‘ Bioreactor Landfills ’ – a Global Vista on the Emerging Technology for Sustainable Management of Municipal Solid Waste

To use land as a repository for materials that can be assimilated without adverse impacts on the environment has been the fervour of landfill managers all around the globe. While it is inevitable that a landfill will receive an assorted range of materials from municipal sources pretreatment and processing of the waste dumped has been constantly looked upon as a commendable option. Operating landfills as bioreactors and hence enhancing the stabilization of waste is one such option that has been elaborately investigated and have also already been in practice in a few American and European countries. This paper gives a tangible view of the many benefits of the multifaceted approach evident from the past and ongoing laboratory and field trials and culminates with the need for research on the promising technology in India. As garnered from literature, research on bioreactor landfills have focused on shifts in bulk parameters of leachate produced, stabilization rates and gas emission rates and the effect of pH control, shredding, compaction, ponding, cover and liner, water, nutrient and sludge addition. Notable merits among these have been reported to be quicker stabilization of waste and amplified gas production. Some auxiliary advantages of this kind of operation include distribution of nutrients and enzymes, pH buffering, dilution of inhibitory compounds, recycling and distribution of methanogens, liquid storage and evaporation opportunities at low additional construction and operating cost. From lab-scale demonstrations to full fledged landfilling facilities, bioreactor landfills have been given due importance and hence constantly pondered into by environment conscious countries like United States of America, United Kingdom, Germany and Australia. India should also join the line by initiating research on this admirable technology option and concentrate on areas reflecting expected reactions occurring within the landfill by characterization of leachate which will help to provide information on waste degradation phases an important insight that is yet to be revealed. Other focus areas can include design and operating criteria that suit Indian conditions, with special attention to leachate recirculation, gas entrapment and feasibility of applying the technique for reclamation of tons of garbage heaps in existing dumping grounds of the country.