Urban India produces up to 42.0 million tons of municipal solid waste annually, i.e., 1.15 lakh metric tons per day(TPD), In which 30-55% is of biodegradable (organic) matter, 40% to 55% inert matter, and 5% to 15% recyclables.

With the increasing trend of municipal solid waste, the proportion of organic waste is also increasing. It makes up more than half of the total waste, i.e., approx 55%. 

Waste trend in india
Waste trend in india. Source:- Indian Council for Research on International Economics Relations

Compostable waste is in very high proportion. Waste can transform into valuable products such as methane gas, compost, biofuels, char, etc. These profitable components can be obtained by various methods, like:-

Compositable and recyclable waste
Compositable and recyclable waste ratio in India. Source:- CPCB

1.Waste to energy

(a) Pyrolysis

(b) Plasma pyrolysis

(c) Incineration 

(d) Biomethanation

(e) Pelletization/ Refuse derived fuel (RDF)

2. Waste to compost

(a)Aerobic composting

(b) Anaerobic composting

(c) Vermicomposting

In this blog, I will tell you about a well-known composting method, i.e., the Indore method. 

First, let’s start with how it is named and its Introduction.

What is the Indian-Indore Method of composting?

 Wad and Howard developed this method in 1931 in Indore, Madhya Pradesh, India. Therefore, it is called the Indian Indore method. 

Refuse and night soil is immediately treated by this method. A trench of 2 feet deep and 15 feet broad is made. Building metallic roads at the side and in between the trenches is advisable.

Raw Materials

The raw materials used in this process can be any decomposable organic waste, such as paper, kitchen waste, human feces, agricultural waste, etc. Some of the residues depend upon their availability I’m mentioning here.

Availability of residue Examples
Residue in low quantities Waste paper, packing materials, shavings, sawdust, worn out gunny bags, old canvas, worn out uniforms, old leather belting, etc.
Residue in moderate quantities Mixed dried grass, gram stalks, wheat straw, uneaten and decayed silage, millet stalks damaged by rain, residues of the safflower crop, ground-nut husks, ground-nut stalks and leaves damaged by rain, sugar-cane and millet stumps, kitchen refuse, etc.
Residue in large quantities Cotton stalks, sann hemp – either as green plants reaped before the flowering stage or as dried stems of the crop kept for seed, pigeon-pea stalks, sugar-cane trash, weeds, fallen leaves, etc.

Layering of the trenches

Layering of trenches

First charge is done by leaving a vacant space of 4 feet to a side. Refuse of carts is dumped into these trenches and spread by drag rakes. Making a heap of three to four inches. After dumping, a charged inoculum of at least 2 weeks is then mixed to fasten up the process. Night soil is then tipped as the upper layer. More refuse is added over the night soil. Then the lower layer, inoculum and upper refuse is mixed by drag rakes in small lots until the breadth of the opposite side of the trench is covered. 

Day by day more refuse is added until the trench is covered. Top layer should be refused only without being mixed into the lower layers. So, as to act as a barrier layer, uniform moisture and heat in the whole mass of the mixture, and to prevent the breeding of fly larvae on top. 

Night soil- Refuse Proportion  

There is no fixed proportion of these. If the night soil is very liquidy, amount of night soil is high, refuse should be mixed until it is properly mixed either by upper margin from the surrounding. After charging and later turns heaps with the flat tops and vertical sides are made. Otherwise difficulties like preventing waterlogging in a wet season and keeping uniform moisture during dry weather will arise.

Turns

First turn :- After 2 days of charging i.e. 4 days from start. Four-pronged garden digging fork is found suitable for turning.

Water should be added with a hose or by hand after turning for soaking. This helps in preventing extra addition of water, water logging and o seeping. 

Second turn:- After 8 days a second turn is performed by forking over to the other side of the trench. Add water if necessary. 

Third turn:- 8-15 days after second turn. It depends upon the decomposition stage. Advance degree crumble of the material shows the finishing of the stage. Mass is then forked out from the trench and heaped on the adjacent storage ground. The length of the heap should up to four feet. 

Turning in Indian Indore method of composting

Process Duration 

3-8 weeks is the duration for manure preparation after charging. Duration of the process depends upon:-

  • The night soil-refuse ratio, 
  • The correct moisture control, 
  • Air throughout, and 
  • The season.

Temperature and pH

A rapid change in temperature and pH is observed throughout the process. After the first turn temperature rises rapidly, usually above 65 degree celsius, but never below 45 degree celsius. Studies show aerobic thermophilic bacteria thrive best between 43 degrees and 63 degrees C.; the fungi between 40 degrees and 55 degrees C. It reduces to normal room temperature by the end of the process. Because at the ending stage it turns vegetable scraps to humus. 

Studies show that cellulose decomposing bacteria multiply most strongly at pH 7.0-8.0. But after charging, due to speedy decomposition the mixture can be slightly acidic at the starting stage. 

Economics Related to the Process

Economic factors of indore composting method infographic
Economic factors of indore composting method

This process enables us to overcome profitability by the formerly disposal ground management. Even if the manure is sold at a low price it’s more profitable than refuse and waste. It’s a profitable waste to produce byproduct examples. 

Humus as finish product-min

The main cost related to this process is:-

  • Labour cost
  • Water supply cost
  • Land (if on rent)
  • Cost of collection 
  • Cost of transport
  • Packing cost of the manure

This process is very economical, helps in waste minimization, easy, simple and all the raw materials in need are very inexpensive. This process does not need any skilled workers or machinery.    

advantages of indore composting method infographic
Advantages of indore composting method

Advantages of Indian-Indore Method of Composting 

There are many advantages of this method, some of them are mentioned below:-

  • Capital expenditure is low.
  • Has a low operating cost.
  • Building simple trenches doesn’t need any engineering knowledge.
  • Idle dumping ground area produces economy.
  • Prevent breeding of flies.
  • Prevent generation of bad odors.
  • Exceptional hygiene of dumping grounds.
  • Doesn’t need any professional/skilled supervision.
  • Processes can be done in any season and on open ground.
  • Production of manure needs very less time.
  • Resultant manure is produced in large quantities.
  • Equally applicable for large and small quantities.
  • Surplus income becomes available for other sanitary measures for improving public health.  
  • It’s an eco-friendly process. 
  • Manure is very effective to the crops.  

Advantages of Indian Indore method of Composting

Conclusion    

The Indian- Indore method is one of the most beneficial methods for waste management.By having low capital and operational cost it produces good quality product. Manure is sold in the market at a good price. The resultant black-brown manure is rich in phosphorus, nitrogen and has a low C:N ratio. These are the qualities of good manure. It’s fine powder texture enables the Indore compost to be rapidly and easily incorporated, and to exert its maximum effect on the internal surface of the soil.

If you have any query related to the Indian Indore method of composting, you can reach out to us. Share your thoughts in the comment section down below. For more informational blogs subscribe with us. It matters a lot to us.  

andleep zahra
Author

She is a biotechnologist and received her master degree in biotechnology from V.B.S. Purvanchal University. Being a biotechnologist she loves to do research and write articles on the same. She’s best known for writing articles and blogs on environmental issues. Through her writings she likes to provide more information on environmental conservation and provide knowledge on how to address the issue, mainly focused on waste management. She looks for ways to get involved and also attended several conferences, workshops and webinars. “Increasing waste around the globe that is affecting our ecosystem and reducing our biodiversity is the most critical issue we humans often overlook and it will be the greatest challenge our younger generation will ever face,” she says.

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