Analysis of the effects of temperature, the amount of nutrient solution and the carbon dioxide concentration on methane biofiltration

Abstract

Landfi ll gas emissions contribute to the greenhouse effect due to the presence of methane (CH 4 ). CH 4 emissions from old and small landfi lls can be reduced by using biofi ltration. The objective of this study was to optimize parameters that control CH 4 removal in a biofi lter. Temperature is one of the important parameters as well as the amount of nutrient solution (NS) supplied. The effects of the carbon dioxide (CO 2 ) concentration on CH 4 biofi ltration were also studied. Four biofi lters using an inorganic fi lter bed were studied under similar conditions: an inlet CH 4 concentration of 7000 ppmv and an air fl ow rate of 0.25 m 3 /h. A NS was supplied daily. The temperature was varied from 4°C to 43°C. The highest performance was obtained in the range of 31–34°C with an elimination capacity (EC) of 30 g CH 4 /m 3 /h for an inlet load (IL) of 80 g CH 4 /m 3 /h. The effect of the amount of NS supplied to the biofi lter at ambient temperature was also analyzed. The EC was 23 g CH 4 /m 3 /h for both 101 L NS /m 3 V bed /d and 34 L NS /m 3 V bed /d, but it fell to 17 g CH 4 /m 3 /h at 17 L NS /m 3 V bed /d. CO 2 concentrations were varied from 650 to 18,500 ppmv and no effect was noticed on the EC which remained constant at 18 g CH 4 /m 3 /h for an inlet load of 72 g CH 4 /m 3 /h.