Fish farming is a best work from home and earn to your daily income from home. This is agriculture technical is and how to grow and this pratical few part of field.

1. Social outreach and skill development
BIO FLOC FISH FARMING
PROJECT REPORT
M.Sc. Chemistry 2nd semester
Session 2021-2022
Name – Raju lakra
Class- M.Sc.Chemistry
2nd Semester
Roll no.-20
Shri Sai Baba Aadarsh Mahavidyalaya Ambikapur, (Surguja) (C.G.)

2. CONTENT
•Executive summary
A.Brief description of syllabus
B.Venue (krishivigyan Kendra Ambikapur)
C.Teachers involved
D.Day of social outreach
•Introduction
• HISTORY
A.Introduction to fish farming
B.Introduction to biofloc fish culture
C.Fish feed
D.Need for biofloc technology
E.Composition and nutritional value
F.Principle
G.Species suitable for biofloc technology
H.How BFT works
I.Steps of fish farming
J.Methods of fish farming
K.Growth performance in biofloc system
L.Fish health
M.Preventing fish diseases
N.Reproduction
•Harvesting and Post harvesting
•Advantages and disadvantages
•Result and discussion
•Conclusion
•Appendix 1: overview of widely cultured fish species in surguja(ROHU, CATLA, TILPIA, CATFISH)
•Appendix 2: sources of information
•Reference

3. A. Executive summary
--Brief discussion of syllabus
In the syllabus of MSc 2nd semester chemistry paper number 4 we have social outreach and skill
development, and for the completion of this subject we need to make this project on the basis
of our skill development training under the supervision of our professors.
--Teachers involved
We had visited krishivigyan Kendra under the supervision of some professors from our college
that is
1 Miss Geeta Chauhan
2 Mrs. Rekha Haldar
3 Mrs. Kanchan Sahu
4 miss Chandni byapari
5 Mrs. Vibha Tiwari
6Mr. S K dewangan
7Mr. Deepak Tiwari
8 Mr. Arvind Tiwari
9 Mr. LP Gupta
10Mr. Abhishek Gupta
Divided into two groups for 2 days visits.
The trainer for our bioflock fish farming culture is named asVirendra tigga sir, he belongs to
krishivigyan Kendra.

4. --Venue ( KRISHI VIGYAN KENDRA)
The KrishiVigyan Kendra is a district level Farm Science Center established during
1995 by the Indian Council of Agricultural research (ICAR), New Delhi at Indira Gandhi
KrishiVishwavidyalaya, Raipur, Chhattisgarh for speedy transfer of technology to the
farmers fields. The operational area of this KrishiVigyan Kendra comes under the ICAR,
Zone IX, JNKV, Jabalpur (M.P.). The aim of Krishivigyan Kendra.....

5. Days of social outreach
Day 1 : knowledge about biofloc fish farming
After visiting krishivigyan Kendra, we will taught about what is
bioflock fish farming and the conversion of fish waste into the fish feed that
also save money and pollution. We were also told how the bacteria is
introduced to the fish waste and they converts it into useful feed. We were
also told why fish farming is done that is a side income source for the
farmers as people are so much interested into buying fish and eating
them.

6. Day 2: Field work and visit

7. B. INTRODUCTION
[1]History of Fishing in India
Fishing in India is a major industry employing 14.5 million people. India ranks
second in aquaculture and third in fisheries production. Fisheries contributes to 1.07% of
the Total GDP of India. According to the National Fisheries Development Board the
Fisheries Industry generates an export earnings of Rs 334.41 billion.[1] Centrally sponsored
schemes will increase exports by Rs 1 lakh crore in FY25. 65,000 fishermen have been
trained under these schemes from 2017 to 2020. Freshwater fishing consists of 55% of
total fish production.
The first BFT was developed in 1970s at Ifremer-COP (French Research Institute for
Exploitation of the Sea, Oceanic Center of Pacific) with Penaeusmonodon,
Fenneropenaeusmerguiensis, Litopenaeusvannamei and L.
[2]Introduction to fish farming
Fish farming or pisciculture involves commercial breeding of fish, usually for food, in
fish tanks or artificial enclosures such as fish ponds. It is a particular type of aquaculture,
which is the controlled cultivation and harvesting of aquatic animals such as fish,
crustaceans, mollusks and so on, in natural or pseudo-natural environment. A facility that
releases juvenile fish into the wild for recreational fishing or to supplement a species’
natural numbers is generally referred to as a fish hatchery. Worldwide, the most important
fish species produced in fish farming are carp, catfish, salmon and tilapia.

8. [3]Introduction to biofloc fish farming culture
High productivity and sustainable fish farming is the need of the hour in the
fisheries industry. Price, pollution in water and preventing disease outbreaks are some
of the challenges which need to be resolved. Biofloc fish farming is one of the best
available methods today which is helping fish farmers to attain a wide range of
objectives such as high output, low cost, sustainable growth, better income
opportunities, less area, less maintenance cost etc.
[4]What is Biofloc Fish Farming?

9. Biofloc technology is a technique of improving the quality of water by
balancing carbon and nitrogen in the system. The main purpose of Biofloc is to
recycle nutrients by converting unused feed and waste organic matter into food
using probiotics and carbon sources. It was developed as a substitute to open
pond fish farming and to prevent the introduction of diseases into the water. It is
an initiative that is not only cost-effective but also sustainable and
environmentally friendly. In India, the population is increasing every day and the
demand for aquaculture is also increasing with it. India contributes to over 6% of
global fish production. But the expansion of aquaculture is circumscribed mainly
because of the two reasons, first, as it put pressure on the environment by
discharging waste materials into the water bodies, and second, because of the
dependence on fish oil and fish food. Biofloc technology works as a solution to
these issues as it is a profitable method of intensive fish farming because it
controls the water quality and produces proteinaceous feet in situ. The
acceptance of Biofloc technology in outdoor and indoor systems has been well
documented and indoor culture tests have shown significant differences in terms
of production and productivity.

10. [5]FishFeed
In traditional fish farming methods, fish consumes very
little amount of feed supplied to them in the water. The wasted
feed pollutes the water and affects the surrounding environment
with the stench it emanates as well.
The feed is an essential part of fish farming. Every day a regular
amount of feed is necessary for the growth and development of
the fish. Acquiring feed is expensive and the wasted feed is thus
a loss for farmers.
In Biofloc fish farming system, wasted feed as well as fish excreta
in the water ecosystem, is converted into the feed which can be
consumed by the fish. The combination of microorganism, fungi,
algae etc. forms a biofloc which absorbs inorganic waste and
enhances water quality. The problem of water pollution is thus
solved in thismanner. Moreover, the fish farmers can save money
on feed and it is readily available as well.

11. [6]Need for Biofloc technology:
The growing demand for fish can not be fulfilled by using the
traditional methods of fish farming. Biofloc comes here as a cheap
and affordable technology. It converts the toxic materials into useful
products and acts as a retention belt for nutrients in the pond and
reduces maintenance costs.
Biofloc technology reduces water pollution and the risk of
introduction and spread of pathogens. Biofloc technology reduces
the utilization of protein-rich feed and the cost of standard feed and
increases productivity. This technology works best with species that
can derive the nutritional advantage from the direct consumption of
frock and who can tolerate high solids concentration in water and
are generally tolerant of poor water quality. Biofloc technology
keeps the water quality high and results in a great production of fish.

12. [7]Composition and nutritional value of biofloc
Biofloc is a heterogeneous aggregate of suspended particles and variety of
microorganisms associated with extracellular polymeric substances. It is
composed of microorganisms such as bacteria, algae, fungi, invertebrates and
detritus, etc. It is a protein-rich live feed formed as a result of conversion of
unused feed and excreta into a natural food in a culture system on exposure to
sunlight. Each floc is held together in a loose matrix of mucus that is secreted by
bacteria and bound by filamentous microorganisms or electrostatic attraction.
Large flocs can be seen with the naked eye, but most of them are microscopic.
Floc size range from 50 – 200 microns.
A good nutritional value is found in biofloc. The dry weight protein ranges
from 25 – 50 percent, fat ranges 0.5 – 15 percent. It is a good source of vitamins
and minerals, particularly phosphorous. It also has an effect similar to probiotics.
The dried biofloc is proposed as an ingredient to replace the fishmeal or soybean
in the feed. The nutritional quality is good; however, only limited qualities are
available. Furthermore, the cost-effectiveness of producing and drying biofloc
solids at a commercial scale is a challenge.

13. [8]Principle
The principle of this technique is the generation of nitrogen cycle by maintaining
higher C: N ratio through stimulating heterotrophic microbial growth, which assimilates
the nitrogenous waste that can be exploited by the cultured spices as a feed. The biofloc
technology is not only effective in treating the waste but also grants nutrition to the
aquatic animal.
The higher C : N is maintained through the addition of carbohydrate source
(molasses) and the water quality is improved through the production of high quality single
cell microbial protein. In such condition, dense microorganisms develop and function both
as bioreactor controlling water quality and protein food source. Immobilization of toxic
nitrogen species occurs more rapidly in bioflocs because the growth rate and microbial
production per unit substrate of heterotrophy are ten-times greater than that of the
autotrophic nitrifying bacteria. This technology is based on the principle of flocculation
within the system.

14. [9]Species suitable for Biofloc Culture
Major cultivable fish species in BFT. A basic factor in designing a biofloc
system is the species to be cultured. Biofloc system works best with species that
are able to derive some nutritional benefits from the direct consumption of floc.
Biofloc system is most suitable for species that can tolerate high solids
concentration in water and are generally tolerant of poor water quality. Some of
the species that are suitable for BFT are:
*Air breathing fish like Singhi (Heteropneustesfossilis), Magur (Clariasbatrachus),
Pabda (Ompokpabda), Anabas/Koi (Anabas testudineus), Pangasius
(Pangasianodanhypophthalmus)
*Non air-breathing fishes like Common Carp (Cyprinuscarpio), Rohu
(Labeorohita), Tilapia (Oreochromisniloticus), Milkfish (Chanoschanos)
*Shellfishes like Vannamei (Litopenaeusvannamei) and Tige Shrimp
(Penaeusmonodon)

15. [10]How BFT works?
Biofloc system is a wastewater treatment which has
gained vital importance as an approach in aquaculture.
The principle of the technique is to maintain the higher C-
N ratio by adding carbohydrate source and the water
quality is improved through the production of high quality
single cell microbial protein
In such condition, heterotrophic microbial growth occurs
which assimilates the nitrogenous waste that can be
exploited by the cultured species as a feed and also works
as bioreactor controlling of water quality.
This technology is based on the principle of flocculation
within the system

16. [11]Steps of Biofloc Fish Farming:
Step 1: Setting up the tank:
The first and foremost thing which is to be done is to find a perfect place
for the tank or pond in which the cultivation would take place. This could be a
bit tricky if you aren’t mindful of the subtle factors responsible for the growth
like the position of the sunlight, temperature of the place, ventilation of the
place, etc. But for the most part, it comes in with the experience and the
mastery of the craft as and when time surpasses.
All the above-mentioned things have an effect either negligibly but truly,
but here comes the takeaway: If you’re planning for a pond then make sure that
it should be lined with some protective layer such that there’s no influence of
soil on the water content. This is because of the fact that the major
contaminants come from the bed of the pond, as the soil is rich in heavy metals
like Arsenic, Methyl Mercury, Selenium, and cadmium, and sometimes soil also
contains remnants of fertilizers.

17. Step 2: Aeration
So, if you’re done with the above procedures properly, we shall move onto the next
and extremely important step i.e.
installation of aerators. Aerators are the components of the system which
are responsible for maintaining the entropy of the suspended particles of algae,
bacteria, protozoa, etc. which are the food for the fish and it also maintains the
optimal oxygen distribution throughout the tank/ pond in order to prevent the
formation of anaerobic zones which promotes the formation of methane and
ammonia.

18. Alright, so are you done with the above step. If yes is your answer then we
shall proceed further to the next and another major step that is the ‘selection of
species’. Though it has been seen that almost every other species of fish can be
cultivated using Biofloc, thanks to the improved culture water quality, but there
are a few species like those of catfish and Barbs which it has been found out that
these face difficulties in thriving in the culture water due to the high solid
suspended particle content which make the water too murky for the to
effectively grow. So, what’s the solution then? It’s fairly simple!
We’d like to have a species that is the most biologically efficient species for
that particular culture, water, and conditions. Now, how do we do that? The
answer is the Internet! There are data based on all the above parameters,
readily available on the internet and it would barely take a few clicks to find your
perfect match. So now that you’ve selected the best possible species for your
farm, it’s our duty to be a bit conscious about what our guests would have in
their meals, but in a very scientific manner.
Step 3: Selection of species and other related stuff:

19. Step 4: Optimization of Carbon and Nitrogen:
Not getting into the scientific depth, let us just skim through the optimization
part. There is a minuscule problem of ammonia peaks into the system if something
goes wrong like for e.g. one of the aerators has ceased to work. In these kinds of
scenarios due to the sheer nitrogen content, the formation of ammonia can take place
and if that remains the case for a long time it could turn into a nightmare for your flocs
and fishes. The carbon in these carbohydrates lets the heterotrophic bacteria multiply
and synthesize ammonia, thus maintaining water quality.
So again, optimization of carbon is also a significant thing to deal with. Let’s see
what experts have to say for the same. “We advise that you select only carbon sources
and feed mixtures with a carbon-to-nitrogen (C/N) ratio above 10 as this favors the
growth of these heterotrophic bacteria. Since most fish and shrimp feeds have a C/N
ratio of 9:1 or 10:1, additional inputs are needed to raise this ratio to between 12:1
and 15:1.
Any material that contains simple sugars and breaks down quickly can be used,
such as molasses, cassava, hay, sugarcane, or starch. Another solution is to reduce the
protein content of the used feeds.” To prevent ammonia peaks at later stages of the
production process, this step should be repeated, especially when using high stocking
densities in combination with large amounts of artificial feeds. Controlling this is one
of the hardest steps for successfully implementing Biofloc principles.

20. Step 5: Biofloc growth
: Now that the genius inside of you has managed to crack down the
above steps, let’s delve into the realm of Biofloc growth. So, until now we’ve
set up all things in possibly the best way. Now the time has arrived to start
with our cultivation. We’ll be planting the seeds for different algae, bacteria,
protozoa into the culture water with a few probiotics to amp up the process,
and within a matter of weeks the number of flocs would reach from almost
negligible to four to five flocs per milliliter. You’d be thinking that “what’s the
big deal here, this is quite gettable”, right? You’re absolutely right until you’ll
find out the progress of the next couple of weeks or so. This is the power of
exponents. Within a matter of days, the floc number would wreak havoc and
grow blazingly fast as if a nuclear fission reaction would’ve instigated. And
guess what, you’re now at about 10 billion bacteria per cubic centimeter of
the culture water. isn’t that amazing? Surveillance of the growth of these flocs
can be done by using a cone-shaped beaker or a flask for that matter, to
collect several water samples at a depth of 15cm to 25cm, preferably in the
late morning. The solid particles should be left to settle for 20 minutes. They
will stick to the sides of the cone-shaped beaker, making it easy to count
them.

21. Step 6: Monitoring and control of biofloc development
From this point on, water samples must be regularly taken to
monitor the pond water and determine the activity of the two
biofloc types plus their respective densities. In simple terms,
outdoor bioflocs consist of green algae and brown bacteria: the
algae mainly utilise sunlight for their growth, while the bacteria
mostly consume leftover feeds, their byproducts and associated
wastes.
Since algae initially tend to multiply faster, this means that a
pond looks green at first, turning brown over the following weeks
as bacterial colonies start to dominate. With the stock growing and
feeding volumes increasing, a tipping point will be reached wherein
the water will remain brown. As Nyman Taw explains: “This brown
color is more quickly reached with tilapia as they are fed with more
feeds, while it takes a bit longer with shrimp.”

22. Step 7: Monitoring and control of water parameters
and associated farm infrastructure
Once the biofloc system has turned brown, aeration must be
significantly increased to sustain the high respiration rate. As
shown in Figure 4, respiration rates at this stage can reach 6mg per
liter per hour, requiring up to six times more energy per hectare
compared with the start of operations.
Any power failure at this stage can quickly result in total crop
failure due to a lack of oxygen and because in a low-oxygen
environment many heterotrophic bacteria actually start producing
ammonia. It is vital for the aeration system to stay functional at all
times.

23. Step 8: Monitoring, Harvest, and Clean-up:
Water samples must be regularly taken to monitor the pond water and
determine the activity of the two Biofloc types plus their respective densities.
With the stock growing and feeding volumes increasing, a tipping point will be
reached wherein the water will remain brown. Once the Biofloc system has
turned brown, aeration must be significantly increased to sustain a high
respiration rate. Good maintenance and monitoring of the aerators
themselves, plus the power system that provides the energy to run the
system. Regular monitoring of water quality parameters, especially dissolved
oxygen and ammonia levels, will give an idea if the system is working
well.After following the steps a farmer can notice the change in the cost and
profitability. Proper cleaning and preparation of the pond setup for the
raceway is important after harvest time. After some time heavy metal can
build up in the culture water which can make the stock answer table for
consumption. Thus, cleaning up well before starting your next profitable batch
is necessary.

29. [12]Growth performance in Biofloc system:
The performance of aquatic animals in a Biofloc system is analyzed by the
following parameters, such as the growth of fishes based on length and weight
at intervals of every 15 days. You can analyze by weighing 10 fish from each
treatment that replicates randomly. Fishes have to starve overnight before
checking their weight.
[13]Fish Nutrition
There are usually two types of food available to the fish: natural and
Supplementary. Natural fish food consists of phytoplankton, zoo plank-Ton,
periphyton, water plants, etc. produced in the pond itself. Sup-Plemontary fish
feed is produced outside the pond and supplied to the Fish regularly to further
increase the amount of nutrients in the pond.

30. [14]Fish Health
Fish are vulnerable to diseases when environmental conditions, such As water
quality and food availability, are poor. Once a disease has Entered the fish pond it will be
very difficult to eradicate it. This is Because infected fish are difficult to pick out and treat
separately. Water is a perfect agent for spreading diseases. The diseases from which Fish
may suffer are many and varied. Sick fish do not grow, so the Farmer loses money as
harvest is delayed. If fish are near market size When they die from disease, losses are very
severe.
[15]Preventing fish diseases
Good nutrition and proper water quality (= plenty of dissolved oxygen) are the most
important factors for good fish health. Many of the potential pathogens (organisms
which can cause disease) of fish species are normally present in the water waiting to
‘attack’ when environmental conditions become bad. Under such conditions the fish
become stressed and their resistance to diseases is lowered. There are some basic rules
to be observed in order to prevent, or control, disease outbreaks:

31. 1 Ponds must have separate water supplies. It is not advisable to supply a pond
with water from another pond, since this water may carry diseases and the level
of dissolved oxygen may be low. It is therefore wise not to design ponds in series.
2 Fish must be kept in water with optimum conditions at all times: water with
plenty of oxygen, with the correct pH and with a low ammonia content.
3 Fish must not get stressed. If you handle the fish, take great care so that you
upset them as little as possible. Extreme stress can be the direct cause of fish
death. Damage to their skin (rubbing off the scales and the protective slime
layer), means pathogens can enter the fish more easily.
4 Great care must be taken that no sick fish are introduced when mixing fish
from different ponds, or when introducing new fish into the farm. New fish to
the farm site should be kept in a separate pond until it is certain that they do not
carry a disease.
5 Any change in normal behavior may be a sign of disease. Signs to look
for include gasping at the surface for air, rubbing the body or head against
the sides of the pond, or ragged fins

32. C. Harvesting the fish
As in any other type of farming the final phase in the fish
farming cycle is the harvest and possible sale of the fish. When
most of the fish Are big enough to be eaten or sold harvest can
start (usually after 5 to 6 months) but harvest only what can be
eaten or sold within one day. At harvest, start emptying the pond a
few hours before dawn while it Is still cool. There are two ways to
harvest fish: either take out all fish In the pond at the same time or
selectively cull fish from the pond Throughout the whole year. In
the latter method, usually the larger fish Are taken out and the
smaller fish are left in the pond to grow on. It is, Of course,
possible to combine these two methods by taking out large Fish as
required and finally removing all the remaining fish at one Time.
There are different kinds of nets with which you can harvest the
fish.

34. D.Post harvesting
After harvesting, the pond is dried until the pond bottom cracks and Limed (reducing
pond bottom acidity) thereby killing unwanted animals and plants on the pond
bottom. Some more simple, and therefore cheaper, nets are: A lift net made of seine
netting material. It can be of Any shape and size and is set on the pond bottom. When
the fish Swim over it, it is lifted up, capturing the fish. A scoop net is a small net with a
handle that is held in One hand. It is often used when counting and weighing fish and
fingerlings. A cast net is a round net that is thrown into the pond From the shore and
pulled back to capture the fish.
E.Advantages of Biofloc technology:
• Reliable and profitable method of farming.
• Minimize water exchange and water usage in the aquaculture system.
• Produce low-cost Bioflocs, rich in protein.
• Provide more economical alternatives and additionally a potential gain on feed
expenses making it less expensive.
• Biofloc systems maintain water quality by reducing water pollution and reduce the
introduction and spread of pathogens.
• Limited or zero water exchange.
• Biofloc systems use cheaper food fish and trash fish feed formulation.
• Biofloc system is an eco-friendly culture system that reduces the environmental
impact on aquatic culture.
• Improves land and water efficiency.

35. F.Disadvantages of Biofloc fish technology:
•Reduce response time due to water respiration rates are elevated.
• Seasonal and inconsistent performance for sunlight exposed systems.
• Alkalinity supplement required.
• Increase the energy requirement for mixing and aeration.
• Start-up period required.
• Increased pollution potential from nitrate accumulation.
• Increased instability of nitrification
G.Conclusion:
Biofloc can be considered as a budget-friendly innovative technology where the toxic
material is converted into the proteinaceous feed. Biofloc technology application does
offer good benefits in improving aquaculture production that could contribute to the
achievement of sustainable development goals.AlthoughBiofloc technology is still in its
infant stage it may be developed and performed in integration with other food
production, and does promote productive integrated systems, aiming at producing more
food and feed from the same area of land with fewer inputs. This technology could
result in higher productivity with less impact on the environment. Biofloc technology is
a green approach in aquaculture known in a different name such as zero exchange
autotrophic, single-cell protein production system, etc.

36. PHOTOGRAPHY

38. Appendix 1: Overview of widely cultured fish in sarguja
Catfish culture
Catfishes are popular for their taste, less muscular spines, small gut, medicinal
importance and some having air-breathing nature. They are preferred over other
fish species due to high quality fillets making properties for meeting export
demand. Around 3407 valid species of catfishes exist that share over 10% of global
fish diversity. Catfish farming is popular in Vietnam, China, India, USA, Indonesia,
Nigeria, Malaysia, Thailand and Bangladesh for meeting both home and export
demand.
Tilapia culture Tilapia is seasonal. It can survive and breed only in warmer
water. The ideal water temperature for a tilapia farm is 82-86 degree. Fish will start dying
below 55 degree, and you will see a drop in the growth rate. Hence, India is suitable for
tilapia farming.

39. Rohuculture
Rohu (Labeorohita) is the most important among the three Indian
major carp species used in carp polyculture systems. This graceful Indo-
Gangetic riverine species is the natural inhabitant of the riverine system
of northern and central India, and the rivers of Pakistan, Bangladesh
and Myanmar.
Catlaculture
Catla, the second most important species after rohu (mrigal is third), is used as
the surface feeder component in Indian major carp polyculture systems. In the six-
species composite system with rohu, mrigal, common carp, grass carp and silver carp,
catla shares the upper feeding niche of the pond with silver carp. In the three-species
system in India the proportion of catla stocked is usually kept at 30-35 percent, while
in six-species culture it forms 15-20 percent

40. Appendix 2:Biofloc fish farming in India
Different Indian states have started to use the biofloc system to enhance
fish/shrimp farming output, boost quality and help fish farmers gain more in the process.
Odisha’s Fisheries and Animal Resources recently announced the use of biofloc fish
farming technology for boosting aquaculture in Odisha. It requires much lesser space
than the traditional form of fish farming. According to experts an area of 150 to 200 sq-
ms along with sufficient water supply is enough to grow 2000 kg of fish in four small
tanks. A variety of freshwater fish species like tilapia, carp, magur, anabas, pangasius can
be reared easily.
Reference
1 https://rocketskills.in/blog/biofloc-farming-guide/
2 https://organicabiotech.com/biofloc-fish-farming-in-india/
3 https://acrobat.adobe.com/link/review?uri=urn:aaid:scds:US:b6662ecd-efa3-32a4-
adbf-e138b7dd3c9a
4 http://www.kvksurgujacg.org/
5
https://rocketskills.in/blog/biofloc-farming-guide/
6 https://www.agrifarming.in/types-of-fish-farming-methods-and-systems-in-
india#:~:text=An%20extensive%20fish%20farming%20system,(e.g.%20with%20animal
%20waste)

41. THANK
YOU
EVERYONE
Presented by- Raju lakra