ARCHIVED REPORTS_XR0011715 - Laserfiche WebLink

Home Browse Search

a S r — Mf Ri N i.y�•C��14 III. MICRBIAL ENUMERATION j • The total microbial population and the population of bacteria that utilize hydrocarbons as a source of carbon and energy were enumerated In the soil using serial dilution technique followed by plating on nutrient agar plates. The results are summarized In Table 2. { Table 2: MICROBIAL ENUMERATION OF THORPE OIL BOIL COLONY FORMING UNITS (CFU) r; Sample Total Microbial Population Specific Degraders (CFU)* (CFU) SMPL #1 1.07 X 107 6.40 X 108 SMPL #S 3.27 X 107 2.26 X 101 * measured as hexadecane degraders The above results Indicate that Thorpe Gil sods contained a healthy microbial population of indigenous microorganisms with high percentage of hexadecane degraders that could be stimulated and supplemented to enhance the biological degradation of petroleum hydrocarbon constituents. r IV. SOIL RESPIROMETRIC TEST The nutrient and water canditfons for the degradation 6fpetrcleum hydrocarbon contamination In Thorpe Oil soil were optimized and then r assessed by simple resplrometdc analysis. The biodegradation rate was Indirectly monitored by the mgular determination of COO production over a period of113 days. Fertilizer concentrates containing sufficient concentrations of KCI, iCzHPO4 end urea were used to supplement biodegradation and enhance bacterial growth The treatment also included Inoculation with hydrocarbon degrading microorganisms from Treatekis.C61ture collection. The results in Figure 1 represent the mean CO2 productlon�ffom-duplicate teats and duplicate controls. It can be seen that, the test soil, supplemented by nutrients and inocula, showed an Increased rate of degradation over the untreated controls during the duration of study. T"Table 3 gives the actual number of CO. production in srnOles. �p�riy ac r_ • 2