Temperature Inside The Landfill: Effects Of Liquid Injection And Ambient Temperature

Publication Year:
2007
Usage 21
Downloads 16
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Repository URL:
http://stars.library.ucf.edu/etd/3233
Author(s):
kumar, Amit
Tags:
landfill; MSW; temperature; moisture
thesis / dissertation description
This study represents an analysis of comprehensive temperature and moisture content data collected from the anaerobic portion of a bioreactor landfill at the New River Regional Landfill, Florida, USA. The main focus of the study was the analysis of effects of the liquid injection on the temperature inside the landfill. When the leachate or groundwater at lower temperature than the landfilled waste is injected into the landfill, it has an initial cooling effect on the waste until the biological activity, enhanced by the additional moisture, releases heat. This cooling effect was tested in the study to determine whether it could be used to track moisture arrival as an alternative to moisture sensors. First of all, this hypothesis of cooling effect was tested at the injection wells by correlating temperature drops at the injection wells with known injection events. Then the temperature drop events were identified at monitoring locations where temperature and moisture sensors were co-located. The identification step at the monitoring wells was more difficult than in the case of the injection wells because the cooling effect at the injection well is more pronounced than at the monitoring sites, located 7.62 m away from the point of injection. From the analysis it was found out that, overall, the temperature drop at monitoring locations brought about by the injected liquid is a good criterion for tracking the moisture arrival, however only at the first arrival of moisture. Of all of the cases studied, temperature was able to indicate the moisture arrival for 85% of the times at the first injection as opposed to 36% overall. The difference was attributed to the stimulation of biological activity and subsequent heating of the injected liquid as it moves through the waste. Another focus of the research was the estimation of the waste quantity (volume) wetted from the injection. It was assumed that complete mixing takes places between injected liquid and the moisture already present in the waste and that the temperature of the injected liquid is the ambient temperature. According to the results, there was a significant gap between the expected and the actual wetted volume. The waste volume actually wetted was ≤ 1% to 9% of the total waste volume expected to be wetted. Also studied was the effect of ambient temperature on the waste temperature. It was observed that the ambient temperature has no effect on the global temperature inside a bioreactor landfill even at a shallow depth of 4.6 m. While analyzing the trend of waste temperature inside the landfill, liquid injection was found to lead to an increase in temperature.