Table 6.
Statistical analysis of the significance of hydrocarbon removal efficiency of HDB8, HDB9, and HDB18, with different nitrogen sources and C/N ratios.
| Nitrogen sources | P value at 95% confidence | C : N ratios | P value at 95% confidence | |
|---|---|---|---|---|
| HDB8 | ||||
| Total removal (average) | ∗∗∗ | 4.42E − 06 | ∗∗ | 4.25E − 04 |
| LMW hydrocarbons | ∗∗∗ | 6.40E − 05 | ∗∗ | 0.000596589 |
| MMW hydrocarbons | ∗∗∗ | 1.76E − 05 | ∗∗ | 0.004427376 |
| HMW hydrocarbons | ∗ | 0.01 | ∗∗ | 0.001089686 |
| HDB9 | ||||
| Total removal (average) | ∗∗∗ | 6.56E − 06 | ∗∗∗ | 9.85E − 07 |
| LMW hydrocarbons | ∗∗∗ | 3.86E − 06 | ∗∗∗ | 2.72E − 07 |
| MMW hydrocarbons | ∗∗∗ | 4.73E − 05 | ∗∗ | 0.005285635 |
| HMW hydrocarbons | NS | 0.08 | ∗∗∗ | 1.2505E − 06 |
| HDB18 | ||||
| Total removal (average) | ∗∗∗ | 5.80E − 05 | ∗ | 0.021019569 |
| LMW hydrocarbons | ∗∗∗ | 2.80E − 05 | ∗∗∗ | 1.56095E − 06 |
| MMW hydrocarbons | ∗∗∗ | 3.64E − 05 | ∗∗∗ | 2.7128E − 06 |
| HMW hydrocarbons | ∗ | 0.04 | ∗∗ | 0.000160478 |
NS: not significant. ∗Significant. ∗∗Highly significant. ∗∗∗Very highly significant.
LMW: low molecular weight; MMW: medium molecular weight; HMW: high molecular weight.