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RELATIONSHIP BETWEEN BACTERIAL NUMBERS, DEPTH, AND MOISTURE CONTENT OF SOLID WASTE SAMPLES FROM A FULL-SCALE MUNICIPAL LANDFILL AT OUTER LOOP
Citation:
DavisHoover*, W J. AND R. G. Kavanaugh**. RELATIONSHIP BETWEEN BACTERIAL NUMBERS, DEPTH, AND MOISTURE CONTENT OF SOLID WASTE SAMPLES FROM A FULL-SCALE MUNICIPAL LANDFILL AT OUTER LOOP. 7th Annual SWANA Landfill Symposium, Louisville, KY, 6/17-19/02.
Description:
Core samples of refuse from different depths within the Outer Loop Landfill, Louisville, KY, a full-scale operating municipal landfill, were obtained using a 3ft diameter bucket auger. The samples were processed and liquid extracts were obtained. The moisture content of the extracted samples was determined. Five functional groups of bacteria aerobes, anaerobes, denitrifiers, sulfate reducers and methanogens were enumerated in the solid waste extracts. The relationship between the moisture content of the sample and the microbial numbers were examined along with the relationship between the microbial numbers and the depth from which the sample came. The analysis shows that there is no statistically significant correlation between moisture content (47-65%) of the wastes and the numbers of different groups of bacteria at different depths. Comparison of the moisture content and the depth of the samples yielded an r2 of 0.027. The relationship between moisture content and aerobes (r2=0.085), total anaerobes (r2=0.179), sulfate reducers (r2= 0.185), and denitrifiying bacteria (r2= 0.048) did not result in a statistically significant correlation. The relationship between the numbers of different groups of bacteria and depth for two corings, coring 1 and coring 2, were also analyzed. No correlation between numbers and depth was found for any functional group. However, strong correlations between aerobes and anaerobes and anaerobes and methane producers were found from samples from the two corings. Just as moisture content does not correlate with the depth where the sample is found, the counts also, in turn, do not correlate to the depth of the sample. Factors other than the depth and moisture content seem to influence the activity of different functional groups.