Chapter 6 From the basic theories to practical application of composting technology
6

From the basic theories to practical application of composting technology

6.1

Preparing seed compost by culturing microorganisms

In order to produce high-quality compost in the shortest period possible while suppressing odors,
adjustment and management should be conducted with a focus on the three important items, namely the“microorganisms,” “oxygen” and “moisture content.” For starting composting smoothly utilizing diverse
organic wastes received as raw materials, it is effective to add high-quality microorganisms in the initialstage while maintaining appropriate moisture content and void ratio. The effectiveness should be felt morestrongly by those with little experience in composting.
Seed compost is produced by cultivating microorganisms, and a method for producing about 1 m3 of seed
compost is explained here. Explanations will be given separately for small-scale cultivation using ahousehold compost container and large-scale cultivation at a large-scale compost center.
6.1.1

Preparing a fermentation liquid

Two methods for cultivating a fermentation liquid are explained here, one using a sugar solution and theother using a saline solution. Different types of microorganisms are cultivated with each of the solutions, so
it is desirable if both types of fermentation liquid were prepared. However, preparation of both is not arequirement.
(1) Cultivation using a sugar solution
Sugar is a carbohydrate used by diverse microorganisms as a source of energy. As such, decaying could
result in that causes odors, if microorganisms not suited for composting (referred to as unwanted bacteriahere) were mixed. Here, fermented food products produced under hygienic management as foods we eat(see “4.1.1 The composting process is broadly divided into three stages”) are used.
[1] Steps for preparing a fermentation liquid
 Have a container with a capacity of about 20 liters ready.
 Dissolve 100 g of sugar in 15 liters of water, for preparing a sweet sugar solution.
 Put in and dissolve a fermented food product (yogurt, dry yeast, local wine or other products
available in the area).
 Close the opening with a plastic bag.
 The plastic bag swells when the bacteria are active and carbon dioxide gas is emitted.
 Fermentation is finished in about five to seven days; it is a success if sour-sweet, alcoholicaroma is felt, and a failure if an unpleasant odor is felt.

1© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Fig. 5-1: Preparing fermentation liquid using
a sugar solution

Photograph 5-1: Fermentation liquid isprepared using a sugar solution

Remarks:
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The fermented food products mentioned here are examples. The readers are advised toacquire as many fermented food products as possible that are available in the region. Thatwould enable more effective composting.
If the container was soiled, unwanted bacteria proliferate and cause decaying.
If there is a possibility of groundwater being contaminated, use the groundwater after
boiling.
The “refined sugar,” “brown sugar,” “molasses” and other types of sugar may be used.
The mixing ratio of sugar and water mentioned is for a reference; if the amount of sugar
were small, more time would be needed for the growth of microorganisms.
The disinfection effect of the chlorine in tap water is lost as soon as a fermented foodproduct is input into the liquid, so the microorganisms would not be extinct.
Proteins and other factors necessary for the growth of microorganisms are supplied fromthe fermented food products.
All of the fermentation liquid that was prepared should be used on the spot, as a principle.
However, it may be stored for several months if kept in a cool, dark place with goodconditions for storage. When reusing the liquid after storage, add sugar and leave for a few
days at a normal temperature for activating the microorganisms.

(2) Cultivation using a saline solution
When it is difficult to obtain a fermented food product, microorganisms floating in the air can be used.
Among the food products familiar in the traditional food culture of Japan are vegetables and other materials
pickled in rice bran and brine, with which lactic acid bacteria and yeast are at work. Since the lactic acidbacteria and yeast are resistant against salt, the growth of unwanted bacteria is suppressed by adding salt
and raising the salinity.
Drawing on the characteristics peculiar to lactic acid bacteria and yeast, they may be extracted selectively
using a saline solution. (See “4.1.1 The composting process is broadly divided into three stages.”)2© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[1] Steps for preparing a fermentation liquid
 Have a container with a capacity of about 5 liters ready.
 Dissolve 30 g of salt in 4 liters of water, for preparing a salty saline solution.
 Mix vegetable leaves, skins of vegetables and fruits, and flowers (nectar) into the solution.
 Close the opening with a plastic bag.
 Fermentation is finished in about seven days; it is a success if sour-sweet, alcoholic aroma isfelt, and a failure if an unpleasant odor is felt.

Photograph 5-2: Fermentation liquid isprepared using a saline solution

Fig. 5-2: Preparing fermentation
liquid using a saline solution

Remarks:
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6.1.2

Exercise utmost care to reduce the number of unwanted bacteria that is mixed, because
proliferation of unwanted bacteria is being suppressed, relying on the salt only. (Avoid
inputting damaged or rotten part of the vegetables and fruits.)
The amount of salt should be such that the resulting solution tastes like salty soup.
Decaying could progress if the amount of salt were small.
Clean seawater may be used after dilution.
Peel off the skin of vegetables and fruits relatively thick, because there is only a little
amount of energy source and proteins in the solution that are necessary for the growth of
microorganisms.

Preparing seed compost(1) Preparing base materialFirst, the home ground for cultivating microorganisms and their source of energy are prepared and mixed.

3© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[1] Materials of the home ground for the growth of fermentation bacteria:
Materials with a solid form that are hardly decomposed by microorganisms (having a relatively
high C/N ratio)
Rice hull, wood shavings, fallen leaves, humus, corn core, buckwheat husk, cut rice straw, etc.
[2] Materials serving as the source of nutrients for the growth of fermentation bacteria:
Low-priced ones among food products eaten by the humans or feeds for animals
Rice bran, wheat flour, powdered corn, powdered soybeans, bird feeds, etc.

Shown below are examples of the blending ratios for thebase material.
Rice bran : Rice hull = 1:1 to 1:5
Rice bran : Rice hull: Wood shavings = 1:1:1
Rice bran : Fallen leaves =1:1 to 1:5

Fig. 5-3: Preparing seed compost

Remarks:The materials for nutrition are purchased in many cases, so their mixing ratios may be
reduced to suit the circumstances.
If the mixing ratios of nutrient materials were small, a longer time would be needed for thegrowth of microorganisms, and the degree of growth of microorganisms becomes lower.
The prepared mixture is used as seed compost to be mixed with raw garbage. The raw
garbage may be used as a source of energy for cultivating microorganisms, if an aerobic
state is maintained by managing the moisture content, the aeration volume and agitation
frequency properly. In other words, microorganisms are cultivated using raw garbage.

Examples of base material (home ground)

Photograph 5-3: Rice hull

Photograph 5-4: Corn core4

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-5: Cut rice straw

Photograph 5-6: Peanut shells

Photograph 5-7: Sawdust

Photograph 5-8: Wood shavings

Photograph 5-9: Fallen leaves

Photograph 5-10: Humus

Examples of the (nutrient) base material include rice bran, wheat flour, powdered corn, powdered soybean,
and bird feeds; their photographs are omitted here.
(2) Mixing the fermentation liquid
Put in water, white bacteria found underneath fallen leaves, and mushrooms in a large container, add thefermentation liquid and mix well. If both types of fermentation liquids were prepared, they should bemixed.

5© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology(3) Mixing base material with fermentation liquid
Add the mixture of fermentation liquids to the base material, adjusting so that the moisture content would
be 40 to 60%. Adjust the amount of water when preparing the mixed solution in step (2), so that the entire
mixture solution may be added. However, moisture content adjustment is given priority, so not all of the
mixture solution should be added if the moisture content becomes too high. On the other hand, add water
when the moisture content is too low.

Fig. 5-4: Preparing seed compost(4) Completion of seed compost
Pile the mixture in a trapezoidal form, cover it entirely with an air-permeable cloth, and agitate the mixture
once every day or every other day. The highest temperature at the center should be managed to be between
about 60 and 80℃. If the temperature exceeds 80℃, the mixture should be spread for dissipating the heat.
The moisture evaporates as time goes by, but keep the mixture as is, without adding water. The temperaturedeclines also. The seed compost is usually completed in about a week. If white bacteria have proliferated
on the surface and cakes of seed compost have been formed by mold or other filamentous fungi, the seed
compost is complete. The completed seed compost should be stored in a dry condition, and used when a
new compost center starts operation or distributed to each family for household composting.

Photograph 5-11: The base material is being
prepared

Photograph 5-12: Fermentation liquid is mixed

6© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-13: Base material is mixed withfermentation liquid

Photograph 5-14: The mixture is covered andmanaged daily

Managed so that the highest temperature
would be between 60 and 80°C

Fig. 5-5: Temperature management for seed
compost6.1.3

Photograph 5-15: The seed compost is completed

Small-scale cultivation using household composting container(1) Cultivation using a sugar solution
Prepare a sweet solution of sugar as described in “(1) Cultivation using a sugar solution” in the section“6.1.1 Preparing a fermentation liquid,” and mix a fermented food product. It would be convenient to use aone-liter PET bottle as the container.
Fill the sugar solution to about 70% of the fullest capacity of the container. Close the cap loosely, because
carbon dioxide gas is emitted while the microorganisms are active. Fermentation is finished in about five toseven days; it is a success if sour-sweet, alcoholic aroma is felt, and a failure if an unpleasant odor is felt.
(2) Cultivation using a saline solution
Prepare a saline solution as described in “(2) Cultivation using a saline solution” of the section “6.1.1
Preparing a fermentation liquid,” and put in vegetable leaves, skins of vegetables and fruits, and flowers(nectar). It would be convenient to use a one-liter PET bottle as the container.
Fill the saline solution to about 70% of the fullest capacity of the container. Close the cap loosely, because
carbon dioxide gas is emitted while the microorganisms are active. Fermentation is finished in about sevendays; it is a success if sour-sweet, alcoholic aroma is felt, and a failure if an unpleasant odor is felt.
7© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

A white-colored membrane might be formedon the surface of the liquid using a sugar
solution. It is formed when aerobic bacteria
proliferated on the surface, and evidences thatthe fermentation is progressing well.

Photograph 5-16:
Fermentation liquid using saline solution andfermentation liquid using sugar solution(3) Preparing seed compost About 15 liters of ricehull
 About 200 g of rice bran
Mix well in a plastic bag

Materials that can replace rice hull:wood shavings, fallen leaves, humus,
corn core, etc.
Materials that can replace rice bran:
wheat flour, powdered corn, powderedsoybeans, bird feeds, etc.

 Fermentation liquid White bacteria foundunderneath fallen leaves
 Mushrooms
Mix them well

Mix all the materials in a plastic bag.
Adjust the moisture content to be between 40 and 60%. Add
water if the moisture content is low, and adjust the amount offermentation liquid added when the moisture content is high.

8© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Transfer the entire mixture to a container from the plastic bag,and provide measures to avoid insects.
Agitate the mixture once every day, and fermentation
would be complete in about seven days.

Note: See “6.2 Attempts at home – Household composting” for the ways to make a composting container.
(4) A method in which cultivation using a sugar solution or a saline solution is omitted
The purpose of cultivating microorganisms using a sugar solution or a saline solution is to increase thenumber of microorganisms used for fermentation. For example, lactic acid bacteria contained in a spoonfulof yogurt may be increased to about 15 liters. As can be seen, a large amount of fermentation bacteria may
be cultivated at a low cost.
On the other hand, it is burdensome to cultivate microorganisms in a PET bottle if composting was
attempted at home. If a seminar on composting was held for participants who are very much motivated, andif they were told to “come again six days later because five days are needed for cultivating microorganisms,”
some of them might be so disappointed and even lose their interest in composting.
For this reason, a method that does not involve cultivation using a sugar solution or a saline solution is
explained below. The method is very simple. Fermented food products contain a large number ofmicroorganisms, so such fermented food products are put in at a large amount.
 About 15 liters of ricehull
 About 200 g of rice bran
 About 50 g of sugar
Mix well in a plastic bag

Materials that can replace rice hull: woodshavings, fallen leaves, humus, corncore, etc.
Materials that can replace rice bran:
wheat flour, powdered corn, powderedsoybean, bird feeds, etc.

 Fermented food product (for example, 200 milliliters of yogurt,a package of dry yeast, etc.)
 White bacteria
found underneathfallen leaves
 Mushrooms
Mix them well9

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Mix all the materials in a plastic bag.
Adjust the moisture content to be between 40 and 60%. Add
water if the moisture content is low, and adjust the amount ofwater added when the moisture content is high.

Transfer the entire mixture to a container, and provide
measures to avoid insects.
Agitate the mixture once every day, andfermentation would be complete in about two days.

6.1.4

Large-scale cultivation at a large-scale compost center(1) Cultivation using a sugar solution
Prepare a sweet solution of sugar as described in “(1) Cultivation using a sugar solution” in the section“6.1.1 Preparing a fermentation liquid,” and put in a fermented food product. It would be convenient to use
a large container with a capacity of about 1 m3.
Fill the sugar solution to about 70% of the fullest capacity of the container. Close the cover loosely, because
carbon dioxide gas is emitted while microorganisms are active. Fermentation is finished in about five toseven days; it is a success if sour-sweet, alcoholic aroma is felt, and a failure if an unpleasant odor is felt.
(2) Cultivation using a saline solution
The workload becomes extensive when cultivation using a saline solution is attempted at a large scale, so
this step is omitted here.
(3) Preparing seed compost
Please prepare the materials necessary for making seed compost as appropriate. The following materials
were used for producing the example shown in the photograph.
 The nutrient materials such as rice bran for promoting growth of fermentation bacteria : Materials
such as rice hull for forming the home ground = 3:10
 The dilution ratio of the fermentation liquid made with a sugar solution by the water = 1:29
The amount of materials used in the example were 1.2 tons of rice bran, 4 tons of rice hull, 0.1 m3 ofdiluted fermentation liquid and 10 liters of fallen leaves from a forest; water was sprinkled as appropriate to10© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
keep the moisture content at about 50%, and helped by heat accumulation also, the fermentation wascomplete in about three days.

Photograph 5-17: Fermentation liquid is
produced using a sugar solution

Photograph 5-18: The conditions of fermentation
liquid is checked (based on the odor)

Photograph 5-19: Fallen leaves (ray fungi andother bacteria) were collected from a forest

Photograph 5-20: Fermentation liquid ismixed with water

Photograph 5-21: Fallen leaves are mixed
with the mixture solution

Photograph 5-22: The mixed fermentation
liquid is complete

11© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-23: A wheel loader was usedbecause a large amount of rice hull and ricebran was used as the base material

Photograph 5-24: The base material is being
spreadPhotograph 5-25: The mixed fermentation
liquid is sprinkled on the base material

Photograph 5-26: The base material is being
mixed

Photograph 5-27: The microorganisms
proliferated in about three days
White microorganisms are observed on thesurface

Photograph 5-28: The temperature rose above
60℃
Filamentous bacteria became tangled with thebase material and formed cakes

An extremely large amount of seed compost (150 tons, for example) is necessary for processing 50 tons of
raw garbage per day. If materials such as rice hull and rice bran may be obtained at a low cost, including
the transportation fees, the readers are recommended to cultivate and stock a large amount of seed compost.
If it is costly, think of the first attempt of composting as a period for acquiring the composting technique,12© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
keep the amount of raw garbage processed per day small, such as 5 ton/day, and use the entire compost
produced as seed compost (returned compost). In other words, keep the amount of seed compost produced
at the time of starting very small, and using raw garbage, produce a large amount of seed compost.
6.2

Attempts at home – Household composting

Raw garbage generated at home may be composted at home. Here, an explanation is given, assuming about
500 g of raw garbage is composted daily. Since the amount of raw garbage to be processed could vary eachday, the methods to deal with the varying amounts are also discussed.
6.2.1

Step 1: preparation(1) Have an air-permeable container readyFind a container for placing seed compost to start raw garbage composting (processing). An air-permeablecontainer should be used that can keep inside the compost in an aerobic condition all the time if possible,
because composting basically involves aerobic fermentation. A box made of various materials may be used,
including plastic, bamboo and corrugated board. Since the container needs to be lined, a square box is easy
to work with. In terms of durability, plastic containers are longer-lasting. Organic materials, such asbamboo, are decomposed by microorganisms. Corrugated board boxes are available at low prices, but they
are decomposed quickly and need to be replaced in about three months.

Photograph 5-29: Examples of air-permeable containers(2) Size of the container
The average amount of raw garbage generated at a household in Japan is about 500 g (1 liter) per household.
The amount of seed compost appropriate for the above amount of raw garbage is about 15 liters, based on
the author’s experiences. Considering the ease of agitation of the overall seed compost and assuming the13© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
period of raw garbage processing to be about three months, a container with a capacity of about 30 liters
would be necessary.

Amount of processed raw garbage : Amount of seed compost : Container capacity = 500 g (1 ℓ) : 15 ℓ : 30 ℓ
Based on the above ratio, the amount of seed compost and the container size should be adjusted to suit theamount of raw garbage generated. Here, please also consider the following points.
[1] If the amount of raw garbage generated is less than 500 g/day
The compost tends to become dry if the amount of seed compost was less than 15 liters. Think of the 15
liters of seed compost as the minimum amount in order to reduce the risk of failure.
[2] If the amount of raw garbage generated is greater than 500 g/day
The moisture content tends to become excessive, and odors are generated more easily, as the amount of
raw garbage to be processed increases. Therefore, the amount of seed compost should be increased at
the ratio of “raw garbage : seed compost = 500 g : 1 liter.” However, the air penetrates the compost for
only about 30 cm from the surface when the compost is kept in a standing condition. As such, themaximum dimensions of the container should be 60 cm  60 cm  60 cm (H).
However, larger containers are more difficult to handle because the amount and weight of seed compost
inside increases, and agitation would be more difficult. The readers are recommended to use several
containers of sizes that are easy to handle.
(3) Lining the container
The containers should be lined using a carpet or a thick cloth so that the seed compost in the container
would not fall out. Materials made of synthetic fibers are not decomposed by microorganisms, while cottonand other organic materials are decomposed by microorganisms and become damaged. The lining made oforganic materials needs to be replaced at some time. Corrugated boards may also be used, but they alsoneed to be replaced for the same reason.

Fig. 5-6: Methods of container lining

14© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology(4) Examples of container lining
Insects may be prevented more effectively if the container was firmly lined. Methods of lining using acarpet or a corrugated board are shown below, as examples. The container used is a plastic container with alid, which is shown as an example.

Photograph 5-30: Plastic container with a lid, capacity of 50 liters[1] Using a corrugated board for lining

Photograph 5-31: Cut the corrugated board
to fit the size of the container, and attach adouble-sided tape on the edges

Photograph 5-32: Align the container with thecorrugated board; there are allowances foroverlapping at the edges

Photograph 5-33: Bond the lining so thatthe edges are overlapped

Photograph 5-34: Completed lining15© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[2] Using a carpet for lining

Photograph 5-35: Prepare an expanded
drawing of the lining using a paper; secure
allowances for overlapping at the edges

Photograph 5-36: The carpet to be used

Photograph 5-37: Copy the expanded
drawing of the lining on the carpet

Photograph 5-38: Cut the carpet

Photograph 5-39: Attach a double-sided
tape on the edges of carpet

Photograph 5-40: Double-sided tape16

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-41: Bond with the double-sided tape,starting with the longer surface

Photograph 5-42: Bond with the double-sided
tape on the shorter surface

Photograph 5-43: Overlap the edges whenbonding, so as not to leave any gap

Photograph 5-44: Completed lining[3] Using cloth or newspaper for lining
It would be difficult to attach a corrugated board if the container is circular. A cloth or a newspaper should
be used for lining in such cases. When using such materials for lining, a wall-like portion may be formedby avoiding agitation of the seed compost at locations close to the container surfaces and keeping these
portions in a dry condition.
Wall-like portion of
the seed compost
Corrugatedboard

Seed compost

Lining the basket withcorrugated board

Put in the seed compost

Portions of the seed compost
close to the basket surfaces are
kept dry without agitating, forforming wall-like portions

Fig. 5-7: Wall-like portion should be formed when organic material is used for lining17© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-45: Example of composting
containers in the Philippines

Photograph 5-46: Example of a composting
container in Nepal

Photograph 5-47: Examples of composting
containers in Indonesia

Photograph 5-48: Example of a composting
container in Japan(5) Measures against soldier flies and other insects
Raw garbage compost always attracts insects. Soldier flies are highly reproductive, and larvae often
proliferate in containers. In order to prevent soldier flies from laying eggs in containers to the extent
possible, the containers should be closed with the lid or covered firmly, as shown in the photograph above.
On the other hand, there is a composting method known as soldier fly composting, in which the larvae eat
raw garbage and defecate. The feces make high-quality compost.

Old T-shirt

Sew along the dot line ( ),and cut along the bold line(
) on the outside

Turn inside out and place on thecontainer as a cap

Fig. 5-8: How to make a cap for protecting against insects18© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Fig. 5-9: Covering the container forprotecting against insects

Photograph 5-49: Covering the container forprotecting against insects(6) Place to store composting containers
It seems better to store composting containers indoor in order to prevent insects. No odor would rise if
composting is going well. If stored outdoor, choose a place not exposed to direct sunlight and rainfall.
Place the container on bricks or blocks, so that the bottom surface would not touch the ground surface
directly. (This way, the air permeability of the container is enhanced, an aerobic condition is promoted, andthe bottom surface is prevented from becoming wet.)

Balcony
Under theeaves

Storage

KitchenServiceentrance

GarageFig. 5-10: Places to store compost containers(examples)
6.2.2

Fig. 5-11: Keep the composting
containers air-permeable

Step 2: Putting raw garbage in the container

Chop raw garbage to small pieces, squeeze out excess water, place in the container and mix well. Steamed
rice easily forms a cake, so sprinkle water to loosen the cake before putting it into the container.
Then, cover the surface with seed compost so that the raw garbage is not exposed in order to prevent
insects.

19© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Chop raw garbage into small pieces,place in the container and mix well.

Fig. 5-12: Chop raw garbage into small pieces

Place seed compost in thecontainer

Mix raw garbage with seed
compostChop raw garbage into small pieces
and place in the container

Mix raw garbage further

Bury raw garbage in the basematerial

Photograph 5-50: How to use a composting container

6.2.3

Step 3: Completing the compost

When the mixture in the container has increased in volume, start preparing to use the mixture as compost.
Leave the seed compost placed in the container, and take out only the portion that has increased. This way,
the seed compost may be used repeatedly.

20© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

The increased
portionOnly theincreased portionis taken out
The initial compost
volumeIncrease in thevolumePlace in an air-permeable
corrugated board box or a
bag to start secondary
fermentation

Fig. 5-13: Taking out the compost
 If a difficulty was felt when agitating the compost, it is ready to be taken out.
 If the compost taken out was dry, add water as appropriate for adjusting the moisture content.
 Place the compost in an air-permeable cardboard box or paper bag.
 Mature the compost for two weeks or more, keeping the moisture content at an appropriate level, andthen the compost would be ready for use.
Why is secondary fermentation necessary?
Since raw garbage is put into the compost every day, the mixture contains raw
garbage that was put in yesterday and that placed inside a while ago. The secondary
fermentation is performed to bring the level of maturity of the raw garbage to asame level.

6.3

Attempts at compost centers

6.3.1

Merits and demerits of composting at compost centers

Composting raw garbage generated at a household at the household is one of the most reasonable methods
to process wastes, as the person is processing his/her own garbage at his/her responsibility. However, noteveryone who attempts composting ends up with success. Many cases of troubles have been reported, andmany questions have been sent in, such as “an irritable odor is felt,” “there is an outbreak of insects,” “theseed compost became too wet,” and “the raw garbage is not decomposed.” If no follow-up were provided
for troubleshooting or for dealing with the problem, the person would stop composting halfway. If ten
households attempted composting, there would be ten items that need follow-up. The follow-up would beneeded for 100 items if 100 households attempted composting, and 10,000 items if 10,000 households tried.
Therefore, it is necessary to train compost advisors who can instruct other people in the community on
composting, and establish an organization for the follow-up. In the city of Surabaya mentioned above, theEnvironment Leaders also assumed the roles of compost advisors.

21© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
The establishment of such a follow-up organization might progress smoothly in some communities, while
not in others. If establishment of the community follow-up organization seems difficult, the author
recommends establishment of a compost center of a scale fit for the situations of the region.
For example, a small-scale compost center capable of processing 30 kg of raw garbage a day can serve 600
households (if the raw garbage generated was 0.5 kg/household-day). In other words, it would be possible
to provide follow-ups for 600 question items at one location. A compost center capable of processing
5 ton/day can serve 10,000 households. A compost center of this scale can accept raw garbage from markets
and other businesses, in addition to households.
On the other hand, there are also demerits that arise as the scale of compost centers enlarges, which need to
be dealt with beforehand.
 The need for awareness enhancement on raw garbage sorting: as the scale becomes larger,
composting would be “something that is taken care of by other people rather than themselves” formost residents of the region, and they might start discharging mixed household garbage todesignated places as before. As a result, “raw garbage sorting” that affects the quality of produced
compost the most would be insufficient.
 The need for reliable daily management: troubleshooting would be more difficult as the scale
becomes larger. By conducting reliable daily management of compost, troubles may be prevented or
may be detected in an early stage and corrected in a small step.
 The need to train technical experts of composting: the scale should be determined to suit the level ofexpertise attained by the technical experts working at the site. Troubleshooting would be easier if thescale was smaller. Technical experts of composting are required not only to obtain knowledge but
also to make adjustments and corrections for applying the knowledge in a way suited to the actual
conditions at the site. Time would be needed for them to gain experiences and capabilities forresponding to these demands.
 The need to establish a raw garbage collection and transport system: raw garbage sorted at eachhousehold is to be collected and transported to the compost center. There are only a limited numberof garbage collection trucks, so the “raw garbage” and “general garbage” need to be collected on
different days of a week.
 The need to secure a land lot for compost center: securing a land lot becomes more difficult as thescale of compost center increases, and compost centers tend to be constructed at remote locations.
The place of construction should be determined, taking into consideration also the transport andother costs.
 The need to ensure market distribution and secure end users of compost products: if composting was
attempted at a household, the amount of compost produced would be small, and the compost may beconsumed at the household. On the other hand, a large amount of compost is produced at a compost

22© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
center, and the means for market distribution and end users of the compost products need to be
secured.
6.3.2

Basic conditions of compost centers(1) Points to be considered when constructing a compost center №1 Not exposed to strong wind: compost centers should be well-ventilated because compost emitssteam. However, if compost was exposed to strong wind, the temperature could go down or
rainwater could blow in.
 №2 Not exposed to rain: compost centers should always be roofed, and measures need to beprovided for preventing rain from being blown in by wind.
 №3 Rainwater should not flow in, and water should not be pooled: the floor should be raised, orwalls need to be built for preventing rainwater from flowing in.
 №4 Availability of water: water to be added or sprayed on compost would be necessary, because thetemperature of compost rises if managed properly and water evaporates. Water is also needed forwashing hands and cleaning the floor and tools.
 №5 Not exposed to direct sunlight: the temperature rises in the work site when the surrounding
temperature is high, so a rise in the temperature caused by direct sunlight should be avoided. Even
though microorganisms on the surface are damaged when the compost is exposed to the ultraviolet
rays of direct sunlight, this is not a concern if the total number of microorganisms in the compost
was considered.
 №6 Floor surface: concrete floor is highly workable, and an inclination of the floor surface and aside gutter would be convenient for washing the floor surface with water. In the case of an earthen
floor, water would penetrate into the floor easily, preventing the bottom surface of compost frombecoming too moist.
 №7 Availability of lighting facilities for work at night: this may be omitted if no work is planned
during nighttime.
 №8 Not located adjacent to houses, and keeping a distance: even though an offensive odor is not
generated in the normal composting process, a fermentation odor may be felt. A distance needs to be
kept from residences because raw garbage is accepted.
 №9 Compost centers and outbreak of flies: the temperature of compost rises to above 65℃ if
normally managed. Eggs and larvae of flies become extinct even if flies laid eggs on the compost,
and an outbreak of flies is unlikely to occur. However, if outbreak of flies took place near a compost
center, the flies are attracted to the compost center, and people might misunderstand that theoutbreak took place at the compost center.

23© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Rain

Direct sunlight

Ventilation

Fig. 5-14: Basic matters for compost center(2) Tools and machines
Examples of tools and machines used at compost centers are shown below.

 Chopping large raw garbage and Agitating compost

branches into small pieces

HatchetShovel Work safety and hygiene

Rubber gloves

Rubber boots

Hoe Measurement

Face
mask

 Water spraying

Pail

Scale

Thermometer Preparing compost as a product(moisture content adjustment)

Hose

BucketWatering pot

Sieve

Bag

Fig. 5-15 Tools used at compost centers (examples)24© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
A shredding machine for crushing raw garbage, a sieving machine for sieving the compost, and a wheel
loader for agitating the compost should stand by at compost centers of a larger scale.

Shredding machine

Trommel sieve

Wheel loader

Fig. 5-16: Machines used at compost centers (examples)
6.4

Small-scale compost center

Here, an explanation is given on a case assuming that about 30 kg of raw garbage is composted each day.
6.4.1

Step 1: Preparation[1] A small-scale compost center is established in the community.
[2] 1 m3 of seed compost is prepared as explained in “6.1.2 Preparing seed compost.”
It is desirable if a large volume of raw garbage was processed, but small-scale compost centers should
start with an amount that is hardly likely to end up in a failure so that staff members can gain
experiences. The ratio between the seed compost and the raw garbage of 1 m3 : 30 kg was obtained
based on the author’s experiences.
6.4.2

Composting procedures[1] Each household in the community should bring in raw garbage that has been sorted, drained andchopped to small pieces every day so that the total would be about 30 kg a day.
Moisture accounts for over 80% of raw garbage, and the compost could become excessively moist.
Therefore, the raw garbage should be drained, as shown in the diagram, for lowering the risk oftroubles.
[2] Measure the weight of the raw garbage and mix it into the seed compost. (Seed compost : Raw
garbage = 1 m3 : 30 kg)
The amount of raw garbage mixed may be less than 30 kg if not much raw garbage was generated.
If there is more than 30 kg of raw garbage, observe the compost conditions well, and adjust theamount of to be added. The amount of raw garbage that can be processed increases with experiences.
The most crucial points are the moisture content (40 to 60%) and the level of decomposition of raw
garbage.
[3] Input raw garbage every day for a month.
[4] The volume of seed compost should have increased to about 1.5 m3. Take out the increased amount of
about 0.5 m3 and have it matured for three weeks, for preparing it as a compost product.
However, the “increased amount of about 0.5 m3” is meant to be an example. The volume could differ
depending on the type and size of the raw garbage processed.

25© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[5] Make sure that 1 m3 of seed compost remains. After attempting composting several times, the staff ofthe compost center might feel that “gaps in the seed compost are small, and the air does not seem to bepermeating well.” In such cases, add auxiliary materials used for forming the home ground of
microorganisms when the seed compost was prepared, such as rice hull and fallen leaves.
[6] Repeat the procedures [1] to [5].

Recyclable waste

Place of collection

Chopped into
small pieces

Composting
Raw garbage
Cannot be composted
Draining

Discharged aswastes

DisposalRaw garbage storage
and collection
containers
Community compost
centerFig. 5-17: Process flowchart for household garbage

30 kg/day

30 kg/day

Put in raw garbage forone monthMatured for threeweeks
Sieving

Compostproduct

Materials remaining
on the sieve

Reused as seed compost (returned compost)

Fig. 5-18: Work process flowchart at compost center (example)

26© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
6.4.3

Examples of small-scale compost centers

When establishing a compost center, the matters indicated in “6.3.2 Basic conditions of compost centers”
should be considered. The readers are recommended to use materials and equipment that are available
locally and low-priced, and keep in mind to recycle the materials.

Photograph 5-55: Example of compost center 1

Photograph 5-56: Inside the compost center

Photograph 5-57: Example of compost center 2

Photograph 5-58: Example of compost center 3

6.4.4

Attempts at small-scale compost center (in Bhutan)

In Bhutan, training on composting and establishment and operation of compost centers are being conducted
mainly by a women’s association, under the guidance by the environment bureau of the Thimphu City
government. A system has been established in which the environment bureau purchases the produced
compost and uses it for greening in the city and for agriculture. The reason why the women’s association
enthusiastically attempts composting is found in its efforts for mutual help, in addition to promoting
hygienic treatment of unsanitary raw garbage, as well as reduction and recycling of wastes, by the entire
community. The profits gained from compost sales are pooled by the women’s association, to be used formutual assistance in the community, such as providing a scholarship to a child when the breadwinner of thefamily has deceased.

27© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[1] Preparing seed compost
Although dependent on the amount of seed compost necessary, cultivation of microorganisms using asugar solution or a saline solution may be omitted as discussed in “6.1.3 Small-scale cultivation using
household composting container,” when preparing seed compost for the small-scale compost center also.
Milk whey and marcha* are available at a low cost in Bhutan, so the step for preparing a culturingliquid was omitted.
*Marcha: a group of bacteria for preparing liquor, comprising mainly koji-mold and yeast and believed
to have originated in Nepal. It is available in traditional markets of Bhutan and is used for preparing
liquor from rice at households.

Photograph 5-59: Milk whey sold at asupermarket

Photograph 5-60: Hand-made marcha sold at
a traditional market

Photograph 5-61: A cake of
microorganisms for preparing liquor iscrushed into small pieces and put it into asugar solution

Photograph 5-62 Milk whey is added, and the
mixture is agitated well28

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-63: The mixture solution ismixed well with the base material, andmoisture content adjustment is performed

Photograph 5-64: Several days later, white
microorganisms (filamentous fungi) were found tohave proliferated on the cloth cover also[2] Raw garbage composting
Each household of the community chops the raw garbage generated at home into small pieces andbrings them to the compost center. Mainly the leading members of the women’s association put the raw
garbage into the seed compost and perform agitation work. The community plans to allocate the work inturns equally to all the households, when the raw garbage composting started progressing well.

Photograph 5-65: Raw garbage is chopped
into small pieces at households

Photograph 5-66: Raw garbage is put into
seed compost

Photograph 5-67: The seed compost and
raw garbage are agitated well

Photograph 5-68: Moisture content is checked
while agitating29© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-69: Compost being matured

6.4.5

Photograph 5-70: Finished compost in storage

Attempts at small-scale compost center (in the Philippines)

In the Philippines, compost centers are being established and operated under the instruction and training by
the environment and natural resources office of the Cebu City government, the operations being led by theenvironment staff appointed in each Barangay (community). A system has been adopted in which the entire
amount of seed compost is produced by the mother compost center and distributed to each Barangay(community) compost center. The system that has the seed compost produced at one location has stabilized
the quality of seed compost and reduced the burdens on the communities.

Fig. 5-19: Production of seed compost at the mother compost center and distribution to each community

30© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-71: Mother compost center

Photograph 5-72: Barangay (community)
compost center 1

Photograph 5-73: Barangay (community)
compost center 2

Photograph 5-74: Barangay (community)
compost center 3

Photograph 5-75: Awareness enhancement
seminar on composting

Photograph 5-76: Awareness enhancement
seminar on composting31© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-77: Compost in use
6.5

Photograph 5-78: Compost in use

Medium-scale compost center

Here, an explanation is given, assuming that about 1 ton to 5 tons of raw garbage is composted each day.
Since a large amount of raw garbage is accepted and processed each day, the staff involved is required not
only to have fully understood the composting technology but also to have attained experiences and results.
Such being the case, the risk of failure may be reduced by starting with small-scale composting and expand
the scale as the staff members gain experiences. Troubles may be dealt with easily when the amount ofcompost is small, and the staff members can accumulate experiences on troubleshooting. Such a process
also allows the staff members to gain a practical understanding of the causes of troubles, and enables themto prevent the occurrence of troubles. It is recommended that the scale of composting would be expanded
only after the staff members involved have obtained the practical know-how.
6.5.1

Step 1: Preparation (in the Philippines as an example)[1] Establishment of compost center
From the viewpoint of having staff members acquire experiences prior to expanding the scale ofcomposting, it would suffice if the compost center established has means for preventing the penetrationof rainwater. The compost center shown in the photograph has only a tent put up.
[2] Preparing seed compost
Seed compost should be prepared as described in “6.1.2 Preparing seed compost.” Large amounts ofbase materials and fermentation liquid are necessary for producing the amount of seed compost
necessary for processing a large volume of raw garbage. Since a method that gradually increases theamount of raw garbage to be processed is adopted here, the compost produced immediately after thestart will be used as seed compost. In other words, seed compost is produced for the time being, insteadof compost. If wood shavings, fallen leaves and other base materials may be obtained in addition to theraw garbage accepted, these materials should be utilized effectively for producing a large amount ofseed compost in a short period of time.

32© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-79: Producing seed compost

Photograph 5-80: The compost center is builtwith bamboo frame and tent put up as a roof

Photograph 5-81: The scale is expanded as
staff members attain experiences

Photograph 5-82: Shifting to another place for
expanding the scale

6.5.2

Composting procedures (in the Philippines as an example)[1] Sorting and crushing of raw garbage
As already discussed, foreign matters mixed into raw garbage cause the quality of produced compost to
decline. In the case of a mixed waste, only raw garbage should be picked up and used as the source
material of compost. If the amount of raw garbage accepted increases, it would be necessary to conductcomposting efficiently. One of the methods to achieve this is by crushing raw garbage into small pieces.
Food wastes from food factories make a good raw material, because no foreign matter is mixed in them.

33© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-83: Only raw garbage ispicked up from mixed waste

Photograph 5-84: Large-sized raw garbage iscrushed into small pieces[2] Inputting the raw garbage
A lane-type form of raw garbage inputting is adopted here. The processes described below are meant as
an example for reference.
 Form a recess at the center of seed compost and put in raw garbage, and cover with the seed compost
so that the raw garbage is no longer visible. (The raw garbage is like sweet bean paste filling in asweet bun, or a peanut covered in chocolate) Leave the seed compost and raw garbage for a day, without agitating right away. The seed compost
absorbs the water seeping out from the raw garbage. No odor is generated, because the raw garbage
has been covered by the seed compost.
 Then, agitate sufficiently while moving the seed compost. Manual agitation is a cumbersome labor,
but keep trying while imagining that the air is mixed into the seed compost.
 The amount of raw garbage to be input changes depending on the moisture content of the raw
garbage and the seed compost. Make a judgment to suit the situations of moisture content, rather
than inputting a predetermined amount. The moisture content suited to composting is 40 to 60%.
 In the case of continuous input-type composting, use the ratio “30 kg (of raw garbage) per m3 ofseed compost a day” as a reference.
 In the case of batch-type composting, use the ratio “1 ton of raw garbage per 1 ton of seed
compost” as a reference.
 Circumstances under which the amount of raw garbage input may be increased (examples): When the atmosphere is dry in a dry season
 When the temperature of seed compost is high, and a large amount of water is evaporating When the raw garbage is of a type that is decomposed promptly. (The raw garbage is in small
pieces, carbohydrates, etc.)
 Circumstances under which the amount of raw garbage input should be restricted:
34© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
 When the atmosphere is humid during a rain season
 When the amount of moisture evaporating from the seed compost is small, and the moisture
content is close to the upper limit of 60%
 When the raw garbage is being decomposed slowly

Photograph 5-85: A recess is formed at thecenter of seed compost

Photograph 5-86: Raw garbage is put in therecessPhotograph 5-87: Food waste from a foodfactory is also a good-quality raw material(sludge from a corn processing factory)

Photograph 5-88: Agitation is conducted
while moving the seed compost[3] Expansion of compost center and market distribution
The compost center started with 10 m3 of seed compost, which was expanded to 50 m3 at anotherlocation, and to 250 m3 in the end. The compost center is an extremely simple type that was built
manually, using steel pipes and bamboos for columns and stretching a tent as the roof. It is a good
example that kept the initial investment and running costs small, while creating job opportunities.
In order to expand a compost center, it is crucial to develop a market for distributing the produced
compost. In this example, the compost product is being sold to a fertilizer company. Needless to say,measures have been incorporated so that the quality standards demanded by the fertilizer company
would be met. The quality standards involve, for example, adjustment of types of raw garbage used as
the raw material, the composting period, sieving, etc.
35

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-89: The scale was expanded
gradually to 250 m3 of seed compost, while
the staff members accumulated experiences
6.5.3

Photograph 5-90: High-quality compost is
being produced and soldAttempts at medium-scale compost center (in Bolivia as an example)

In Bolivia, managers of compost centers have led activities to promote composting, under guidance by thewaste treatment department of the environment bureau of the Tarija City government. The emphasis wasplaced on sorting of raw garbage prior to collection. Five model environment districts were established first,
awareness enhancement activities were conducted with the residents, and about 1 ton of sorted raw garbage
was collected per week. Four months later, additional model environment districts were set up, and now
there are ten such districts. An elementary school of the district was appointed the school for promoting
sorting of wastes, and the school children instructed residents in the neighborhood on waste sorting. The
residents in the neighborhood brought sorted raw garbage in a pail to the school, and the environment
bureau staff collected and transported them. As a result, the amount of sorted raw garbage collected
increased to 8 ton/week. The produced compost was distributed among the residents as a gift in the firstyear, as a part of the awareness enhancement activities for promoting sorting of raw garbage. Starting in thesecond year, the raw garbage collection bases opened, where the produced compost is being sold. The
ministry in charge of land and rural village development is also planning to purchase the compost.
The compost center is also being utilized as a place of environment education at schools.
[1] Establishment of the compost centerRaw garbage is collected three times a week, on
Monday, Wednesday and Friday, and a total of 8
tons of raw garbage is carried to the compost center
each week. The size of the compost center is 60 m inwidth by 13 m in depth.
[2] Preparing seed compost
Seed compost is being prepared as described in

Photograph 5-91: Compost center“6.1.2 Preparing seed compost.” Fallen leaves andwheat bran are used in Tarija City, because rice hull and rice bran are difficult to obtain. Fermented food36

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
products are also difficult to obtain, so a large amount of dry yeast is mainly used as it is available mostof the time at a low cost. At the start, ten heaps of 1.5 m3 seed compost were prepared.
[3] Actual steps of composting
Sorted and collected raw garbage is carried into the compost center on Monday, Wednesday and Friday(total of 8 ton/week), and staff members roughly chop the raw garbage. The mixing ratio between the
raw garbage and the seed compost should basically be “Seed compost : Raw garbage = 7 : 3.” The raw
garbage is divided into equal parts and is mixed into the ten heaps of seed compost. However, no raw
garbage is mixed into seed compost in bad conditions, such as the one with excessive moisture content
or the one in which decomposition of raw garbage has delayed. The basic policy is to leave such heap atrest. Moisture content adjustment and agitation are performed for all the heaps every day, regardless ofwhether raw garbage has been input. After putting in raw garbage for three months, the compost is
matured.

Raw garbage is input after judging
the conditions of seed compost

Fig. 5-20: Composting procedures

There were ten heaps of seed compost at the start. As time went by, maturing started with some of the heaps,
to which raw garbage was no longer input. A new heap of seed compost was formed in line with theprogress made. In the end, ten heaps of seed compost into which raw garbage may be input, and five heapsof seed compost in the maturity stage, came to be managed. The period of maturing is one month.

Ten heaps of seed compost

Five heaps in the maturing stage

Raw garbage is input after judging theconditions of seed compost

Raw garbage is no longer input

Fig. 5-21: Composting procedures37© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-92: Raw garbage is being
chopped with a hatchet

Photograph 5-93: Raw garbage is put into theseed compost

Photograph 5-94: Satisfactory fermentationis going on and a lot of steam is rising

Photograph 5-95: Checking the conditions
every dayPhotograph 5-96: The seed compost turns
to blackish color from brownish color as
time goes by

Photograph 5-97: The compost center is being
also used as a place of environment education

38© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
6.5.4

Attempts at medium-scale compost center (in Ecuador as an example)

In Ecuador, a compost center had been constructed and instructions had been given on composting
technology by a country other than Japan, as a part of the international cooperation efforts. However,expected results had not been obtained, and the compost center was not being used. Then, Takakura
Composting Method was introduced to the country through the volunteer programs of the Japan
International Cooperation Agency.
Composting of business wastes from markets and other places is being attempted in Ecuador, under theguidance by the environment bureau of the Macas City government. Composting is basically conducted on
sorted raw garbage, and exclusive trucks for collecting and transporting raw garbage are in operation.
Plastic and other foreign matters are mixed in the raw garbage carried into the compost center, and theseneed to be removed. Since sorted raw garbage is being collected in Macas City, removal of foreign matters
is feasible. If composting was attempted on mixed wastes that are not sorted, low-quality compost would be
produced as explained in the case in the Philippines, unless raw garbage is picked out from the mixed
waste.
[1] Establishment of compost center
The existing compost center is being used. As shown in the photograph, side gutters for draining
wastewater are provided on the assumption that wastewater seeps out from the compost. No wastewater
has generated since the introduction of Takakura Composting Method, and side gutters are now ahindrance to the work. (People trip over the gutters during work, side gutters hinder the passage ofwheelbarrows, etc.)[2] Preparing seed compost
Since a composting center was already in operation in this country, the compost products in stock are
mixed with fallen leaves to be used as the seed compost. Finished compost product may be used as
returned compost. Macas City is located at an altitude around 1,000 m in the Amazon region, whereplenty of trees grow. Existing resources in the area are being utilized effectively.
[3] Actual composting steps
Awareness enhancement activities were conducted on sorting of raw garbage, at markets wherecollection of sorted raw garbage was relatively easy. The businesses have cooperated with the sorting of
raw garbage prior to collection.
Raw garbage carried into the compost center contains only a small amount of foreign matters, so themixing ratio of foreign matters in the raw garbage used as the raw material of composting may belowered, just by picking out foreign matters from the raw garbage.

39© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-98: Sorted raw garbage isbeing collected

Photograph 5-99: Plastic and other foreign
matters are picked out

Photograph 5-100: Foreign matters thathave been picked out

Photograph 5-101: High-quality raw materials
for composting

Since the amount of raw garbage to be processed is large, the raw garbage is crushed into small pieces
using a shredding machine. If the raw garbage carried in was composted as is without crushing, theamount of time needed until completion would be longer and the yield of finished compost productwould decline.

Photograph 5-102: Raw garbage is crushed
using a shredding machine

Photograph 5-103: Raw garbage crushed tosmall pieces40© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
Lumber processing is a leading industry in Macas City, and a large amount of sawdust used to bedisposed of as wastes. By using the sawdust as a material for absorbing moisture, the amount of raw
garbage processed may be increased and the amount of seed compost that needs to be mixed may besuppressed. Furthermore, sawdust may also be recycled through composting.

Photograph 5-104: Sawdust is laid as amoisture absorbing material

Photograph 5-105: Seed compost (returned
compost) is laid

Photograph 5-106: Raw garbage that has
been crushed to small pieces is carried in

Photograph 5-107: Raw garbage is placed onseed compost and is sandwiched by placing
another layer of seed compost

By covering raw garbage with seed compost and sawdust, odors may be suppressed and flies are kept away.

Photograph 5-108: Covering with anotherlayer of seed compost

Photograph 5-109: The compost is covered
further with sawdust

41© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
Starting on the next day, the compost is agitated for having the water seeping out from the raw garbage
absorbed. Agitation is being done once every three days. The composting period may be curtailed if
agitated once every day or once every two days, but the number of people working at the compost
center is small, and consideration has been given on their workloads.
Composting is finished after elapse of 45 days. The composting period relates not only to the frequency
of agitation, as mentioned above, but also to the amount of seed compost mixed. Here, the amount of
mixed seed compost has been reduced, and sawdust is being used for absorbing the moisture so that thelargest portion of the finished compost may be shipped as compost products. A long composting period
is needed, especially when sawdust is used, and 45 days is believed to be appropriate.

Photograph 5-110: Starting on the next day,the compost is agitated once every threedays

Photograph 5-111: The compost is sieved
after elapse of 45 days

The portion of compost that did not pass through the sieve is used as returned compost. Here, foreign
matters also remain on the sieve. If the amount of foreign matters is judged to be large, the compost on
the sieve is discarded along with foreign matters.

Photograph 5-112: Portion of the compost remaining on the sieve is used as returned compost
If there is a large amount of foreign matters, the entire portion remaining on the sieve is discarded42© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
The portion of compost that passed through the sieve is almost free of mixed foreign matters and makes ahigh-quality compost product. The efforts given for sorting and collecting raw garbage and picking out raw
garbage from mixed wastes are reflected in the improved quality of compost.

Photograph 5-113: The portion that passed through the sieve makes a high-quality compost product
The produced compost is packaged and shipped. In Macas City, the compost is being used in green spacesof parks, for making culture soil for seedlings in pots and as a fertilizer for trees and plants.

Photograph 5-114: Compost is measured,
packaged and shipped

Photograph 5-115: Culture soil used in flower
beds in parks is being produced

Photograph 5-116: Culture soil used inflower beds in parks is being produced

Photograph 5-117: Compost is used withseedlings in pots

43

© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-118: Flowers in pots that use
compost are planted in the flower bed

6.6

Photograph 5-119: Compost is applied as afertilizer on the flower bed

Large-scale compost center

Here, an explanation is given assuming that 5 tons or more of raw garbage is accepted each day, andcomposting is done using a wheel loader, a compost plant and other machines.
Since a large amount of raw garbage is accepted and processed every day, the staff working at the compost
center needs not only to possess knowledge on composting technologies but also to fully understand how to
operate the machines, and furthermore should have acquired experiences and attained results in composting.
For this reason, a small-scale composting should be started for the technical staff members so that they canacquire experiences and attain results in composting, as soon as a plan to build a large-scale compost center
is finalized. Misunderstanding frequently occurs that as soon as a compost plant is constructed, compost
would be finished just by turning on a switch, or machines work automatically to produce compost. Also,
the technical staff should fully learn how to operate the machines, including the principles and theories,
from the plant manufacturer prior to the handover of the plant. By keeping these two points fully in mind,
the risk of failure could be reduced.
Since several dozen tons and hundred tons of raw garbage is accepted daily, the compost plant could neverstop operation. It would be necessary to conduct daily operation management for preventing and foreseeing
troubles, and implement countermeasures promptly when a trouble occurs. Please keep in mind that these
are the essential requirements when a large-scale composting is attempted.
6.6.1

Step 1: Preparation[1] Establishment of compost centeri

Expanding medium-scale compost center
When the scale of a medium-scale compost center is expanded by enlarging the seed compost,
manual agitation would be difficult, and a wheel loader needs to be introduced for efficientagitation. Fermentation tanks partitioned by a concrete wall are installed in some cases forfacilitating fermentation management, or the composting steps might be conducted in an open
space in other cases. However, it is essential to prevent intrusion by rainwater in all cases.
44© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology
ii Compost plant
There are various types of compost plants. An optimum plant should be introduced, after
consulting with the plant manufacturer.

Photograph 5-120: Medium-scale compost
center being expanded

Photograph 5-121: Compost plant (example)[2] Preparing seed compost
Seed compost should be prepared as described in “6.1.2 Preparing seed compost.” In order to process alarge amount of raw garbage, large amounts of base materials and fermentation liquid are also necessary
for producing seed compost of an appropriate amount. The method that gradually increases theprocessed amount of raw garbage is adopted, and the compost produced in the initial stage will be usedas seed compost. In other words, compost is not produced in the initial stage, but instead, seed compost
is produced. If wood shavings, fallen leaves and other base materials may be obtained at the same time
accepting the raw garbage, these materials should be used effectively so that a large amount of seed
compost may be produced in a short period of time. If existing high-quality compost is available, it
should also be utilized.

6.6.2

Attempts at large-scale compost center (in Vietnam as an example)

In Vietnam, the waste management public corporation under management of the construction bureau of theHai Phong City government is responsible for collection, transport and disposal of wastes. The amount of
raw garbage generated is large, and recycling and volume reduction of wastes by composting was judged tobe effective. Thus, a compost plant (with the waste acceptance capacity of 200 ton/day) had been
constructed utilizing an ODA scheme. However, technology transfer by the overseas plant manufacturer
had not been sufficient, and the capacity of the plant had not been utilized effectively. Another possible
reason for the ineffective usage is that instructions on the overseas technology had been given only in a
one-sided manner and optimization to suit the local situations had not been attempted.
Thus, local optimization of the compost technology was attempted this time, in a way suited to the existing
compost plant.
45© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[1] Acquiring the compost technology
The waste acceptance capacity of the existing compost plant is 200 ton/day, and several dozen tons of
raw garbage would be processed even during a trial operation based on the new technology introduced.
Therefore, the staff members working at the plant need to fully understand the basic theories ofcomposting.
The staff members learned the basic theories of composting that have been discussed above, throughlectures. Then, their understanding on the basic theories was promoted through pilot tests for confirming
the consistency between the theories and the actual phenomena, one by one. The staff members started
with the preparation of seed compost, then actually added raw garbage for confirming the progress ofcomposting.

Photograph 5-122: Understanding on thetheories is deepened through lectures anddiscussions

Photograph 5-123: Fermentation liquid isprepared for pilot tests

Photograph 5-124: Microorganisms forfermentation are collected

Photograph 5-125: Explanations are given on
ray fungi and basidiomycetes46© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-126: Rice hull and rice bran
are mixed for preparing seed compost

Photograph 5-127: Microorganisms forfermentation collected from the forest are
mixed into fermentation liquid

Photograph 5-128: Seed compost is being
prepared

Photograph 5-129: Checking on the moisture
content

Photograph 5-130: Staff members
reviewing the seed compost preparation
steps

Photograph 5-131: Staff members discussing
on the seed compost preparation47© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology[2] Preparing seed compost for trial operation at the existing compost plant
Since rice is the staple food for the people of Vietnam, seed compost was prepared using mainly ricehull and rice bran. The scale of seed compost preparation was expanded based on the outcomes of thepilot test.

Photograph 5-132: Large amounts offermentation liquid is prepared

Photograph 5-133: Quality of fermentation
liquid is checked based on the odor

Photograph 5-134: Rice hull is mixed withrice bran

Photograph 5-135: Microorganisms forfermentation collected from a forest are
mixed with fermentation liquid

Photograph 5-136: Moisture content isadjusted by spraying fermentation liquid
and water

Photograph 5-137: Seed compost is being
mixed

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© 2019 Koji TakakuraChapter 6 From the basic theories to practical application of composting technology

Photograph 5-138: The temperature of theseed compost is checked

Photograph 5-139: The completed seed
compost[3] Actual composting steps
A large amount of cost would be needed for producing a large amount of seed compost, for purchasing
and transporting a large amount of rice hull, rice bran and other materials for preparing fermentation
liquid, as well as for production work. Furthermore, the existing plant adopted a system that accepts
mixed wastes and sorts raw garbage from them in the plant. However, sorting was not performed
thoroughly, and the quality of compost products tended to be low. Thus, it was decided to accept only
sorted raw garbage at the compost plant.
The amount of raw garbage accepted at the compost plant increases as the amount of sorted raw garbage
collected in the city increases. As such, the entire amount of the produced compost is returned as seed
compost in the initial stage, instead of shipping it as compost products. This way, the staff members may
acquire experiences and achieve results in compost plant operations, at the same time producing seed
compost from raw garbage.

49© 2019 Koji TakakuraChapter 6 From the Basic Theories to Practical Application of Composting Technology

Sorted organic wastes
are collected andcarried inLarge-sized organic waste fit for composting

Materials
remaining on thesieve (10cm)Seed compost
is input

Organic waste is input
using a wheel loader

Matters not fit for composting
are disposed by landfill

Vibration hopper
Foreign matters are removed andorganic waste is homogenized
Magnetic
sorting
Foreign matters
are removed

Trommel sieve

Foreign matters collecting cart

Gear-typecrusher

Iron collecting
cartForeign matterscollecting cart

Mixture of seed compost and organic waste

Ventilation fan
Ventilation fan

Maturing yard
Period of maturation:
30 days

Fermentation (composting)period: 20 days

Vibration hopper

Materials remaining
on the sieve

Trommel sieve

Reused as returned seed compost
Or, matters not fit for composting aredisposed of by landfill

Shipped and sold as compost product
Reused as returned seed compost

50

Fig. 5-22: Process flowchart of operations at
Hai Phong City Compost Center© 2019 Koji TakakuraChapter 6 From the Basic Theories to Practical Application of Composting Technology

Photograph 5-140: Sorted raw garbage iscollected

Photograph 5-141: Foreign matters are
removedPhotograph 5-142: Foreign matters are
removed using Trommel sieve

Photograph 5-143: Foreign matters are
removedPhotograph 4-144: Seed compost is
scatteredPhotograph 5-145: Seed compost is scattered51© 2019 Koji TakakuraChapter 6 From the Basic Theories to Practical Application of Composting Technology

Photograph 5-146: Raw garbage and seed
compostPhotograph 5-147: Raw garbage is mixed
with seed compost

Photograph 5-148: The mixture istransferred to fermentation tank

Photograph 5-149: Fermentation of the
mixture starts

Photograph 5-150: Transferred to anothertank and agitated, for ensuring thoroughagitation

Photograph 6-151: Steam indicating the
progress of satisfactory fermentation

52© 2019 Koji TakakuraChapter 6 From the Basic Theories to Practical Application of Composting Technology

Photograph 5-152: Each tank is equippedwith an aeration facility

Photograph 5-153: Maturing yard for compost

Photograph 5-154: Fully matured compost
is sieved

Photograph 5-155: Finished compost productPhotograph 5-156: Compost being used

Photograph 5-157: Compost being used

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© 2019 Koji TakakuraChapter 6 From the Basic Theories to Practical Application of Composting Technology
References: Koji Takakura: Kaigai Gijutu Kyoryoku wo Tsuujita Takakura-shiki Konposuto no Gijutsu Iten ni
Kansuru Kenkyu (A Study on Technical Transfer for Takakura Composting Method throughOverseas Technological Cooperation), doctoral thesis, Graduate School of Life Science and Systems
Engineering, Kyushu Institute of Technology, May 2016
 Institute for Global Environmental Strategies: Nama Gomi Konposuto-tte Sugoi! (Raw Garbage
Composting is Great!), 2013
 Institute for Global Environmental Strategies: Composting for Waste Reduction; INFORMATION
KIT, 201054© 2019 Koji Takakura