Unfit to burn

  • 14/03/2007

Indian garbage

It is common knowledge that India's informal recycling system, run by hundreds of thousands of unrecognised and exploited ragpickers, is highly efficient. This is why the calorific value of garbage is so low. "Considering the characteristics of typical Indian waste (about 50-60 per cent compostables, 30-40 per cent inerts) composting is still the first choice, as it is well demonstrated and can be applied at household level to very large scale (say 1000 t/day). However, it is to be integrated with a marketing network for the compost, diversion of inerts at the collection stage itself, and provision for disposal of residuals by landfilling,' says Kurian Joseph, assistant professor of environmental engineering at the Centre for Environmental Studies, Anna University, Chennai.

The Union ministry of environment and forests brought out a white paper on pollution in Delhi.Based on a critical analysis of biological treatment, it recommends composting over incineration: "The experiences of the incineration plant at Timarpur, Delhi, support the fact that thermal treatment of municipal solid waste is not feasible in situations where the waste has a low calorific value.' The committee appointed in 1998 by the Supreme court says: "Calorific value of Indian waste is 800-1,000 kilo calories, which is very low. It is not suitable for incineration.' (People who understand garbage incinerators say waste should have a minimum calorific value of 2,000 kcal for making wte work.) It does not recommend incineration of garbage because of the high ash and dust contents of Indian wastes. It also says incineration is not environmentally friendly, has high capital costs (especially for emission control), and has high operation and maintenance costs.

Nema says the wte concept is fundamentally unsuitable in a warm country like India and, therefore, economically unviable: "If 100 units is the input in a direct combustion incinerator, only about 25 units will come out as energy.' Of the remaining 75 per cent, about 34 per cent is lost as heat. "In colder climes like in Europe, this 34 per cent heat is trapped and channelled into home heating systems, providing additional revenue generation that is critical for the financial viability of the incineration system,' he explains.

A report by The Energy and Resources Institute of Delhi says the existing wte plants "have not proven themselves techno-economically'. Comments Krishna: "It is surprising that the report still advocates some form of government subsidy to make wte facilities more viable in India.'

What's the imperative?
"Recycling and re-use, in almost all cases, is likely to be more efficient than direct combustion... no technological interventions [should] become an obstacle in promoting segregation, recycling and other such more difficult but desirable processes,' says the wte expert committee report.

The differing members' report emphasises that wte projects should be taken up for research and development only. It also feels the dire need to improve stakeholder involvement in the collection and transport of garbage in line with the 74th amendment to the Constitution of India.

In March 2003, the moud appointed an inter-ministerial task force on using city compost for plant nutrient management, in accordance with court orders. Its 2005 report has been accepted by the ministry and, in September 2006, the court also ordered its implementation with immediate effect. What did it recommend? Setting up 1,000 composting plants based on garbage in cities across the country.

"The Planning Commission recommended some kind of subsidy to organic manure produced in compost plants, just as there is a subsidy for fertilisers,' says Khanna, who was on the task force. "Every year about Rs 14,000-crore subsidy is granted for fertiliser sale. It would be highly desirable to allocate 5 per cent of that for the sale of compost... Since funds available with the ministry of agriculture for setting up of the compost plants are very meagre, adequate funds to the extent of Rs 700 crore should be provided by the ministry of finance to set up about 1,000 compost plants in different cities,' says the report. It asks municipalities to segregate bio-degradables and supply them free to compost plants.

Nema says that none of the technologies including compost and biomethanation would work in isolation: "Waste deserves a decent burial. We cannot treat it as a money-making exercise. We can use any option for biological stabilisation or treatment, but ultimately we have to go in for scientific landfilling. Unlike any other mode of disposal, landfill is very forgiving. It can tolerate any kinds of fluctuations in both quality and quantity of waste,' he concludes.

"We need a dedicated institutional mechanism. Waste management is mostly under municipal health services, headed by medical doctors that may not be well versed with waste management, and have several other priorities,' says Joseph. "Many private parties have started compost plants, and many more are willing to invest in cleaning cities and revitalising our depleted soils with organic manure,' says Patel.

With inputs from Suchitra M in Kochi and Zehru Nissa Shah)

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