| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4364392 | International Biodeterioration & Biodegradation | 2015 | 9 Pages |
•This is the first study evaluating calcium-gel entrapped bacteria in diesel degradability in seawater.•Among the four deisgns, the optimal combination CC-HCCH11: CC-JG39 = 5: 1.•The entrapped bactera, as a seeding process, can continuously be released for diesel degradation in seawater.•The suspended free cells only achieved half of the degradability of the entrapped bacteria cells.
The objective is to determine an optimized combination of immobilized cell when remediating diesel-oil contaminated seawater. Experiments were conducted using the diesel-degrading bacteria: Rhodococcus pyridinivorans CC-HCCH11, Gordonia alkanivorans CC-JG39, and Alcaligenes piechaudii CC-ESB2. They were entrapped in calcium alginate gel beads. All of the combinations were evaluated with the total petroleum hydrocarbon-diesel (TPHd) degradability in modified Bushnell Haas medium by baffled flask tests. Design I (dominant CC-HCCH11) achieved the highest TPHd degradation percentage (78%), followed by Design II (75%), Design III (70%), and Design IV (61%). Design I reduced TPHd from initial 2342 mg/L to 504 mg/L, and also achieved the highest 1st order kinetic rate (0.0049/hr) followed by Design III (0.0046/hr), Design IV (0.0042/hr), and Design II (0.0022/hr). A parallel batch result showed that the free-cell Design I revealed only about half of the TPHd degradability. Nutrient test showed that Bushnell Haas medium was adequate for the remediation.
