Performance Evaluation of Phytocapping As Covering For Sanitary Landfill Sites

Abstract

Commonly adopted method for discarding of Municipal Solid Waste (MSW) is disposal on landfill sites. The practice involves treatment of MSW before disposal, which is infrequent in most of the places in India. With the disposal of untreated waste, the biodegradation of MSW triggers the formation of Landfill Gases (LFG). Moreover, the closer of aged landfill must be practiced with application of soil over the layer of last dumped waste, which is also infrequent, in turn the landfills are used until management thinks they can. This unplanned and haphazard use of landfill creates countless environmental hazard. To overcome this approach, the present paper focuses on a novel idea of closure of landfill by the application of vegetation (phytocaps) on its top. In the experiment three planters were used each depicting solid waste disposal site. Two planter P1 and P2 depicts MSW landfill sites with application of phytocaps and planter P3 portrays conventional MSW landfill sites. Five Indian species of plants, commonly named as Basil, Lemon grass, Indian Mustard, Sunflower and Lily with locally available soil were taken in experiment for evaluation of phytocaps for covering of landfill sites. The implementation of plants decreases the amount of nutrients and heavy metals in leachate, thereby decrease in threat of groundwater pollution. They also enhance the methane oxidation in soil. Roots of plants absorbs the essential nutrients from the soil leading to the bio-availability of oxygen for the methanotrops to oxidize the CH4. The leachate characteristics, plant height, root depth, heavy metal uptake by roots, chlorophyll analysis and methane emission analysis from each planter were studied. The experiment resulted in 60-63% of reduction in methane emission in planter 1 and 2 while the emission in planter 3 increased with the course of time. Similarly, leachate samples from planter 1 and 2 showed reduction of 99% COD, 95-99% heavy metals, 75-82% nutrients and pH was found to be alkaline.