Methane and carbon dioxide emission and leachate characterization from landfills along ganges river at varanasi ( u . p . ) , india

Landfills are now considered to be among the largest anthropogenic source of green house gas (GHG) emission in the world. Methane and carbon dioxide emission rates were studied at two landfill sites along the Ganges river at Varanasi (U.P.), India. Chemical characteristics of leachates emerging from both the landfills were also studied. Overall, the emission rates ranged from 10.73 to 60.20 mg CH4 m -2 h-1 and from 17.28 to 281.27 mg CO2 m -2 h-1. Emissions increased sharply with rising temperature in summer months. The rates were higher at young landfill site and between site differences in CH4 and CO2 emissions were significant. Landfill sites differed also with respect to leachate characteristics. The BOD5: N: P ratio averaged to 90 : 3 : 1 at Site 1 and 80 : 2 : 0.5 at Site 2 indicating that, for leachate treatment, the aerobic biological systems may operate successfully without nutrient supplement. Although, more exhaustive data sets are needed, the present study, that forms the first report on GHG emission from Varanasi landfills, will help reducing uncertainties in CH4 and CO2 emission estimate scenario.