We evaluated the biodegradability of physically (WAF) and chemically (CEWAF) dispersed oil in brackish water (salinity ~6.5g/L), and the influence of nutrient availability (low nutrient-LN: background water vs. high nutrient-HN: addition of 100mgNO3-N/L and 10mg PO4-P/L to background water) on oil biodegradation rates at 15±0.5°C for 42days. No oil removal occurred in WAF compared with CEWAF: 24% in HN and 14% in LN within two weeks. The oil biodegradation concerned mainly alkanes as confirmed by GC/MS analyses. Higher O2 consumption (10.30mgL-1day-1) and CO2 production (3.89mg CL-1day-1) were measured in HN compared with LN (O2: 2.79mgL-1day-1, CO2:0.18mg CL-1day-1). Estimated biomass of hydrocarbon degraders and heterotrophic bacteria was at least an order of magnitude larger in HN than in LN. Combining dispersants with nutrients could enhance oil biodegradation and help improve oil spill mitigation responses.
All Science Journal Classification (ASJC) codes
- Aquatic Science
- Brackish water
- Endicott oil
- Oil spill