Hello everybody, how are you? I hope all of you will be fine. So let's start today's topic.
Today's topic is sanitary engineering. Sanitary engineering is very important topic for sanitary or civil engineers as well as environmental engineers. There are various subtopics.
are in this sanitary engineering topic like removal and disposal of human waste, sea waste treatment and disposal, portable water treatment and solid waste treatment. So all these are the subtopics of sanitary engineering. So today we will discuss the first part of sanitary engineering that is removal and excretion of removal and disposal of human waste. Removal of disposal removal and disposal of human waste is a very important topic as food is important for us same way safe disposal of human waste or defecation of human waste is also important otherwise it will contaminate the environment our air soil and water and ultimately it adversely affect to our health so today we will discuss removal and disposal of so first thing that become that come in our mind is what is sanitary engineering uh basically sanitary engineering public health engineering wastewater engineering are synonyms or a somewhat similar names so sanitary engineering is a application of engineering methods this is the application of engineering method for what to improve sanitation of human community So, sanitary engineering is just the application of engineering methods to improve sanitation of human communities primarily by providing the removal and disposal of human waste. Okay, so what is sanitary engineering?
It is nothing. It is just the application of engineering method just to improve the sanitation of human communities. And how it will improve the sanitation of human communities? providing the removal and disposal of human waste. With this, there is an additional role of sanitary engineers is to supply of safe potable water.
So, it is the branch of public health engineering dealing with collection, convince and disposal of wastage. So, wastage we discussed here is garbace, sludge and seaweed. So, there are three aspects of sanitary engineering.
First one is the collection of human waste. Second one is the conveyance and third one is disposal. Collection of solid or liquid both type of wastes are collected in especially in stored lavatory blocks.
Conveyance this include provision of drainage line for the conveyance of solids and liquid wastes which are collected. And third step is or third aspect of sanitary engineering is disposal. Very important step.
the convince or refuse waste is treated as dispose of so these three are the aspect of sanitary in compared to another in the other engineering brands sanitary engineering is a interdisciplinary field why it is interdisciplinary field because it involved different persons from different field like it involved uh plumbing elements it involved fire protection hydrologics, life safety, constructive modeling, microbiology, pathology, information technology, project design and the many decisions within environmental science and environmental technology. So as other engineering branches concern in closed system, this sanitary engineering is a interdisciplinary field. It also includes urban planning, uh Although sanitary engineering may be most associated with the design of sewer, sewage treatment and wastewater treatment facility, recycling centers, public landfills and other things which are constructed, these terms applied equally to the plan of action to reverse the effect of water pollution or soil contamination in specific areas. So, the sanitary engineering involved or the main role of sanitary engineering in the designing of the sewage designing of the sewers or seawaste treatment and wastewater treatment facilities and other things. With this, it's also involved in or it also applicable in plan of accident to reverse the effect of water pollution or soil contamination.
specific areas. There are various terms related to sanitary engineering. First thing is simply what is sanitary engineering? It means application of scientific or mathematical principles. So, we can say sanitary engineering means application of scientific methods or engineering application of engineering method with to the field of sanitation especially in regard to its effect on public health.
Sanitation is is the hygiene means of preventing human contact from hazards of waste to promote health. So what is sewage? Sewage is one type of wastewater of community and is a major actual or potential source of pollution. So sewage is a wastewater that coming out from the communities and it has potentiality to pollute the water or it act.
actually act as a water pollutant and it conveyed by sewer. There are basically three types of sewage. First type of sewage is the domestic sewage or we can say sanitary sewage. Domestic as the name suggests, this type of sewage are coming out from the residential buildings, business centers and institutions.
This also contain human body waste, pieces and urines and also sludge water. Second type of sea waste is industrial sea waste. Industrial sea waste is the liquid waste that obtained mainly from industrial areas like dyeing industries, paper mating industries and many other type of industries. Third is the storm water, storm sea waste.
This is the part of surface runoff which is flowing in sea water during the rainfall period or following period of rainfall. Another term is sewage effluent. What is sewage effluent? This is an outflowing of water from sewage treatment facility or the waste water discharged from industrial facilities. So, when the water coming out from sewage treatment facility or waste water from industrial facility, this is called effluence like this sluzz.
what is sluzz sluzz is the waste water resulting from personal washing bathing laundering food preparation and cleaning of tensils it does not include discharge from hospitals ots and slaughterhouses there are some spelling mistakes in this slide slaughterhouses which has high content of organic matter so sluzz is not very foul and can be disposed of in open drains without treatment solids. What is garbage? Garbage may refer to the waste or also known as trash or junk, unwanted or undesired material.
So, garbage is basically the trash or junk material that is unwanted or undesirable. The garbage may be organic, may be inorganic solids, semi-solid, combustible, non-combustible. or non-prescribable substance. It also includes sweeping from houses, streets, market, public places, etc.
So, it is collected separately from sewage and sludge and disposed of separately. Next term is wastewater. Wastewater is the water that has been adversely affected in quality by anthropogenic influence.
Greywater is another term. It means slush in non-industrial wastewater generated from domestic purpose such as dishwashing, laundry and bathing. So the wastewater that coming out from the domestic sources and resultant from the domestic processes like dishwashing, laundering and bathing is called greywater.
Another term is infiltration or hydrology. Infiltration or hydrology means downward movement of water through soil. Water in turning the seaways from the grounds where inflow is in turning of water into the sewers from the surface sources through cracks in main holes etc. Whereas exfiltration is opposite to the infiltration.
In filtration means downward movement of water through soil whereas exfiltration is upward movement of water through soil. Seawaste treatment or domestic waster treatment means This means process of removing contaminants from wastewater both runoff and domestic. It includes physical, chemical and biological process. So all the physical, chemical and biological process that helpful in the removal of contaminants from wastewater come under the sea waste treatment or domestic water treatment. There is anaerobic digestion.
digestion of organic matter by anaerobic microbial actions or anaerobic microbes involving digestion of organic material and resulting in production of methane gas is called anaerobic digestion and facultative aerobes or anaerobes microbes having the ability to leave either with or without oxygen means microbes can easily leave in presence of oxygen but if there is absence of oxygen then also this type of microbes can survive. And biodegradable means capable of decomposition by so the role of sanitary engineering is very important and the sanitary engineering is all become essential with the rapid increase of cities and other rural population centers. Sanitary engineering fields involve or sanitary engineering fields have four responsibility it help in water supply it help in waste water management sanitary engineers help in strong water management as well as in solid management so in water supply it its function included water collection to water treatment to water distribution means from water collection to water distribution the second is the wastewater treatments again it involved in collection system treatment and reuse or disposal of waste is collection system to disposal of water or distribution of water so the role of sanitary engineers is very important and become essence of the sewage system and industrial sewage is coming through separate sewage system. Strong sewage it is the one which carries strong sewage including surface runoff and street wastes.
Continued or combined sewage include or carry domestic industrial and strong series combined so separate series has have many advantages as well as disadvantages it has the first advantage the load on a treatment plant is less as only fever is carried to the plant so separate server if there is the separate severs for series for sanitary sewer and strong sewer so the load on treatment plant is less as compared to the combined sewers the size of sewers are small thus economically this has a small sewer size again and this has a small sewers two small sewers size separated small sewers size sewers are present when pumping is required the system process to be economical because in sometime this sewers is required pumping and sometime you this service is required something so this is a economical process when pumping is required so this is economical and natural water is not unnecessarily polluted by the seaways but there are disadvantages of this method also cleaning of sewer is difficult due to their small size okay because they here there are two small sizes sewer so the cleaning is difficult due to its small size and self cleaning velocity is not easily achieved The maintenance cost are high because here we require two cost of sewer making. So the maintenance cost is high. The storm sewer come in operation in rainy season only because the water that come in storm sewer is only come out from the rain floor. So this sewer work only in rainy season.
They may be chocked during. dry season by the garbage the separate system is suitable where separate outlet for a strong water is available and the topography is such that the storm water can be disposed of in natural next is the combined sewerage system in this system the seaways and storm water are carried combined in one set of sewers to the wastewater treatment plant so combined sewer it is easy to clean Combined sewer because of their large size, this large size so it is easy to clean. The maintenance cost is reasonable as it requires one sewer and it reduces strength of sewer by mixing strong water with.
sewer because this is not separated only one sewer is used for storm water as well as for domestic seaways so it reduces the strength of seaways by mixing storm water then the disadvantage is in a strong seasons water may overflow and the sewer may damage causing serious health risk because the load is higher in rainy season that's why the possibility of damages more And so the chances of leakage is more and it causes serious health risk. The combined sewer gets silted and become foul in dry seasons. The load on treatment plant is high because both type of water are combinedly come to treatment plant and the system is uneconomical when pumping is needed.
So these are some advantages as well as disadvantages of combined treatment plant. there are partially separate sewerage system in this case the seaways and storm water of buildings are carried by one set of series while the storm water from roads street pavement are carried by other type of series it also have some advantages and disadvantages but the main advantage is that it combined the good features of both type of series means separate type of series as well as combined type of series so it have good feature of both the previously discussed type of seaways the setting is avoided due to entry of storm water and the storm water from houses is easily disposed of but the main disadvantage is very small of bad feature of combined series are there is partially separate system so only this is the disadvantage but this is more preferably type of series partially separate sewer now come on the Removal and disposal of human waste. What is human waste or human excreta?
Actually this is a waste type used to refer to byproduct of digestion such as faces and urine. So there are many different ways in which human waste can be collected, treated, disposed or reused. Starting with the type of toilet that is being used.
So in developing country resorts to open defecation for lack of other options where the human waste is deposited in the environment while others can use flood toilets where the human waste is mixed with water, transported and treated in sewage treatment plant. Children's excreta can be disposed or in diapers in responsible solid waste but on a worldwide scale it is also often dumped into the environment leading to public health so the human health hazard just because of contaminated seaviews is high it causes viral and bacterial diseases it can be a serious health hazard if it gets into sources of drinking water according to who report nearly 2.2 million people die annually from disease caused by this contaminated water so the health is out of improper disposal cause soil pollution water pollution contamination of food and propagation of flies there are different method of processing of the sea waves depends on the type of human wastage if it is sea waste then sea waste treatment plant if it's sea waste sludge then it goes into the sea waste sludge treatment plant and if it is a fecal matter from dry toilets then it may undergo This is the data about the global distribution of deaths from sanitation. This is a very recent data taken from the Hannah Ritchie and Max Roser to 2020 sanitation online at our world.
So, this is a recent data. It tells us that unsafe sanitation is responsible for approximately 775,000 deaths each year. This is the recent data that says that 775,000 deaths each year just because of unsafe sanitation still now and 5% of deaths in low income country result from unsafe sanitation. 2.4 billion people means one third of the world does not have access to improper sanitation and 4.5 billion people that means 60% of the world do not have access to. safely managed sanitation.
This is the map that show the degree of threat just because of improper sanitation in different countries over the world. 15% of the world still practice open defecation. 40% of the world does not have access to basic hand washing facility. And unsafe sanitation has a significant impact on childhood standing.
This is the case of world. So there are different definitions or different terms that defining this like improved sanitation facilities. Safely managed sanitation facilities and the basic services means limited services means improper services.
Basic services means private improved facility which separates excreta from human contact. Limited services means improved facility shared with other households. No services means open defecation. There is no services of in case of India still now.
this is the recent report of unicef unicef i have taken a recent reference 2020 reference india has the largest number of people close to 594 million that means 48 percent of population of india is still practicing open defecation this is the report of unicef 44 percent mother this exposing their child faces in open. There is a very high risk of microbial contamination like bacteria, viruses, amoeba, water which causes diarrhea in children. Children's weakness by frequent diarrhea episodes are more vulnerable to malnutrition, stunting and opportunistic infections such as pneumonia and about 48% of children in India are suffering from some degree of malnutrition. So still in India there are 48% of population that practices open defecation and 44% mothers depositing their child feces in the open.
Although this sanitation facility in rural India is improving but the increase is not equitable. Open defecation is still almost universal among the poorest 20% of the population. Even now, women and girls face same and a loss of personal dignity and safety risk if there is no toilet at home.
They have to wait for the night to relieve themselves to avoid being seen by others. A very low proportion of the rural population in India uses improved sanitation facilities, means the facilities which ensures hygienic separation of human excreta from human. There are various methods of excreta disposals.
Broadly these methods are of two types, unseaworth areas and seaworth areas. Unseaworth areas are of two types. This includes service type latrines, non-service types and latrines suitable for camps and temporary uses.
So first we will discuss service type latrines that is the conservancy system. Then we will discuss non-service type. laterals like the sanitary laterals this include borehole laterals dug well or pit laterals water seal type of laterals that is prai or rca or sulap sochale and septic tanks are equiprivy and third is the laterals suitable for camps and temporary use like the shallow trench laterals deep trench laterals pit laterals borehole laterals and second one is the improved type of sanitation facility like a seaways seawater areas the water carries system and seaways treatment and the water water carries through the seaways and the seaways treatment include primary treatment secondary treatment and other tertiary or other treatments like the oxidation pond sea outfalls river outfalls or fever forming so these are some methods of excreta So, now come on the first thing that is the open field defecation system. This never be acceptable as a satisfactory system of excreta disposal but might be invitable in certain circumstances if there is only one option. But when there is inappropriate facility.
of sanitation then only open defecation area are set up in these situation clearly demarcated open defecation areas the principal half hyzen must be kept in mind and the method must be followed for a short period of time as short as period of time as possible then second one is the service type latrines or conservation system here the night soil is removed from by human agency using a bucket so we can say bucket toilet is coming under the service type latrine night soil is transported in bucket on the head or in night soil card manually to dispose site disposal may be done through dumping composting or burial by shallow trenching totally unacceptable human dignity and hygiene point of view. So it was recommended by Environmental Hygiene Committee in 1949 the services areas must be replaced by the sanitary latents. So the founder of Sulabh Sochale, Dr. B. Dubey also took up the issue in big way. He showed the way forward by almost revolutionizing the sewage disposal to eliminate human carriage of night soil and installing low cost sanitary lateran then another is the shallow trench laterans this shallow trench lateran is 30 centimeter wide and 90 to 150 centimeter deep its length depend on the number of fuses three to three point few five meter for hundred people so shallow trench means the depth is less compared to the Deep trench lanterns.
Advantage, it is rapid to implement and faces can be covered easily with soil. But the constant rate, limited privacy, short life and requirement of considerable space for some of the constraints. Fly breeding occurs if excreta is not covered with earth.
Trench lantern is similar to silo trench lantern but here the depth is more than the silo trench lantern. and it is approximately 0.8 to 1 meter wide and 3.75 meter long and 2 to 2.75 meter deep. Advantage is that it is cheap and quick to construct. No water is needed in operation.
It is easily understood by the community. But the constant is unsuitable where water table is high. So, at least two unstable to dig or ground is very rocky.
Often, order problem cleaning and maintenance of community then next thing is improvised deep trench latrine this type of latrine may be carried out by placing the seals fitted with mortified water closets the seeds are fitted with a water seal or blend pipe which is connected to a pipe leading to a trench this includes simple pit latrine or dugwell latrine simple pit latrine should be deep as deep as possible at least two meter in depth covered by a slab the soil is loose at least the top one centimeter of the pill should be lined to prevent collapse okay so this soil must be tightly packed firmly supported by all the sides okay from all the sides firmly supported by all the sides and the super structure can be made from the material available locally Advantage is that it is cheap, quick to construct, no water needed for the operation. Whereas constant it is suitable where water table is high. While it is too unstable to dig or ground is very rocky. Often udder.
Improvised pit or VIP that is the ventilated improved pit latrine. So VIP type of latrine or improvised pit type of latrine or ventilated improved pit type of latrine is designed to minimize udder and flies so here the vent pipe is present just to avoid the udders proper ventilation through air flow is possible a vent pipe covered with a gauze mess or fly proof netting extending at least 0.5 meter above the superstructure roof is incorporated air should be able to flow freely through the square hole to vent pipe advantage at reduce udder and flies and good result and constant is difficult and expensive and time consuming to construct properly dark interior may deter young children from use does not deter mosquitoes then next is the borehole lettering borehole as the name suggests uh it is most appropriate in situation where a large number of lateral must be constructed rapidly and where pits are difficult to excavate so the bore well has a typical diameter of 400 mm and depth to pipe 2 10 meter at least the top 0.5 meter should be lined okay type 0.5 meter should be lined and it must be 5 to 10 meter long advantages the borehole can be excavated quickly and suitable in hard ground condition and appropriate where only a small workforce is available constant drilling equipment is required there is a greater risk of groundwater pollution due to the greater depth life span is next is pore pore plus latrine or water seal latrine this type of latrine is very hygienic model of excreta disposal it functions on the principle of water advantage lacto-abode relatively less water is used up and ideal where water is used for anal cleaning easy to clean construct Solid NL cleaning material may cause blockage more expensive than simple pit. So the water seal laterals are of two types.
First one is the PRAI type evolved by the Planning Research and Extension Institute Lucknow and the RCA type designed by the Research Come Action Project. RCA means Research Come Action Project. In Environmental Sanitation of Ministry of Health, PRAI means P for Planning, R for Research.
A for action and I for insured. So PARI is for the planning research and action insured Lucknow. So water seal latrine is made.
RCA latrine here the RCA latrine have the following features location, squirting plan, plant, trap, connecting pipes, drug wells, superstructure and maintenance. So the trap holds water and serves as a water seal. The depth of the water seal is 2 cm.
The trap is connected to the pit through connecting pipe. An appropriate superstructure can be made. It is easy to maintain the latrine. Latrine hand flush by pouring 1 to 2 liter of water every time the latrine is used.
And the squaring plate should also be washed clean every day. Water seal prevents excess to flies and avarice. Next thing is septic tank.
This septic tank is ideal system for hygienic final disposal of excreta in absence of the central sewer system. It designed to collect, treat excreta and toilet waste water. Best suited to single household or a group. Features of septic tanks Capacity-The minimum capacity of septic tank should be at least 500 gallon. The length is usually twice the breadth.
means it is greater in length than the breadth. Depth the depth of a septic tank is 1.5 to 2 meter. So this is the 1.5 to 2 centimeter depth of septic tank.
The recommended liquid depth is 1.2 meter. Okay air spaces minimum air space is 30 centimeter between the level of liquid in the tank and underwater surface is covered. The bottom is slopping toward the inlet means if this is the inlet the slopping toward the inlet. Covered the septic tank is covered by the concrete slab or of suitable thickness and provided with a main hole.
And the septic tanks are designed to allow a retention period of 24. Function by biological process of aerobic and anaerobic digestion. The crude sewage on entry of anaerobic chamber allowed to stand for 2 to 3 days. The effluent loses must of its offensive smell and the minerals are absorbed from the soil by the plants. Maintenance is simple.
Septic tank maintenance is simple. To commission septic tank it has to be first filled with water and then seeded with the bucket full of slush from the another tank. Not less than 25 liter of water per day per user must enter the tank.
So there is limitation of use of water. Use of soap water and chemical should be avoided. Slug from the tank is to be bailed out once in a year or two. And the simple rule is to dislodge from solid occupy between one half and two third of the total depth between the water level and water out. Next is the communal aqua pribe.
It is a type of latrine constructed directly above the septic tank. Then another is sulap sochale. The concept was introduced by Dr. B. Dhube. He modified the standard hard flesh lateral in suit rural Indian community.
It consists of especially designed pan and water seal trap. It is connected to a pit 3x3x3 pit. Minimum water is needed in this process and excreta get decomposed to manure in a pit.
This provide clean and sanitary toilets to user at a then another is a chemical toilets like this water carriage system useful for the large redis ncl and commercial area the human excreta and wastewater are carried away by network of underground pipes called sewers to ultimate disposal used water carriage system means the sewer first time used in calcutta in india 1867 this is very important point must be noted the sieves water carriage sewage system used first time in Calcutta in India in 1867. But even today unfortunately not more than 20% of urban areas in India can boast of this method of sewage disposal. Laying down such a system in infrastructure and capital intensive. Digging up lanes and by lanes. Skilled manpower is a must to establish the system.
and the ideal system of cphd exposure is in the another concept is the green toilet concept green toilet concept research design and standard organization a green toilet may be defined as a toilet which discharges effluent according to the environmental norm so the question arises in our mind what is green toilet it is green in color or it has something related to the plants no green toilet system means the toilet which discharges effluents according to the environmental norms this system is also known as environmental friendly toilet system efts and there are two types of efts first one is the biotoilet system and second is the zero discharge toilet system so what is biotoilet system a biotoilet system human waste is converted into liquid and gases and the gases get mixed with air and liquid is stored on the track in the zero discharge system solid and liquid waste is separated using a special topic of solid liquid separator and the liquid is recycled after proper treatment and waste is converted into manure so this is the con so in last slide the important points to be remember First thing effective and hygiene disposal of excretor is a social need as well as the health need. Second open defecation might still be a preferred method in many rural areas. In the areas without sewage system simple pit laterans and borehole can be used but the pore flush lateran is the ideal. So in rural area we can use simple pit type of lateran or borehole type of lateran. but the best option is the pore plus latrine trench latrine can be used for cams for short duration septic tank is also a suitable method for final disposal of night soil so this is the combination of population group with most suitable method of serious disposal if there is a joint family in village then the best method is the biogas plant if there is a large city then there is application of water carry system is the proper sewage system that where the sewage is carried out to the water through a manhole if there is a group of 20 household then the septic temp is a suitable option if there is temporary camp then we can plant a trench latrine and if there is a family in town then we can implant a pore flash net so this is all about your And last thing is the water carriage system depending on the type of material or sludge whether it is sludge or sewer and then it goes into the combined sewer system and separates.
These are the household sanitary fittings. Household sanitary fittings are of two types Indian squatting types and the western commode type of system. Thus aim of sea waste treatment is to stabilize the organic matter so that it can be disposed of safely and to convert the sea waste water into effluent of an acceptable standard of purity which can be disposed of into lands, river or sea.
And we can check the strength of the sewage or quality of the sewage by biological oxygen demand, by CO2 chemical oxygen demand or the suspended solid present in that. This is all about today's lecture on sewage sanitary engineering. Hopefully this will help you in your examination.
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