Space Tech A Solution: Towards safe urban waste disposal

Mounds of garbage lying unattended in street junctions, is a common sight in many urban areas of the country. Clearly and apparently, such a mass of garbage is both an eye sore and health a hazard. Though over the last one decade serious attempts have been made to devise and apply innovative technologies for the safe disposal of the urban waste, they have failed to yield desired results on account of a variety of factors.

 

However, in a heart warming development advances in space technology are being exploited to help solve the urban challenge of waste management. The expertise developed at the Regional Remote Sensing Service Centre (RRSSC) of the Indian Space Research Organisation (ISRO) in the area of satellite-based remote sensing is being used to put in place an appropriate system for the “safe urban waste management” by utilizing the high resolution data made available by India’s advanced remote sensing satellites like Cartosat-1 and Resorucsat-1, a three dimensional model has been devised to locate appropriate garbage dumping sites so that the wastes do not flow into the nearby low lying water bodies. As pointed out by ISRO sources, by combining satellite remote sensing data with GIS (Geographic Information System), it is possible to facilitate smoother site selection for solid waste disposal. The Jodhpur-based RRSSC has developed a customized GIS package named “Package for Optimum Routing Interactive Resource Allocation and Facility Management” to help urban bodies find out suitable garbage dumping sites.

 

“ISRO is working with several other departments for implementing the solid waste management system. The model which ISRO has developed can be applied to cities like Bangalore in managing solid urban waste. The booming metro of Bangalore, the fifth largest urban conglomerate in India, spends as much as Rs 2000 million a year on the disposal of about 3,000 tonnes of organic waste materials. On the other hand, Mumbai, the commercial capital of India which generates the largest volume of urban waste in India spends a whopping Rs 12,000 million for the safe disposal of its huge urban waste.

 

It has been computed that the per capita solid waste generated in India varies from 200 gms for small town to 500 gms for metropolitan cities. In contrast, the urban waste generated in the United States of America (USA) per day per person is around 2 kg.

 

Interestingly, the Ranchi urban agglomerate of Jharkand has adopted ISRO model for locating suitable land-fill sites for its urban waste. As it is, the Municipal Solid Waste Rules 2000 clearly stipulates that the landfills are to be developed by the local bodies without causing adverse environmental impact or health hazard to the community. For the open burning of urban waste is known to release many harmful gases and hazardous substances into the atmosphere.

 

Against this backdrop, the vermin composting technology developed by the Indian Institute of Technology (IIT) at Mumbai can be profitably utilized to treat urban wastes in an environmentally friendly manner. For the introduction of vermin composting technology results in the conversion of the urban wastes into useful compost. Not surprisingly then experts hold the view that large scale adoption of vermin composting technology paves the way for the generating wealth from the waste.

 

In the field studies the application of this compost fortified with micro nutrients and microbes has been found to be highly beneficial in restoring the productivity of barren land stretch including salt affected areas, Similarly, for many years now, the technology developed to convert urban waste into energy pellets has been in use in many parts of India and the world.

 

The forays made by the Andhra Pradesh Technology Development and Promotion Centre (APTPC) holds the hope of utilizing urban waste for the much needed power generation. As it is, APTPC, which was set up as part of a joint initiative of the Andhra Pradesh Government, Confederation of Indian Industry (CII) and the Technology Information, Forecasting and Assessment Council (TIFAC) of the Department of Science and Technology (DST) has been driving home the point that finding land fill sites for more than 50 million tonnes of municipal solid waste is a difficult and challenging task. Moreover, the prevailing practice of dumping and burning wastes in landfill sites could cause a lot of health hazards in addition to environmental deterioration. For once the garbage id dumped in the landfills, it could seep into subsoil water, posing a threat to the drinking water sources.

 

But then as pointed out by a spokesman of the APTPC, the urban solid waste can be used to produce both energy and compost. Right at the moment the Centre has been supporting companies in Andhra Pradesh to set up garbage-to-power plants with a total processing capacity of 3,000 tonnes per day. It is also providing consultancy to firms and agencies in Karnataka and Kerala to set up waste to energy plants.
Interestingly, Europe treats 50-million tonnes of waste per year in about 400 waste to energy plants. Similarly, around one hundred waste-to-energy plants in the United States produce close to 2,800 MW of power.

 

Shiva Prasad, an Indian engineer who had obtained a patent for his waste-to-energy process in 1989, could not find any taker for his technology in his home country. However, now his technology is being used to set up a 99-MW power plant based on urban waste in Malayasia. The technology developed by Prasad involves sorting of urban refuse by size and type using rotary screens, vibrating sieves and spikes. Consequent upon the separation of large plastic and metal pieces, the remaining garbage is shredded and dried.

 

Thereafter, the light combustible waste is separated from heavy non combustible part. The combustible waste is then compacted into pellets and burnt into the plant. Not surprisingly then an elated Prasad says: “The Malayasian Government is taking keen interest in this project and the large scale application of this technology is now a distinct possibility”.

 

It is high time that the Indian urban centres started adopting innovative technologies such as the ones developed by Prasad for an easy, profitable and environmentally friendly disposal of ever growing mountain of urban waste.

 

(Credits Radhakrishna Rao, INFA

CentralChronicle)