ISSN:
1573-2932
Keywords:
biodegradation
;
hydrocarbon
;
nitrogen
;
nutrient ratios
;
phosphorus
;
soils
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract The biodegradation of hexadecane (C as hexadecane-C) was assessed under 34 different external nitrogen (N supplied as NO3-N) and phosphorus (P supplied as PO4-3-P) supply conditions in order to determine how different nutrient formulations affected nutrient limitation conditions during degradation. CO2 production yields indicated that shifts in N and P supply levels resulted in variable biodegradation responses due to shifts in the limiting-nutrient (e.g., from N to P). For example, the estimated maximum fractional CO2 yield ratio was 0.24 (mg CO2-C produced mg-1 hexadecane-C) for P-limited nutrient formulations (P:hexadecane-C〈0.01), whereas the yield ratio was more than two times greater when the system was not P- limited. Similar effects were observed for N-limited (N:hexadecane- C〈0.15) versus non-N-limited formulations. The relative bioavailability of natural soil-N and soil-P also was examined. In the soil studied, background soil-N was 96.3% organic-N and was found to be largely nonbioavailable. In contrast, high CO2 yields were observed even when no external P was supplied. An iterative mathematical procedure indicated that the Olsen soil-P subfraction (inorganic soil-P plus soluble organic soil- P) best approximated bioavailable soil-P for this soil. Our results indicate that both N and P additions affect biodegradation yields, but that stoichiometrically inappropriate nutrient mixes produce suboptimal CO2 yields. We also found that the bioavailable fractions of soil-N and soil-P should be incorporated into estimating the most suitable nutrient formulations for a given contamination scenario.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005091427942
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