous materials as well as simple municipal solid waste has also increased because of usage of lot of material in our day to daily life. Now industries use lot of metals, non-metallic material, organic materials and other things and convert them into various products. During this conversion, lot of waste is discarded as well because of their various characteristics, these waste may be hazardous in nature and they cannot be reused or recycled. So they have to be either kept aside and just used for land filling, secure land filling, etc. So larger lot of solid waste is getting generated, which has these hazardous characteristics. Similarly, from residences, because of use of lot of package materials, the amount of municipal solid waste which is getting generated from residential colonies, etc., is increasing very quickly. And the we have to see that how we can manage these waste. Similarly, because of the uses of lot of energy sources and because of the combustion that is happening not only inside the residences but also in various furnaces, engines, etc., which are running all the society, the CO2 emission is taking place and the global warming is happening.
[5:07]Similarly, the because of the usage of lot of CFCs and other types of material for refrigerant, the ozone layer depletion is well known. But in this present course will be discussing more regarding the water scarcity or in particular how to tackle the water issues in particular the water pollution. So how to take care of the needs of the society with respect to drinking water, irrigation water, industrial water and after their usage in various residential and colonies as well as in the industries. How to take care that these contaminated water is not discharged back into the aquatic bodies. So that these aquatic bodies still remain as such. So all these aspects will be covering in the present course. Water scarcity is highly alarming. All those places where 20 30 years back water scarcity was never thought of, now there is the water drinking water is also not available. If it is available, it is contaminated with lot of materials, which because of which the water cannot be used for drinking. Similarly, because of over exploitation of water for irrigation and for various other purposes, the ground water depletion has occurred in most of the places in the country. And because of which the availability of ground water has also gone down and we have to see that how we can tackle these problems which are increasing day by day. Going further because of industrialization, the industrial pollution has increased and this industrial pollution has caused lot of issues. So what are the major concerns that are associated with industrial pollution? Water and air pollution from chemical process industries need highly immediate attention. Now, the chemical and process industries, they make lot of chemicals and products which the society needs.
[7:44]Now all the products that we see generally day to day life starting from may be clothes, all the all the material that we use all the plastics, these these everything is made from petrochemicals or some other chemicals. So the usage of chemicals, petroleum products, petrochemical products has increased day to day life and because of that these chemical and process industries are increasing. And the water and air pollution from these industries is different as compared to that from municipal waste water. So the treatment strategies or the control strategies with respect to water and air also need to be different as compared to from common sources where the pollution is occurring. So these the water and air pollution from these industries require immediate attention. Similarly, industrial waste water, which is generated from these industries as well as various other industries, they vary widely in their composition and their their characteristics may be entirely different.
[9:04]So some waste water may be highly acidic, some waste water may be highly basic. Similarly, the pollution load in some of the industries may be entirely different as compared to other industry. Similarly, the some key type of elements may be present in one industrial waste water, which may not be present in another waste water. So depending upon the industry where this manufacturing is occurring and from where this waste water is getting discharged. So their composition is likely to be highly heterogeneous. So under that condition, the treatment methods also need to be well understood so that we can apply different treatment methods and their strategy of application has to be different and that will vary depending upon the composition or the type of waste water being discharged from that particular industry. Many treatment practices that we are following in our country, many times they require what they do is that mix the liquid sewage waste, which is like municipal waste water, along with the industrial waste and then they treat the water by conventional method. This may not be accurate and we have to see that the treatment of industrial waste water has to be done to up to a certain level before mixing the municipal sewage. Because their characteristics are entirely different and the conventional treatment methods which are used for treatment of municipal waste water may not be correct for treatment of industrial waste water because they may contain different type of pollutants which are entirely not present in the municipal waste water. So we have to understand the characteristics of the waste water as well as understand the various treatment methods and their basic know-how that how they work, what are their possible efficiencies and which type of water quality parameter they are able to remove as compared to other methods. So if we have that understanding, we can develop a treatment train for some particular waste water, which may not be applicable for another industrial waste water or municipal waste water. Treatment methods such as lagoons (aerobic and anaerobic), oxidation ditches and aerated lagoons have also been tried but they may not be good enough for treatment of industrial waste water in particular. Majority of traditional treatment methods if they have been applied for industrial waste water, they have failed and because these conventional treatment methods, they are not able to remove various other pollutants which are present in these industrial waste water and they are not able to remove. So these pollutants remain in the water after treatment also. So omission of these key parameters. We have to see that these key parameters still have to be taken care of while the treatment of industrial waste is being done along with the biological treatment as well as other treatment methods. So we have to see that how we can take care of these key parameters which are may not be present in the municipal waste water but they are present in the industrial waste water. So for treatment of such waste waters which have some different parameters, we require physico-chemical methods for treatment of such waste waters and these methods are necessary to remove or recover the chemical ingredients which may be present in the liquid effluents for many industries like electroplating, chlor-alkali, pesticides, fertilizers, dyes and pigments, metallurgical, paper and pulp, etc. So all these industries, which are there, their composition may vary entirely. These waste water may contain some key parameters which will be entirely different than other industries and certainly these parameters are different as compared to municipal waste water. In addition to treatment of waste water, the reuse of water in the processes, which are being practiced in these industries, is very, very important. So we should try to recover most of the water and reuse in the processes industrial processes, so that the actual water demand decreases and the actual waste water which is has to be discharged is also lower in quantity. Now the pollution due to chemical process industries. The primary causes of industrial pollution in the chemical process industries is because of the use of outdated and inefficient technologies. So many these industries are very small and they practice inefficient technologies, they are using such technologies which are outdated and they are not able to remove these key parametric water quality parameters which may be there in that industry.
[14:59]So we have to see that these outdated and inefficient technologies which are there for product manufacturing, pollution abatement and various other operations which are being practiced in these industries. They have to be omitted and new technologies have to be used in these industries. Also, in our country, the development of unplanned industrial clusters without forcing the effect on environment has been done. Now, in last few decades, the government is taking lot of care with respect to these aspects that we have industrial clusters where maximum care of environment is taken, but still there are many places where these unplanned industrial clusters are there and we have to see that how the environment is still taken care of in these old clusters or any new industrial cluster if it is getting developed. The existence of small number of large number of small scale industries, which actually resist using money on these pollution control norms is a challenge and we have to see that how they can be we can develop technologies which can be used by these small scale industries.
[16:57]Now, the poor implementation of the pollution control laws by the industry is one of the basic problem which is there with respect to pollution which is occurring from these chemical process industries. And certainly this implementation aspects have to be improved for checking the pollution which is happening because of these industries. There are many major polluting industrial sectors in the country and these are listed here and many of the other new type of industries are evolving in our country. So there may be industrial sectors beyond these sectors where which are considered to be highly polluting. So these include So and this this polluting nature is here referred to with respect to both air, water, soil, but some of the industries may be having more air pollution, some of the industries may be having more water pollution.
[18:01]So we have to see but the common industries are listed here. So these include cement, thermal power plants, iron and steel industries, fertilizers, where different types of water may be getting discharged having different characteristics. Then zinc smelters, copper smelters, aluminum smelters, then oil refineries, distilleries, pulp and paper, dye, all these industries are major chemical and process industries, which generate lot of pollution. And all these chemical and process industries, they also not only generate water waste water in high quantities, their characteristics are entirely different and pollution load is also high as compared to municipal solid, municipal waste water, etc. So we require basic understanding of various physico-chemical processes for using them properly in these industrial sectors, so that the water waste water after treatment is good enough to be discharged as per the Government of India norms.
[19:17]Now environmental engineering as a subject is evolving very quickly and in the last few decades, it has become very, very important. Traditionally environmental engineering was considered to be a part of civil engineering, but many other disciplines of engineering, in particular chemical engineering, is now playing a major role. Along with that, many science disciplines are coming into picture. Now environmental engineering as per definition as per the book peavy at all, it is that branch of engineering that is concerned with protecting the environment from the potentially deleterious effects of human activity, protecting human populations from the effects of adverse environmental actors and improving environmental quality for human health and well being.
[20:16]In general, the environmental engineering, environmental engineers need to protect the environment, protect the human population from the effects of the environmental changes and also improve the environmental quality so that the human health or the life any other life health and well being is maintained.
[20:40]So this particular branch is more closely related to chemical and civil engineering as compared to other, but it is associated with other disciplines as well, which includes chemistry, physics and biology and also it has lot of elements of hydrology, meteorology, atmospheric science, environmental chemistry, microbiology and ecology. So these things are there. So it is a more of a interdisciplinary branch with major content from chemical and civil engineering. So this is there. And this particular aspect is evolving a lot and its importance in the society is increasing day by day. Now some of the important definitions which are there with respect to environment or environment pollutants are given here. So environment in general is water, air and land and the inter relationship which exists among and between water, air and land and human beings, other living creatures, plants, micro-organism and property. So this is how the environment is defined. So similarly environmental pollutant means any solid, liquid or gaseous substances which is present in such concentration and may be or tend to be injurious to environment. So any any substance if it is present in quantity beyond a certain concentration, after which it starts affecting the environment, it is considered as environmental pollutant. Many of these pollutants will not be considered as pollutant if they are present in below certain concentration limit. So concentration is the key parameter with respect to defining whether anything is environmental pollutant or not. And also sometimes or many a times how much time that pollutant is present at that concentration, that also affects the its definition that whether it is a pollutant or not. So concentration and time, these are two important parameters based upon which the pollution terms or environmental pollutants are defined. Water pollutants means any solid, liquid or gaseous substance including noise present in the atmosphere in such concentration as may be or tend to be injurious to human being or other living creatures or plants or property or environment.
[23:38]So any of these solid liquid gaseous substances if they are present in the atmosphere beyond a certain concentration and if they are affecting human beings or other living creatures plants property or environment, they are considered as water pollutant. Now water pollution means the presence of impurities in such quantities. So the quantity is very important and of such nature as so as to impair the use of water. So if any water is there and it has certain impurity present in such quantity that we cannot use it, the water whatever designated purpose may be drinking, may be agriculture, may be bathing, may be industrial use, may be fishing, may be recreational, then that will be called as water pollution. So remember, suppose we have to use a water for drinking and it contains some pollutant. So certainly that pollutant should be present in minimal water quantity because that can affect us if we drink that water.
[24:50]Now suppose the same water has to be used for agriculture. Now we can go on beyond that concentration and may be used some more concentration can be avoided in agriculture. Similarly, for bathing also, we can avoid little higher concentration. So concentration is very important parameter with respect to the designated purpose for which water is to be used. Now, similarly, some of the impurities that may be there for some designated use, they will not be considered for other designated use. Suppose we have to use a water for a steam formation in industry. So under that condition, we have to avoid all the TDS, etc., because that will form scale if it is present in the water and if it is used for steam generation. Now the same water, it is possible that we can use it for drinking or bathing. So so one key parameter, it is possible that it has to be totally avoided for one designated use, but it may be used for other purpose.
[26:10]So any of these both concentration, time and then the designated purpose for which the water has to be used, that becomes very, very important. Why we require treatment of such water or waste water. Now water for drinking or industrial purposes obtained from various aquatic bodies (rivers, lakes, groundwater).
[26:41]Now if the if the water is not good enough for drinking, then we have to treat that water. So water treatment is required for this water before its use in residences and industry. Now, once they are used, after usage, the pollution load will increase in the water discharged from residences and industries. So depending upon the final discharge point or reuse of this water, the waste water which is discharged that has to be treated further before discharging the water into any end point or discharge point.
[27:39]So that is waste water treatment. So this waste water is the water which is already used and water treatment means the water which are getting from natural sources like rivers, lakes and ground water.
[28:10]That has to be treated if it is containing any pollutant or any undesirable thing before its uses. So these are these that's why there are two terms, water treatment and there is another term which is called as waste water treatment. So remember this. Now, what will be studying in this course? So this is given here. So this particular course will be discussing physico-chemical processes for waste water treatment.
[29:49]So we'll be starting with the introduction of water pollution and control and within this section, we'll be studying in detail the water quality parameters. So will be devoting lot of time with respect to water quality parameters. So what are different physico-chemical water quality parameters and how they are analyzed? What are the basic understanding of these water quality parameters? So what are their effects on the environment on human health or other uses? So depending will be covering all these aspects in the introduction of water pollution and control. Within this, we'll be discussing regarding the pollution control norms, etc., are also and also what are the different standards which have been prescribed by Government of India. So we'll be covering everything of this in the introduction. So there will be, this will be the first section. After that, there will be a pre-treatment and physical treatment section. So waste water treatment strategy actually involves three, four stages. So that these include pre-treatment, physical treatment, biological treatment, then tertiary treatment. So we'll be avoiding, will not be discussing biological treatment, but we'll be discussing pre-treatment, physical treatment, tertiary treatment, etcetera, in this particular course. So we'll be discussing flow equalization, aeration, coagulation and flocculation. After that will be discussing settling and sedimentation, the settling chamber design certainly. Then filtration and filtration system design. Thereafter will be going further and studying the water and waste water treatment by adsorption and ion exchange. Further, will be discussing the waste water treatment via membrane based technologies. So that will include microfiltration, ultrafiltration, nanofiltration and reverse osmosis. So these are being practiced a lot nowadays. So we'll understand the all the basics and a little bit more detail of these technologies. Further on will be discussing the advanced oxidation processes. Nowadays a large number of chemicals and newer types of chemicals emerging pollutants are there. And these are getting produced from pharmaceuticals, insecticides, various other types of chemicals including surfactants, etc.
[32:44]So these chemicals are coming slowly and slowly into the water and many traditional chemicals which are produced by industries, they also cannot be treated by conventional means. So these these pollutants need to be mineralized. So for this, we are we have to use advanced oxidation processes. So we'll be discussing regarding the advanced oxidation processes in detail, including Fenton processes, catalytic treatment, photocatalysis, Sono and electro-chemical treatment methods and their hybrid combinations as well. And these processes can also be used as disinfection process because new types of bacteria, virus and pathogens are coming into the water. So many of these advanced oxidation processes, they can be used for disinfection. So we'll be discussing the disinfection also within the advanced oxidation processes. Going further, in the last, will be discussing waste water treatment in some of the chemical and allied industries as well as in the common effluent treatment plant. There is a a term which is called as CETP. So we'll be discussing the how the treatment of water waste water can be done in these industries. Some examples will be taking so that we can understand that what is the how the treatment strategy depends upon the waste water characteristics, which are discharged from different industries. So in the last, we'll be doing that. Similarly, in industrial clusters, the utilization or usage of CETP is increasing. So we'll be discussing common effluent treatment plant in the last. So this will be the course content of this particular course. Why attend this course? It will, it will help you understand the various environmental challenges and its protection, in particular the water issues. Also, it will provide the basic understanding with respect to what should be the expectation of the industry with respect to pollution control within their premises and what are the new and tougher laws and acts that are being enforced in India and globally. So these are going to be enforced anyhow. So we should have the basic understanding that how different types of physico-chemical operations or unit operations can be used for waste water treatment. So this knowledge will be provided in this course. So you'll be getting lot of technical knowledge for sustainable water management and also will be getting to know that how we can use these strategies for getting drinking water as such. So all these aspects will be covering within this course. So this particular course will be providing the basic understanding of water quality parameters. Sources of generation of waste water in various industries, what are the various physico-chemical process technologies and how they can be applied in the industries, how to treat water with the available technologies depending upon the composition of the water. Some recycle reuse aspects of the water will be covered and also will be understanding the how the effluent treatment plants can be better designed via using these physico-chemical processes. So all these aspects will be covering in this course. You are welcome to understand all these physico-chemical aspects and all these will be covered within this course. So these are the differences that I have used in the present slide. Thank you very much.
