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Jul 28, 2011

Composting in India

**References in this post need to be updated**

Composting is the biological decomposition of the biodegradable organic fraction of MSW under controlled conditions to a state sufficiently stable for nuisance-free storage and handling and for safe use in land applications [44]. 

Composting is the most widely employed MSWM technique in India, with above 56 composting plants in more than 43 cities [36] [37] [38] [39] [40] [2]; most of these composting facilities handle between 100 – 1000 TPD of MSW [will attach an Appendix]. Composting is successful because it is a low cost and low infrastructure set-up and also produces compost, which is a marketable byproduct. The capital investment for building a composting plant is $ 4,476 per ton (INR 200,000) of waste processed [4] and the compost is being sold at $ 45 – 49 per ton (INR 2,000 – 2,200) [28]. Availability of government aid and rising entrepreneurial interest resulted in an upsurge in the number of composting facilities nationwide. Composting of MSW is undertaken by either of the two methods, a) Windrow composting or b) Vermicomposting. During the trip, I observed that vermicomposting was employed by towns or small cities generating MSW < 100 TPD, whereas larger cities employed mechanical windrow composting, which minimizes manual handling of wastes.

Fig 1: Rejects from the composting plant at Nasik (/Nashik)

Small scale Biomethanation (Biogas) in India

**References in this post need to be updated**

Anaerobic digestion (AD) of kitchen waste to produce biogas and liquid slurry on a small scale has been very successful in India, especially South India, where the region’s temperate weather conditions favor the process yearlong.  Many households have such biogas units installed. Total number of units installed in cities is unknown as there are too many companies offering them and the units being installed in both urban and rural areas, while the numbers are not necessarily recorded. In order to have a closer look at this technology, I identified a private company called Biotech with its office in Thiruvananthapuram, Kerala as a case study for small scale biogas. This company alone installed twenty thousand (20,000) units of small scale biogas in Thiruvanathapuram and Kochi, combined. Biotech can be considered a more successful company in this area, which might help gauging number of units installed by others. These units divert about 40 tons of waste from landfills, which is 3.5% of the organic waste generated in both cities together. It also implies avoidance of 2.6% of collection and transportation costs and resulting GHG emissions.

A small scale (2 kg per day) Biogas unit at Biotech's office in Thiruvananthapuram


CH4 Methane
Carbon Dioxide
Government of India
INR Indian Rupee
JnNURM Jawaharlal Nehru National Urban Renewal Mission
LFG Landfill Gas
Mechanical Biological Treatment
MSW Municipal Solid Waste
NEERI National Environmental Engineering Research Institute
Refuse Derived Fuel
SLF Sanitary Landfill
SWM Solid Waste Management
USD United States Dollar
WPs Waste Pickers
WTE Waste-to-Energy
WTERT Waste-to-Energy Research and Technology Council